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A study of the muskox (Ovibos moschatus) in relation to its environment Tener, John Simpson 1960

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A STUDY OF THE MUSKOX (OVIBOS MOSCHATUS) IN RELATION TO ITS ENVIRONMENT by JOHN SIMPSON TENER B.A,, U n i v e r s i t y of B r i t i s h Columbia, 1943 M.A., U n i v e r s i t y of B r i t i s h Columbia, 1952 A THESIS SUBMITTED IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF Doctor of Philosophy i n the Department of Zoology We accept t h i s t h e s i s as conforming to the r e q u i r e d standard THE UNIVERSITY OF BRITISH COLUMBIA A p r i l , I960 In presenting t h i s t h e s i s i n p a r t i a l f u l f i l m e n t of-the requirements f o r an advanced degree at the U n i v e r s i t y of B r i t i s h Columbia, I agree that the L i b r a r y s h a l l make i t f r e e l y a v a i l a b l e f o r reference and study. I f u r t h e r agree that permission f o r extensive copying of t h i s t h e s i s f o r s c h o l a r l y purposes may be granted by the Head of my Department or by h i s r e p r e s e n t a t i v e s . I t i s understood that copying or p u b l i c a t i o n of t h i s t h e s i s f o r f i n a n c i a l gain s h a l l not be allowed without my w r i t t e n permission. The U n i v e r s i t y of B r i t i s h Columbia, Vancouver £, Canada. P U B L I C A T I O N S 1951 Sixth census of non-passerine birds in the bird sanctuaries of the north shore of the Gulf of St. Lawrence. The Can. Field-Nat. 65(2): 65-68. 1954 Beaver.mortality. Wildl . Mgt. Papers delivered at 18th Fed.-Prov. W i l d l . Conf., Ottawa, June, 1954. Dept. North. Aff. and Nat. Res., Ottawa, pp 35-38. 1954 A preliminary study of the muskoxen of Fosheim Peninsula, Ellesmere Island, N . W . T . Dept. of North. Aff. and Nat. Res. Wildl . Mgt. Bull. Ser. 1, No. 9, 34 pp. 1954 Facts about Canadian muskoxen. Trans. 19th N . A m . W i l d l . Conf., pp. 504-510. 1954 Three observations of predators attacking prey. The Can. Field-Nat. 68(4): 181-182. T£ 1956 Gross composition of muskox milk. Can. Jour. Zool. 34 (4). 1956 Annotated list of birds of part of the Back River, N . W . T . The f, Can. Field-Nat. 70(3): 138-141. 1958 The distributon of muskoxen in Canada. Jour. Mamm. 39(3):, 398-408. 1958 with Harold C . Gibbs. On some helminth parasites collected from the muskox (Ovibos moschatus) in the Thelon Game Sanctuary, Northwest Terri-tories. Can. Jour. Zool. 39(4): 529-532. * 1958 with A . W . F. Banfield. A preliminary study of the Ungava caribou. Jour. Mamm! 39(4): 560-573. ,1959 Wildlife studies in, Operation Hazen, narrative and preliminary' reports 1957-58. Def. Res. Bd., Dept. of Nat. Def. pp. 86-88. I960 The present status of the barren-ground caribou. Can. Geog. '%\\t ;Mmiu>rsiiy uf British (iloiimtlita Faculty of Graduate Studies PROGRAMME OF THE FINAL ORAL E X A M I N A T I O N FOR T H E D E G R E E OF DOCTOR OF PHILOSOPHY J O H N SIMPSON T E N E R B.A., University of British Columbia, 1948 M . A . , University of British Columbia, 1952 IN R O O M 3332, B I O L O G I C A L SCIENCES B U I L D I N G M O N D A Y , M A Y 2, 1960 A T 10:00 A . M . COMMITTEE IN CHARGE Dean F. H . S O W A R D : Chairman J. R. A D A M S P. A . L A R K I N I. M c T . C O W A N J . R. M A C K A Y W. S. H O A R N. V. S C A R F E V. K R A J I N A A. 1. W O O D External Examiner: A. S T A R K E R L E O P O L D University of California A STUDY OF THE MUSKOX (OVIBOS MOSCHATUS) IN RELATION TO ITS ENVIRONMENT ABSTRACT A studv of the muskox (Ovibos moschatus) in relation to its environment was carried out in the Canadian Arcri'- between 1952 and 1959. Environmental factors such as climate, soils and summer and winter range vegetation were examined. The numbers, distribu-tion, population structure, behaviour and general biology of musk-oxen were studied. Muskoxen live in an Arctic environment of short cool summers, long, cold winters and relatively little snow. Range studies at the southern and northern limits of muskox distribution in Canada revealed major differences in plant species occurrence, annual pro-duction and chemical values. The summer ranges in the Thelon Game Sanctuary produced more woody food species than Lake Hazen ranges and were calculated to support as many as seven times the number of muskoxen. Thelon winter ranges may support up to ten times' as manv muskoxen as Lake Hazen winter ranges of com-parable size. Total annual forage production in the Thelon compares favourably with forage production on mountain sheep and elk ranges in Jasper and Banff National Parks. Summer and winter food habits of the species were determined. Chemical analyses of the important foods revealed that adequate amounts of protein, carbohydrates, calcium and phosphorous, with perhaps less fat than desirable were available to muskoxen on Thelon summer ranges. Thelon winter range foods contain less phosphorous than recommended for range cattle, which conceivably could inter-fere with reproductive performance. Lake Hazen summer and winter range foods appeared to be nutritionally adequate although low forage production may affect population growth adversely. Muskoxen are slowly increasing in most areas in the Arctic where they occur. Studies of age structure in herds indicate that calf production is low by most ungulate standards. The muskox exhibits a number of adaptations to Arctic living. Its short limbs, dense inner and outer hair and its generally slow movements contribute to heat conservation. As a ruminant, the muskox synthesises Vitamin B and proteins. Food probably is stored in summer in the liver for winter use. Lactation is prolonged, up to 15 months at least, which would assist calf survival during winter. The ungulate eye permits feeding during winter darkness. Muskoxen are cosmopolitan feeders, a characteristic essential in areas such as the Arctic where plant growth is sparse. Feeding is not intensive in an area, as herds are widely scattered and move frequently. The relatively late age of sexual maturity in cows and bulls re-ported for wild living individuals, the low percentage of calves in populations studied, the production of calves biennially, the generally low production of food in Arctic regons and the barely adequate nutritive value of winter food species indicate that muskox popula-tions in northern regions will not reach densities which will support intensive utilization. GRADUATE STUDIES Field of Study: Zoology Special Course in Vertebrate Taxonomy I. McT. Cowan Comparative Animal Physiology W. S. Hoar Animal Fluctuations P. A. Larkin Quantitative Zoology P. A. Larkin Animal Ecology C S. Elton Other Studies Forest Ecology V. J. Krajina Advanced Plant Taxonomy T. M. C. Taylor A b s t r a c t A s t u d y o f t h e m u s k o x ( O v l b o s m o s c h a t u s ) i n r e l a t i o n t o i t s e n v i r o n m e n t w a s c a r r i e d o u t i n t h e C a n a d i a n A r c t i c b e t w e e n 1952 a n d 1959* E n v i r o n m e n t a l f a c t o r s s u c h a s c l i m a t e , s o i l s a n d s u m m e r a n d w i n t e r r a n g e v e g e t a t i o n w e r e e x a m i n e d . T h e n u m b e r s , d i s t r i b u t i o n , p o p u l a t i o n s t r u c t u r e , b e h a v i o u r a n d g e n e r a l b i o l o g y o f m u s k o x e n w e r e s t u d i e d , M u s k o x e n l i v e i n a n A r c t i c e n v i r o n m e n t o f s h o r t c o o l s u m m e r s , l o n g , c o l d w i n t e r s a n d r e l a t i v e l y l i t t l e s n o w . R a n g e s t u d i e s a t t h e s o u t h e r n a n d n o r t h e r n l i m i t s o f m u s k o x d i s t r i b u t i o n i n C a n a d a r e v e a l e d m a j o r d i f f e r e n c e s i n p l a n t s p e c i e s o c c u r r e n c e , a n n u a l p r o d u c t i o n a n d c h e m i c a l v a l u e s . T h e s u m m e r r a n g e s i n t h e T h e l o n G a m e S a n c t u a r y p r o d u c e d m o r e w o o d y f o o d s p e c i e s t h a n L a k e H a z e n r a n g e s , a n d w e r e c a l c u l a t e d t o s u p p o r t a s m a n y a s s e v e n t i m e s t h e n u m b e r o f m u s k o x e n . T h e l o n w i n t e r r a n g e s m a y s u p p o r t u p t o t e n t i m e s a s m a n y m u s k o x e n a s L a k e H a z e n w i n t e r r a n g e s o f c o m p a r a b l e s i z e . T o t a l a n n u a l f o r a g e p r o d u c t i o n i n t h e T h e l o n c o m p a r e s f a v o u r -a b l y w i t h f o r a g e p r o d u c t i o n o n m o u n t a i n s h e e p a n d e l k r a n g e s i n J a s p e r a n d B a n f f N a t i o n a l P a r k s . S u m m e r a n d w i n t e r f o o d h a b i t s o f t h e s p e c i e s w e r e d e -t e r m i n e d . C h e m i c a l a n a l y s e s o f t h e i m p o r t a n t f o o d s r e v e a l e d t h a t a d e q u a t e a m o u n t s o f p r o t e i n , c a r b o h y d r a t e s , c a l c i u m a n d p h o s p h o r o u s , w i t h p e r h a p s l e s s f a t t h a n d e s i r a b l e w e r e a v a i l a b l e t o m u s k o x e n o n T h e l o n s u m m e r r a n g e s . T h e l o n w i n t e r r a n g e f o o d s c o n t a i n l e s s p h o s -p h o r o u s t h a n r e c o m m e n d e d f o r r a n g e c a t t l e , w h i c h c o n c e i v a b l y c o u l d i n t e r f e r e w i t h r e p r o d u c t i v e p e r f o r m a n c e . L a k e H a z e n s u m m e r a n d 2 2 -w i n t e r r a n g e f o o d s a p p e a r e d t o b e n u t r i t i o n a l l y a d e q u a t e a l t h o u g h l o w f o r a g e p r o d u c t i o n m a y a f f e c t p o p u l a t i o n g r o w t h a d v e r s e l y . M u s k o x e n a r e s l o w l y i n c r e a s i n g i m m o s t a r e a s i n t h e A r c t i c w h e r e t h e y o c c u r . S t u d i e s o f a g e s t r u c t u r e i n h e r d s i n d i c a t e t h a t c a l f p r o d u c t i o n i s l o w b y m o s t u n g u l a t e s t a n d a r d s . T h e m u s k o x e x h i b i t s a n u m b e r o f a d a p t a t i o n s t o A r c t i c l i v i n g . I t s s h o r t l i m b s , d e n s e i n n e r a n d o u t e r h a i r a n d i t s g e n -e r a l l y s l o w m o v e m e n t s c o n t r i b u t e t o h e a t c o n s e r v a t i o n . A s a r u m -i n a n t , t h e m u s k o x s y n t h e s i z e s V i t a m i n B a n d p r o t e i n s . F o o d p r o b a b l y i s s t o r e d i n s u m m e r i n t h e l i v e r f o r w i n t e r u s e . L a c t a t i o n i s p r o l o n g e d , u p t o 15 m o n t h s a t l e a s t , w h i c h w o u l d a s s i s t c a l f s u r -v i v a l d u r i n g w i n t e r . T h e u n g u l a t e e y e p e r m i t s f e e d i n g d u r i n g w i n t e r d a r k n e s s . M u s k o x e n a r e c o s m o p o l i t a n f e e d e r s , e s s e n t i a l i n a r e a s s u c h a s t h e A r c t i c w h e r e p l a n t g r o w t h i s s p a r s e . F e e d i n g i s n o t i n t e n s i v e i n a n a r e a , a s h e r d s a r e w i d e l y s c a t t e r e d a n d m o v e f r e q u e n t l y . T h e r e l a t i v e l y l a t e a g e o f s e x u a l m a t u r i t y i n c o w s a n d . b u l l s r e p o r t e d f o r w i l d l i v i n g i n d i v i d u a l s , t h e l o w p e r c e n t a g e o f c a l v e s i n p o p u l a t i o n s s t u d i e d , t h e p r o d u c t i o n o f c a l v e s b i e n n i a l l y , t h e g e n e r a l l y l o w p r o d u c t i o n o f f o o d i n A r c t i c r e g i o n s a n d t h e b a r e l y a d e q u a t e n u t r i t i v e v a l u e o f w i n t e r f o o d s p e c i e s i n d i c a t e t h a t m u s k o x p o p u l a t i o n s i n n o r t h e r n r e g i o n s w i l l n o t r e a c h d e n s i t i e s w h i c h w i l l s u p p o r t i n t e n s i v e u t i l i z a t i o n . (i) Page I n t r o d u c t i o n 1 Procedures 3 Gross p o p u l a t i o n f i g u r e s and d i s t r i b u t i o n 3 B i o l o g i c a l data 6 Environmental f a c t s 6 Range s t u d i e s 7 P o p u l a t i o n and p h y s i o l o g i c a l s t u d i e s 12 Pathology procedures 15 Behaviour s t u d i e s 16 R e s u l t s 17 Environmental c h a r a c t e r i s t i c s 17 Climate 17 Topography of muskox ranges 22 S o i l analyses 24 S i g n i f i c a n c e of s o i l values i n muskox environment 2$ P l a n t h a b i t a t s 31 Range v e g e t a t i o n 32 Thelon Game Sanctuary 32 Lake Hazen 39 Chemical analyses of muskox food p l a n t s 49 Thelon Game Sanctuary 49 Lake Hazen 54 Feeding h a b i t s 60 D i e t 60 Feeding behaviour 63 I n t e r s p e c i f i c competition f o r food 66 ( i i ) Distribution 68 Former distribution 68 Present distribution 74 Arctic mainland 74 Arctic islands 78 Herd size and composition 6*3 Thelon Game Sanctuary 84 Ellesmere Island 90 Calf crops 95 Yearling counts 96 Reproduction 98 Parasites 100 Bacterial diseases 101 Actinomycosis 101 Brucellosis 102 Abnormalities 102 Skulls 102 Organic 103 Physiological data 103 Blood analysis 103 Fat analysis 104 Milk analysis 104 Rumen cil i a t e s 104 Organ weight and rectal temperature 105 Discussions of the physiological data 106 ( i i i ) M o r t a l i t y 109 P r e d a t i o n 112 Diseases 113 Accidents: 113 Behaviour 113 S o c i a l behaviour 113 S o l i t a r y b u l l s 117 Prebreeding behaviour 119 Mating behaviour 122 Other behaviour 124 D i s c u s s i o n of r e s u l t s 126 Range v e g e t a t i o n analyses 126 Chemical analyses of muskox food p l a n t s and t h e i r r e l a t i o n to muskox n u t r i t i o n 129 D i s t r i b u t i o n 139 Reproduction and p o p u l a t i o n i n c r e a s e 142 T h e o r e t i c a l c o n s i d e r a t i o n of the i n t r i n s i c r a t e of n a t u r a l i n c r e a s e 152 Adaptations of the muskox to the A r c t i c environment 152 Behavioural adaptations 154 P h y s i o l o g i c a l and morphological adaptations 155 B i o l o g i c a l and environmental f a c t o r s i n v o l v e d i n p o p u l a t i o n c o n t r o l 164 Climate 165 B i o t i c f a c t o r s 166 P r e d a t i o n 167 P a r a s i t e s 167 Diseases 168 ( i v ) Reproductive r a t e 168 Food competition 168 Food q u a n t i t y and q u a l i t y 169 D i s c u s s i o n 170 Recommendations f o r u t i l i z a t i o n 172 Future research problems 176 A study i n v a r i a t i o n of the s k u l l and body measurements of the subspecies of muskoxen 176* M a t e r i a l examined 17# H i s t o r y of the systematics of recent muskoxen l£0 Present s u b s p e c i f i c d e s c r i p t i o n l£l D e f i n i t i o n of measurements 1&3 A n a l y s i s of m a t e r i a l 1#5 E x t e r n a l measurements 194 D i s c u s s i o n 197 P o s s i b l e environmental i n f l u e n c e s on muskox v a r i a b i l i t y 201 Conclusions 204 Conclusions of study 205 Acknowledgements 211 B i b l i o g r a p h y 212 Appendix I 225 Appendix I I 252 (v) Table I Table I I Table I I I Table IV Table V Table VI Table V I I Table V I I I Table IX Table X Table XI Table X I I Table X I I I Table XIV Table XV L i s t of Tables Page A e r i a l muskox dates,' areas and hours flown, A r c t i c mainland and i s l a n d s 5 Climate comparisons of the Thelon Game Sanctuary and northern Ellesmere I s l a n d 20 Annual p r e c i p i t a t i o n d i s t r i b u t i o n 21 S o i l analyses r e s u l t s of samples from Thelon Game Sanctuary 25 S o i l analyses r e s u l t s of samples from Lake Hazen 27 Thelon Game Sanctuary summer ranges I and I I p l a n t species occurrence frequency and area coverage i n per cent 34 Thelon Game Sanctuary w i n t e r range I and I I pl a n t species occurrence frequency and area coverage per cent 36 Dry weight production of s e l e c t e d muskox food species Thelon Game Sanctuary 3$ Lake Hazen summer range t r a n s e c t 1 and 11 p l a n t species occurrence frequency and area coverage i n per cent 40 Lake Hazen w i n t e r range I % t r a n s e c t 1 and 11 p l a n t species occurrence frequency and area coverage i n per cent 44 Lake Hazen w i n t e r range I I p l a n t species occurrence frequency and area coverage i n per cent, 4# p l o t s 45 Dry weight production of s e l e c t e d muskox food s p e c i e s , Lake Hazen, Ellesmere I s l a n d 47 Comparison of forage production of ranges of the Northwest T e r r i t o r i e s w i t h those of pastures of domestic and w i l d ungulates of southern Canada 4# Chemical analyses of muskox food p l a n t s Thelon Game Sanctuary, winter range, 1956 49 Chemical analyses of muskox food p l a n t s Thelon Game Sanctuary, summer and winter ranges, 1957 51 ( v i ) Table XVI Table XVII Table X V I I I Table XIX Table XX Table XXI Table X X I I Table X X I I I Table XXIV Table XXV Table XXVI Table XXVII Table XXVIII Table XXIX Table XXX Table XXXI Table XXXII Chemical analyses of muskox food p l a n t s Lake Hazen, Ellesmere I s l a n d , summer and wi n t e r ranges, 1958 55 Hudson*s Bay Company, muskox f u r r e t u r n s 1862-1900 70 Hudson's Bay Company, muskox f u r r e t u r n s 1901-1916 71 Muskox herd s i z e frequency, a e r i a l and ground observations, Thelon Game Sanctuary, N.W.T. 85 Average herd s i z e , a e r i a l and ground ob s e r v a t i o n s , Thelon Game Sanctuary, 1951 - 1957 88 Muskox herd ground segregations Thelon Game Sanctuary 89 Muskox herd a e r i a l observations Thelon Game Sanctuary 90 Muskoxen herd s i z e frequency a e r i a l and ground observations, Ellesmere I s l a n d , N,W.T. 91 Average herd s i z e , a e r i a l and ground observations Ellesmere I s l a n d , 1951, 1958 and 1959 92 Muskox herd ground observations Ellesmere I s l a n d , 1951, 1954, 1958 93 Muskox a e r i a l observations Ellesmere I s l a n d 94 Gross composition of muskox m i l k i n percentages 104 105 P r e l i m i n a r y l i s t of rumen c i l i a t e s of Ovibos moschatus Organ weights i n pounds and r e c t a l temperatures, a d u l t b u l l muskoxen Weight i n pounds of organs of s e l e c t e d ungulates R e c t a l temperatures i n °F, Age c l a s s and sex of muskox s k u l l s found near Lake Hazen Table XXXIII D a i l y n u t r i e n t allowances f o r beef c a t t l e 106 108 109 110 133 ( v i i ) Table XXXLV Number and o r i g i n of a d u l t b u l l s k u l l m a t e r i a l , by subspecies 179 Table XXXV Tests of s i g n i f i c a n c e s of the d i f f e r e n c e s i n measurements between east and west (north) Greenland a d u l t b u l l s k u l l s 187 Table XXXVI Tests of s i g n i f i c a n c e of the d i f f e r e n c e s i n a l v e o l a r lengths i n three subspecies 190 Table XXXVII R e s u l t s of covariance a n a l y s i s of s i x p a i r s o f measurements taken on s k u l l s from the A r c t i c mainland and A r c t i c i s l a n d s 191 Table XXXVIII "T" t e s t of s i g n i f i c a n c e s of d i f f e r e n c e s i n s k u l l measurements between O.m. moschatus and 0«m» niphoecus 194 Table XXXIX Measurements and weights of a d u l t cow and b u l l muskoxen, from the l i t e r a t u r e and i n the present study 195 Table XL Measurements of c a l f muskoxen, Thelon Game Sanctuary 196 Table XLI T o t a l l e n g t h 227 Table X L I I Basal l e n g t h 227 Table X L I I I Least o r b i t a l width 228 Table XLIV P a l a t a l l e n g t h 228 Table XLV Greatest zygomatic width 228 Table XLVI Mastoid width 229 Table XLVII Distance between Lamdoidal Crest and A n t e r i o r edge of Nasals 229 Table X L V I I I P o s t - d e n t a l l e n g t h 229 Table XLIX B a s i o c c i p e t a l width 230 Table L Least width of s k u l l between horns and orbits 230 Table L I Greatest o r b i t a l width 230 Table LIT. P a l a t a l width a t M^ 231 Table LIII P r e m a x i l l a e width 231 Table LIV Nasal width 231 ( v i i i ) Table LV Nasal l e n g t h 232 Table LVI Least d i s t a n c e between s u p r a o r b i t a l foramina 232 Table LVII P r e a l v e o l a r l e n g t h 232 Table L V I I I A l v e o l a r l e n g t h 233 Table LIX P o s t - p a l a t a l width 233 Table LX Width of p a l a t e a t PM2 233 Table LXI Mastoid width on ba s a l l e n g t h 234 Table LXII Greatest zygomatic width on ba s a l l e n g t h 235 Table LXIII Width of p a l a t e a t PM 2 on ba s a l l e n g t h 236 Table LXIV Width of p a l a t e a t M3 o n b a s a l l e n g t h 236 Table LXV Width of p a l a t e a t M 2 on a l v e o l a r l e n g t h 238 Table LXVI Greatest zygomatic width on a l v e o l a r l e n g t h 239 ( i x ) L i s t of Figures Page Figur e 1. Map of the Northwest T e r r i t o r i e s 2 Fig u r e 2. A e r i a l surveys of muskox populations A r c t i c mainland of Canada, 1951-57 9 F i g u r e 3 . Locations of muskoxen observed and of range survey s i t e s , Thelon Game Sanctuary 9 Figure 4 . Locations of Lake Hazen range survey s i t e s 9 F i g u r e 5. Per cent frequency of herd s i z e s , Thelon Game Sanctuary 86 F i g u r e 6 . T o t a l l e n g t h 240 F i g u r e 7 . Basal l e n g t h 240 F i g u r e S. Least o r b i t a l width 240 Figure 9 . P a l a t a l l e n g t h 240 Figure 1 0 . Greatest zygomatic width 240 Figure 11. Mastoid width 240 Figure 1 2 . Distance between lambdoidal c r e s t and a n t e r i o r edge of nasals 240 Figure 13. P o s t - d e n t a l length 240 F i g u r e 14. B a s i o c c i p i t a l width 241 F i g u r e 1 5 . Least width of s k u l l between horns and o r b i t s 241 F i g u r e 1 6 . Greatest o r b i t a l width 241 F i g u r e 17. P a l a t a l width a t M3 241 F i g u r e 18. P r e m a x i l l a e width 241 Figure 1 9 . Nasal width 241 F i g u r e 2 0 . Nasal l e n g t h 241 Figure 2 1 . Least d i s t a n c e between s u p r a o r b i t a l foramina 241 Figure 22. P r e a l v e o l a r l e n g t h 242 F i g u r e 2 3 . A l v e o l a r length 242 (x) Figure 24. P o s t - p a l a t a l width 242 Figure 25. Width of p a l a t e a t PM 2 242 Figure 26. Adult b u l l muskox, Thelon Game Sanctuary. August, 1955. Photograph by Mr. John J.Teal 243 Fig u r e 27. Base camp during winter s t u d i e s . Thelon Game Sanctuary. March 26 to A p r i l 29, 1956 244 F i g u r e 28. Herd of 30 muskoxen on f l a t p l a t e a u country, north of Thelon R i v e r . March 28, 1956 244 Figure 29. Attu n g a l a , Eskimo a s s i s t a n t beside a d u l t cow muskox c o l l e c t e d i n Thelon Game Sanctuary. A p r i l 5, 1956 244 Figure 30. K n i f e i n d i c a t e s t y p i c a l l y shallow snow cover Ledum decumbens. A p r i l 4, 1956 244 Figure 31. Muskox feeding areas on p l a t e a u north of Thelon R i v e r . Snow cover has been pawed on dark areas. A p r i l 4, 1956 245 Figure 32. W. Holsworth viewing f l u v i a l w i l l o w f l a t of Transect 1 of summer range s t u d i e s , Thelon Game Sanctuary, J u l y 2 3 , 1957 245 Fig u r e 33. W. Holsworth beside S a l i x a l a x e n s i s bushes on Transect 1, Thelon Game Sanctuary. J u l y 23, 1957 245 Figure 34. Summer range study area I I , Thelon Game Sanctuary. J u l y 30, 1957 245 Fig u r e 35. W. Holsworth on win t e r range study area I , Thelon Game Sanctuary. J u l y 31, 1957 246 Figure 36. Winter range study area I I , Thelon Game Sanctuary. August 3, 1957 246 F i g u r e 37. Panoramic view to t h e northwest of the base camp ( r i g h t ) a t Lake Hazen, Ellesmere I s l a n d . Note t y p i c a l d i s t r i b u t i o n of w i l l o w clumps. Mount Ubyssey i s a t r i g h t centre. August 13, 1958 247 F i g u r e 38. Panoramic view of the northwest i l l u s t r a t i n g f l a t lands between h i l l s and Lake Hazen. Mount Ubyssey i s at l e f t and Johns I s l a n d at r i g h t . August 13, 1958 247 (xi) Figure 39. Panoramic view from east end of Lake Hazen, looking southwest down the lake. Note range of h i l l s and Ellesmere Island Ice Cap at right. June 26, 1958 248 Figure 40. Typical late winter snow cover i n valleys. Snow Goose River valley, Lake Hazen. June 4, 1958 248 Figure 41* Snout of unnamed glacier from ice cap. Note muskoxen feeding on h i l l s i d e at right. June IS, 1958 248 Figure 42. Summer range at the foot of Mt. Ubyssey, Lake Hazen. J.S. Tener measuring vegetation. , Note muskox at foot of pale h i l l . July 22, 1958 249 Figure 43. Transect 1, plot 1, of summer range study. Plants includedPoa glauca. Melandrium t r i f l o -rum, Erysimum pallasii„ Agropyron latiglume. etc. Lake Hazen. July 22, 1958 2 49 Figure 44. Transect 1, plot 11, of summer range study. Plants includedSalix arctica. Dryas inte-g r i f o l i a . Kobresia myosuroides. Lake Hazen, July 22, 195"§ 249 Figure 45. Transect 1, plot 25, summer range study. Plants included Oxyria digyna and Agropyron latiglume. Lake Hazen. July 22, 1958 249 Figure 46. Transect 1, winter range study, 1480* above sea l e v e l . J.S. Tener measuring vegetation. Plants included Carex stans f Eriophorum  scheuchzeri. Saxifraga sp., Polygomum v i v i -parum. Salix arctica. Lake Hazen. July 23, t$W~ 250 Figure 47. Transect 1, plot 18, winter range study. Drier part of upper valley below Mt. Ubyssey. Plants included Arctogrostis l a t i f o l i a . Salix arctica. Dryas i n t e g r i f o l i a . Luzula sp., Alopecurus alpinus. Lake Hazen. July 23,1958 250 Figure 48. Transect 1, winter range study. Note density of vegetation such as Salix arctica and Carex  stans. Saxifraga hircuius i s i n centre. Lake Hazenl July 23, 1958 250 Figure 49. Typical density of Carex stans, growing i n wet stream beds. Mt, Ubyssey, Lake Hazen. July 22, 1958 250 ( x i i ) Figure 50, Transect 2, winter range study, 16801 above sea level, at foot of Mount Ubyssey. Lake Hazen. July 23, 195# 251 Figure 51• Remains of an adult bull muskox i n creek bed on slope at foot of Mt. Ubyssey. Lake Hazen. July 22, 1958 251 Figure 52. Pit dug by a muskox on a 1630 f t . ridge on slope of Mt. Ubyssey. Lake Hazen. July 23, 1958 251 A Study of the Muskox (Qvibos moschatus) i n . R e l a t i o n to i t s Environment  INTRODUCTION The muskox (Qvibos moschatus subsp,) i s one of two ungulates l i v i n g i n the A r c t i c regions of Canada, A study of the animal and i t s environment would e l u c i d a t e some of. the problems the species encounters i n l i v i n g i n the A r c t i c and would add to the fund o f knowledge of A r c t i c animals g e n e r a l l y . The muskox has been the subj e c t of numerous r e p o r t s by explorers and s c i e n t i s t s but f o r the most p a r t those r e p o r t s were concerned w i t h observations of the animals l i f e h i s t o r y and behaviour. I t was d e s i r a b l e t h a t f u t u r e s t u d i e s of the animal be d i r e c t e d to gathering i n f o r m a t i o n on the nature of i t s environment and of the ways i n which the species has adapted to tha t environment. This t h e s i s i s a re p o r t of the r e s u l t s of such a study of muskoxen the author c a r r i e d out f o r the Canadian W i l d l i f e S e r v i c e i n the Canadian A r c t i c f o r a number of years be-tween 1952 and 1959. A t o t a l of t h i r t e e n months was. spent i n the f i e l d w h i l e engaged i n the study. For a review of muskox d i s t r i b u t i o n and b i o l o g y as they- were known up to the year 1934, the reader i s r e f e r r e d to Hone (1934), i t i s evident t h a t much good i n f o r m a t i o n had been c o l l e c t e d by ex-p l o r e r s and other t r a v e l l e r s i n Greenland and the Canadian A r c t i c . Q u a n t i t a t i v e s t u d i e s of a po p u l a t i o n and i t s ecology, however, had not been made and the W i l d l i f e S e r v i c e b e l i e v e d a c o n t r i b u t i o n to knowledge might r e s u l t through such s t u d i e s . The muskox i s a comparatively r a r e animal i n Canada; some 5000 are b e l i e v e d t o e x i s t (Tener, 1958). l t became apparent i n the e a r l y phases of the study t h a t f a c t s about muskox b i o l o g y would not be easy to gather. For t h i s reason i t was decided to s e l e c t areas r e p o r t e d to have c o n c e n t r a t i o n s of the animals which c o u l d be s t u d i e d r e l a t i v e l y e a s i l y . Northern E l l e s m e r e I s l a n d and the Thelon Uame Sanctuary, on the A r c t i c mainland, were two such areas ( F i g u r e I J . The values of these s i t e s are measurably i n c r e a s e d as they are about the n o r t h e r n and southern e x t r e m i t i e s of the Canadian d i s t r i b u t i o n of the s p e c i e s , thus p e r m i t t i n g com-p a r i s o n s of the environments and p o p u l a t i o n s . - 3 -I t was hoped by these s t u d i e s to o b t a i n a t l e a s t t e n t a t i v e answers to questions such as the f o l l o w i n g : 1. How i s the muskox adapted i n terms of behaviour and morphology to the A r c t i c environment? 2. Are there important d i f f e r e n c e s i n t i m i n g of reproduc-t i o n and i n other behaviour over the wide l a t i t u d e of h a b i t a t i o n of the species? 3. What are the b e n e f i c i a l and harmful f o r c e s a c t i n g upon the muskox? Which of these are l i m i t i n g muskox p o p u l a t i o n growth under d e f i n e d circumstances? 4. How has the species responded to p e c u l i a r circumstances of A r c t i c i s o l a t i o n i n terms of subspeciation? An examination of the taxonomic l i t e r a t u r e of muskoxen suggested that s u b s p e c i f i c c l a s s i f i c a t i o n s were tenuous. P r e l i m -i n a r y s t u d i e s of measurements of a l a r g e number of s k u l l s found i n one r e g i o n suggested that the v a r i a t i o n i n s i z e w i t h i n one sub* species may exceed such v a r i a t i o n among the three named subspecies. For those reasons, a study of the v a r i a t i o n i n s i z e of muskox s k u l l s was c a r r i e d out and forms a part of t h i s t h e s i s . PROCEDURES Gross p o p u l a t i o n f i g u r e s and d i s t r i b u t i o n Knowledge of muskox numbers and d i s t r i b u t i o n i n Canada up to the time of the present study were based c h i e f l y on estimates of Anderson (1930) who used i n f o r m a t i o n from records of e a r l i e r ex-p l o r e r s and from R. C. M. P o l i c e r e p o r t s . A f i r s t o b j e c t i v e of the current work was to o b t a i n as accurate an assessment as poss-i b l e of muskox populations i n various A r c t i c r e g i o n s , both f o r - 4 -f u t u r e management purposes and to l e a r n how the species has f a r e d s i n c e i t was protected from hunting i n 1917. The procedures f o l l o w e d to o b t a i n p o p u l a t i o n f i g u r e s and d i s t r i b u t i o n were c a r r i e d out between 1951 and 1955, i n c l u s i v e , and were v a r i e d i n nature. As i t would have been p r o h i b i t i v e l y expensive to c a r r y out a e r i a l surveys to get data, the Canadian W i l d l i f e S e r v i c e s o l i c i t e d the cooperation of aircrews of the Royal Canadian A i r Force, who f l e w over A r c t i c r e g i o n s , to record t h e i r observations of muskoxen on prepared R. C. A. F. forms s u p p l i e d to them. The response was e x c e l l e n t . Other sources of i n f o r m a t i o n were i n v e s t i g a t e d as w e l l to o b t a i n as much data as p o s s i b l e . The annual game r e p o r t s of the Royal Canadian Mounted P o l i c e detachments and w r i t t e n or o r a l r e p o r t s by personnel of Federal Government Departments, the U. S. F i s h and W i l d l i f e S e r v i c e , the Hudson's Bay Company, the Roman C a t h o l i c missions, bush p i l o t s and Eskimos have a l l been compiled to present muskox d i s t r i b u t i o n s as a c c u r a t e l y as p o s s i b l e w i t h i n the l i m i t a t i o n s of the data. The raw i n f o r m a t i o n i s i n the f i l e s of the Canadian W i l d l i f e S e r v i c e . P r a c t i c a l l y a l l the records were acquired between 1951 and 1955, but some unusual records r e c e i v e d before and a f t e r t h a t p e r i o d add s i g n i f i c a n t l y to the t o t a l knowledge of muskox d i s t r i -b u t i o n . The observations were made c h i e f l y during s p r i n g , summer and autumn months when the animals were on w i n t e r and summer ranges. D u p l i c a t i o n of records has been avoided as c a r e f u l l y as p o s s i b l e . A d d i t i o n a l data were obtained through a number of a e r i a l and ground surveys c a r r i e d out by the author i n the years 1951, '52, •55, T56, '57 and '58. Information of p a r t i c u l a r importance obtained from other i n d i v i d u a l s has been c r e d i t e d i n the body of t h i s t h e s i s where p e r t i n e n t . A e r i a l surveys by me were conducted i n a number of d i f f e r e n t types of a i r c r a f t . Dates, areas, the number of hours and the number of m i l e s flown are given i n Table I below. Table I A e r i a l Muskox Survey Dates, Areas and Hours Flown, A r c t i c Mainland and I s l a n d s  No. of No. of M i l e s Date Area Hours Flown Flown March 1-18, 1951 Bathurst I n l e t - T h e l o n 27 2700 March 12-19, 1952 Thelon Game Sanctuary ( p a r t j 1$ 1800 A p r i l 2-5, 1955 " " " " 1 3 1500 March 23,25,26, 1956 " " n " 10 1000 March 16-24, 1957 Wager Bay-Simpson Lake 37 3700 August 10, 1958 Lake Hazen, Ellesmere I s l . 3 300 August 2,4, 1959 w " I ^ 6 540 114 11,540 A l l a i r c r a f t were single-engined high-winged monoplanes and i n c l u d e d the Belanca S k y r o c k e t , t t h e De H a v i l l a n d Beaver and the De H a v i l l a n d O t t e r . F l i g h t s v a r i e d between 500 and 1000 f e e t above ground, although the 500 f o o t l e v e l was u s u a l l y maintained and airspeeds averaged about 100 miles per hour. Observations were recorded as the animals were seen and t h e i r l o c a t i o n s p l o t t e d on maps. Survey routes were predetermined, the t r a n s e c t s i n some cases l y i n g p a r a l l e l to each other. I n other cases the most ef-f i c i e n t use of the money a v a i l a b l e could be made by f l y i n g over - 6 -areas where muskoxen were believed to exist. The map, Figure 2, gives the routes of the aerial surveys made on the Canadian mainland since 1951. Biological Data Four major ground studies were carried out to gather bio-logical information. The f i r s t study pertinent to this thesis was conducted i n the Thelon Game Sanctuary from July 6 to August 19, 1952. Transportation to the area was by bush aircraft and within i t , by canoe, some 250 miles of river being travelled. The second study was again i n the Thelon Game Sanctuary from March 26 to April 29, 1956. As winter conditions prevailed, a dog team was used to cover 500 miles of muskox winter range. The third investigation, from July 20 to August 12, 1957, was carried out i n one locale i n the Thelon with most of the work being done on foot. The fourth and f i n a l study was i n the Lake Hazen, Ellesmere island region and was conducted between May 30 and August 20, 1958. Field work was done largely by back-packing supplies to study sites. Specific objectives were formulated for each of the ground studies, and the method appropriate to each followed. Those objectives, with their methods are outlined below. Environmental Facts. The physical environment of an animal has profound influences on i t s occurrence, survival and increase. An examination of the environment of muskoxen i s essential before an understanding i s achieved of how the animal i s able to exist under the harsh - 7 -c o n d i t i o n s of the A r c t i c . For t h a t reason a number of environ-mental c h a r a c t e r i s t i c s of muskox ranges were examined. D e s c r i p t i o n s of muskox ranges are made from d i r e c t observa-t i o n s and from the l i t e r a t u r e . Topographical and g e o l o g i c a l i n f o r m a t i o n was obtained from f e d e r a l government survey r e p o r t s . C l i m a t i c c o n d i t i o n s i n many A r c t i c regions have been reported f o r a number of years by the M e t e o r o l o g i c a l D i v i s i o n of the Department of Transport and i t i s t h e i r records, plus my own f i e l d r e c ords, which are used i n t h i s paper. Range Studies Food i s one of the b a s i c l i f e requirements of a l l animals. I n the case of muskoxen, an examination of the vegetation' on known summer and winter ranges to determine the occurrence, d e n s i t y , p r o d u c t i v i t y and n u t r i t i o n a l value of p l a n t species would help to d e f i n e t h e i r a v a i l a b i l i t y and value as w e l l as serve as a b a s i s of comparison w i t h f i n d i n g s of s i m i l a r s t u d i e s c a r r i e d out on food species of game animals of temperate r e g i o n s . Two areas were examined, s e l e c t e d small p o r t i o n s of w i n t e r and summer range of the Thelon Game Sanctuary i n 1957 and a p o r t i o n pf the w i n t e r and summer range a t Lake Hazen i n 1958. i n the two areas, w i t h the exception of the Thelon summer range s i t e s , the Clarke (1942J P o i n t Sample method was employed to determine the frequency of occurrence of p l a n t species and square quadrats were u t i l i z e d to assess the degree of cover provided by the s p e c i e s . The i n t e n s i t i e s of the range s t u d i e s were based on the recommend-a t i o n given by Brown (1954). - 8 -In the s t u d i e s conducted i n the Thelon Games Sanctuary and at Lake Hazen food produced per acre of range was assessed, p l a n t s were c o l l e c t e d f o r n u t r i t i o n a l analyses, and a few s o i l samples were c o l l e c t e d f o r mineral analyses. F i n a l p l a n t i n d e n t i f i c a t i o n i n a l l cases was by Dr. A. E. P o r s i l d , N a t i o n a l Herbarium of Canada. During the 1956 winter s t u d i e s i n the Thelon Game Sanctuary, eight species of p l a n t s known to be muskox w i n t e r food were c o l l e c t e d f o r n u t r i t i o n a l analyses. Two l i c h e n species a l s o were c o l l e c t e d as i t was observed the animals were consuming them when the l i c h e n s were entangled i n the p r o s t r a t e branches of the shrubs. The l o c a t i o n s of the 1957 Thelon range surveys are i n d i c a t e d on Fig u r e 3. Two summer fe e d i n g areas, range I and range I I , were examined. The f i r s t was a w i l l o w f l a t on the north shore of the Thelon R i v e r , a t 64° 17rN, 102° 41'W. The second was on the same side of the r i v e r a t i t s i n t e r s e c t i o n w i t h 102° 39!W. Muskoxen had been observed to feed i n both areas, p a r t i c u l a r l y i n the f i r s t where herds and s o l i t a r y b u l l s were seen i n 1952, 1955 and 1957 by the author. S i x t y p l o t s , each one-square metre i n area, were examined on range'I. The p l o t s were at f i f t y yard i n t e r v a l s on one of two t r a n -sects which ran p a r a l l e l to the shore of the r i v e r . Each species of p l a n t o c c u r i n g w i t h i n the p l o t s was r a t e d f o r the percentage of area i t covered i n the square metre, but as i t was not p o s s i b l e to use the Cl a r k e method to determine frequency of occurrence of the p l a n t s i n the t o t a l p l a n t occurrence, the frequency w i t h which each species was found i n the 29 p l o t s was c a l c u l a t e d . 'Map o f t h e T h e l o n Game S a n c t u a r y , N . W . T , L o c a t i o n s o f h e r d s s i g h t e d f r o m t h e a i r and o f t h e 1957 r a n g e -•"i s t u d i e s a r e g i v e n . »1953 and 1955 w i n t e r o b s e r v a t i o n s *195k and 1955 summer o b s e r v a t i o n s •1956 w i n t e r o b s e r v a t i o n s • sumr er range s i t e s • w i n t e r range s i t e s S c a l e i s 16 m i l e s t o t h e i n c h . 103* i n ? ' - 9 -- 10 -Ten, one-square metre p l o t s a t one hundred yard i n t e r v a l s were then c l i p p e d of a l l the 1957 production of f o l i a g e . The f o l i a g e was then a i r - d r i e d and weighed. F o l i a g e from each of the important p l a n t species i n the p l o t s was c o l l e c t e d and a i r - d r i e d . The same pro-cedure was f o l l o w e d on range II, except that annual f o l i a g e pro-d u c t i o n was not determined. Twenty-five p l o t s were examined i n two t r a n s e c t s a t t h a t l o c a t i o n . The two winter areas s e l e c t e d f o r study were near the f i r s t s i t e s e l e c t e d f o r summer range s t u d i e s , and are marked on F i g u r e 3 a l s o . Range III was on a s l i g h t l y r o l l i n g s e c t i o n of the tundra north of the Thelon. Range IV was on a long r i d g e three m i l e s north-east of range I. Winter dung of muskox was present on both ranges and 16 of the animals were seen near range III on March 23, 1956. On range III, 100 throws of the Clarke P o i n t sample were made at 50 yard i n t e r v a l s g i v i n g 1000 p o i n t s upon which to determine p l a n t species composition and frequency. One hundred p l o t s , a l s o a t 50 yard i n t e r v a l s , were examined f o r species d e n s i t y . Each p l o t was 30 cm. square. The year's growth of each important p l a n t species o c c u r r i n g i n the p l o t s was c o l l e c t e d and a i r - d r i e d . Twenty p l o t s were c l i p p e d of the years growth, a i r - d r i e d and weighed. A s o i l sample was taken. On range IV, 75 throws, or 750 p o i n t s were made and 50 p l o t s were examined f o r p l a n t d e n s i t y . The p l a n t species and a s o i l sample were c o l l e c t e d f o r analyses as above, except t h a t only 10 p l o t s were c l i p p e d f o r forage production. 11 -The l o c a t i o n s of the Lake Hazen range surveys are given i n F i g u r e 4. The summer range s t u d i e s were done on two, adjacent, but e c o l o g i c a l l y q u i t e d i f f e r e n t areas. D e s c r i p t i o n s of the * areas are given i n the s e c t i o n on r e s u l t s . On range I , 100 throws of the Clarke P o i n t sampler were made, each throw being at 25 yard i n t e r v a l s , along two t r a n s e c t s which were 100 yards apart and which r a n up and down the slope of the h i l l where the survey s i t e s were l o c a t e d . P l a n t area-coverage f i g u r e s were obtained by a s s e s s i n g 50 one-half square metre p l o t s at 25 yard i n t e r v a l s , along the same t r a n s e c t s as above. On range I I , 50 throws or 500 p o i n t s , of the C l a r k e P o i n t sampler were c a r r i e d out as above, along one tr a n s e c t which b i s e c t e d the w i l l o w zone. P l a n t area coverage was determined from 50 one-half square metre p l o t s . P l a n t production f i g u r e s were obtained by c l i p p i n g the seasons growth of w i l l o w ( S a l i x a r c t i c a P a l l . ) from 20 one-half square metre quadrats on the s i t e . The w i n t e r range s t u d i e s were c a r r i e d out i n s i m i l a r manner; two areas were s e l e c t e d at the f o o t of Mount Ubyssey, one a t the 1480 f o o t l e v e l , the other at 1680 f e e t , and the t h i r d was on an outwash d e l t a between the mouths of two r i v e r s , the Abbe and the Snow Goose. On ranges I I I and IV, 500 p o i n t s were taken i n each and on range V, on the d e l t a , 480 p o i n t s were recorded. P l a n t area coverage i n ranges I I I and IV was determined by examining 50 quadrats i n each, as i n the summer range surveys. P l a n t product-i o n was assessed by c l i p p i n g 20 quadrats on range I I I , a i r d r y i n g the m a t e r i a l , and weighing i t . On both areas the important p l a n t species were c o l l e c t e d and d r i e d f o r n u t r i t i o n a l and mineral - 12 -e v a l u a t i o n . A sample of s o i l was obtained from each area a l s o . On range I V , 48 p l o t s were examined f o r p l a n t coverage. A l l p l a n t specimens c o l l e c t e d f o r n u t r i t i o n a l analyses were sent to Dr. ft. B. Carson, Head, Chemistry U n i t , Department of A g r i c u l t u r e , Ottawa, where percentage compositions on a dry matter b a s i s were determined. A l l s o i l samples were sent to Dr, H. J . Atkinson, head of the S o i l Chemistry Unit of the Chemistry D i v i s i o n , Science S e r v i c e , Department of A g r i c u l t u r e , Ottawa. Standard s o i l analyses were made. Po p u l a t i o n and P h y s i o l o g i c a l Studies The analyses of the p o p u l a t i o n s t r u c t u r e of a species i n a given r e g i o n may r e v e a l a number of important p o p u l a t i o n charact-e r i s t i c s , such as d i f f e r e n c e s i n behaviour among age and sex c l a s s e s , production of c a l v e s , s u r v i v a l of d i f f e r e n t age c l a s s e s and the trend i n numbers of the species i n a r e g i o n . I f the data are s u f f i c i e n t , l i f e t a b l e s can be constructed, i n f o r m a t i o n about the above p o i n t s i s e s s e n t i a l f o r an understanding of muskox l i v e -l i h o o d i n the A r c t i c and so part of the current study was d i r e c t e d to that end, i n f o r m a t i o n on times of r u t and c a l v i n g was obtained from d i r e c t o b s e r v a t i o n , as were p o p u l a t i o n f i g u r e s . I n the l a t t e r case, because of the d i s t a n c e of the animals from the observer, i t was p o s s i b l e i n many instances to i n d i c a t e only calves and others, the l a t t e r category i n c l u d i n g male and female a d u l t s and immatures. Secondary sex d i f f e r e n c e s between male and female a d u l t s have been described i n an e a r l i e r paper (Tener, 1 9 5 4 ) , but f o r purposes - 13 -here i t i s s u f f i c i e n t to say t h a t f i e l d r e c o g n i t i o n i s r e l a t i v e l y easy, provided one i s near the animals; the more massive horns of the males w i t h a heavy boss a t the base of each horn almost u n i t -i n g at the centre of the s k u l l , serves to i d e n t i f y t h a t sex. A d u l t cow horns are more slender and are separated a t the base by h a i r , the width of which v a r i e s i n d i v i d u a l l y , but which g r e a t l y exceeds t h a t of the b u l l s . immature animals were d i s t i n g u i s h e d by incomplete horn d e v e l -opment and s m a l l body s i z e . A l l e n ' s (1913) d e s c r i p t i o n of horn development was used as a guide i n determining age and sex a l -though complete r e l i a b i l i t y cannot be placed on f i e l d i d e n t i f i c a -t i o n when u s i n g h i s r a t h e r s u b j e c t i v e c r i t e r i a . x e a r l i n g s of both sexes have small s t r a i g h t horns, p r o t r u d i n g j u s t beyond the h a i r of the head. Calves were e a s i l y i d e n t i f i e d . A l l m o r t a l i t y data were deri v e d from records of other observ-ers or by i n f e r e n c e from carcasses I examined. The f i r s t and second r i g h t upper molar t e e t h were c o l l e c t e d from 189 muskox s k u l l s found at Lake Hazen. By s e c t i o n i n g each to o t h and by attempting to work out a s a t i s f a c t o r y counting technique, i t was hoped that i t would be p o s s i b l e to count annual growth r i n g s and so to age the animals f o r the determination of a g e - s p e c i f i c m o r t a l -i t y r a t e s . P h y s i o l o g i c a l data were c o l l e c t e d as opportunity permitted because there are no such data a v a i l a b l e i n the l i t e r a t u r e and because i t was hoped th a t i n f o r m a t i o n would be obtained which might shed l i g h t on the animals a b i l i t y t o e x i s t i n the A r c t i c . Blood from three b u l l s shot i n August, 1957, i n the Thelon Game - 14 -Sanctuary, was analysed for minerals and corticoids. The blood samples were obtained by puncturing the jugular of each animal immediately after i t was shot and allowing the blood to flow into vials containing sodium fluoride. The vials were stoppered and cooled immediately and eventually flown to the University of British Columbia, where Dr. A a-r.ra.ete undertook the appropriate procedures of the analyses. Samples of back fat were obtained from an adult cow muskox collected April 22, 1956, i n the Thelon Game Sanctuary, and were sent to Dr. C.Y. Hopkins of the National Research Council for total composition analysis of the various fat components. For procedures involved the reader i s referred to Chisholm and Hopkins (1957). A sample of 76 grams of milk was collected from the above cow immediately after i t s death. The milk was put into a plastic bot-t l e and preserved with corrosive sublimate. The sample then froze and became curdled after thawing but did not sour. The milk was analyzed by Dr. R. R. Riel, Chemistry Division, Science Service, Department of Agriculture, Ottawa, and a vitamin B12 determination was made by Dr. J. A. Campbell, Food and Drug Directorate, Department of National Health and Welfare, Ottawa. Fat and total solids were determined by the Mojonnier method. Proteins and non-acid precipitable proteins were determined by the semimicro-Kjeldahl method. Lactose was estimated by the anthrone method, except that the developed colour was measured at 620 jx with a Beckman Model DU spectrophotometer, and ash was determined according to the A. 0. A. C. method. - 15 -Rumen j u i c e s were procured from three a d u l t b u l l s shot August 5th, 7th and 11th, 1957, i n the Thelon Game Sanctuary, and from two a d u l t b u l l s shot J u l y 18th and August 5th, 1958, at Lake Hazen. The samples were preserved i n 50 per cent a l c o h o l and sent t o Dr. 1. Lubinsky, I n s t i t u t e of P a r a s i t o l o g y , Macdonald C o l l e g e , Quebec, f o r c i l i a t e i d e n t i f i c a t i o n . The h e a r t s , lungs, l i v e r s , spleens and kidneys of s i x b u l l s were weighed to the nearest one-tenth of a pound, c h i e f l y because the weights of muskox organs had not been recorded p r e v i o u s l y , but a l s o to o b t a i n a measure of the species metabolic machinery f o r f u t u r e p h y s i o l o g i c a l use. Rumen and colon contents were c o l l e c t e d from each of three b u l l s shot i n 1957 i n the Thelon. The r e s u l t i n g m a t e r i a l from each animal was a i r - d r i e d immediately a f t e r i t s c o l l e c t i o n and then s t o r e d i n p l a s t i c bags u n t i l bomb c a l o r i m e t r i c t e s t s were done a t the U n i v e r s i t y of B r i t i s h Columbia. The r e s u l t s of those t e s t s have not yet been made a v a i l a b l e . Pathology Procedures Very l i t t l e was known of the pathology of muskoxen. The low r a t e of i n c r e a s e of t h e i r t o t a l p o p u l a t i o n warranted examination of specimens to see i f l e t h a l pathogens e x i s t e d which might r e s u l t i n heavy m o r t a l i t y . Thorough post-mortem examinations of muskoxen were undertaken on the three b u l l s c o l l e c t e d i n 1957 w i t h i n ten miles of each other i n the Thelon Game Sanctuary. Dr. Harold C. Gibbs, then w i l d l i f e p a t h o l o g i s t w i t h the Canadian w i l d l i f e S e r v i c e , and 1, undertook systematic examination of the carcasses immediately a f t e r the death of the animals. - 16 -A l l three b u l l s were shot near running water, f a c i l i t a t i n g post-mortem procedures. The r e s p i r a t o r y and d i g e s t i v e systems were examined and the contents of the i n t e s t i n e s were washed through sieves to c o l l e c t such p a r a s i t e s as were present. Nema-todes and cestodes found were preserved i n 10 per cent f o r m a l i n and shipped t o Ottawa f o r i d e n t i f i c a t i o n . Whole blood from one muskox was preserved i n sodium f l u o r i d e and sent to Dr. Robert C o n n e l l , V e t e r i n a r y Research L a b o r a t o r i e s , Lethbridge, A l t a . , f o r b r u c e l l o s i s examination. Two a d u l t cows c o l l e c t e d on Thelon w i n t e r range i n A p r i l , 1956 were examined by the w r i t e r , as were three a d u l t b u l l s shot a t Lake Hazen i n 1958. The p a r a s i t o l o g i c a l examinations were not as d e t a i l e d as those above, p a r t l y because of the inexperience of the w r i t e r and p a r t l y because of t e c h n i c a l d i f f i c u l t i e s . Behaviour Studies The behaviour of an animal i s i n t i m a t e l y r e l a t e d to i t s e x i s -tence i n any area. Apart from the s c i e n t i f i c value, per s&, of knowing how an animal r e a c t s to v a r i o u s s i t u a t i o n s i t encounters dur i n g i t s l i f e , behaviour s t u d i e s may shed l i g h t on how the species i s a ble to l i v e s u c c e s s f u l l y i n i t s environment. Frequently phylo-gen e t i c r e l a t i o n s h i p s are discovered as w e l l . The behaviour of muskoxen i n d i f f e r e n t s i t u a t i o n s was recorded as o p p o r t u n i t y permitted throughout the study. Periods of observ-a t i o n of undisturbed animals v a r i e d i n le n g t h from a few minutes to seven hours. P a r t i c u l a r a t t e n t i o n was d i r e c t e d to r e p r o d u c t i v e and group behaviour. - 17 -RESULTS Environmental C h a r a c t e r i s t i c s  Climate The r e g i o n i n h a b i t e d by most Canadian muskoxen i s c h a r a c t e r -i z e d by what Dansereau (1957) c a l l s a g l a c i a l c l i m a t e , one i n which the average temperatures of the warmest months are below 10° C. (50°F.). P o r s i l d (1957) uses the same isotherm to def i n e the term Canadian A r c t i c f o r f l o r i s t i c purposes. That isotherm, as depicted on Chart 1-5 of the A t l a s by Thomas (1953), runs from A k l a v i k , near the mouth of Mackenzie R i v e r , east t o Coppermine and Bathurst i n l e t , thence s o u t h e a s t e r l y across Beverly Lake on the Thelon R i v e r drainage to cross the west coast of Hudson Bay at about Eskimo P o i n t . The south-eastern d e f l e c t i o n of the i s o -therm i s a t t r i b u t e d by P o r s i l d (op. c i t . ) to the i n f l u e n c e of the co l d waters of Hudson Bay. Many of the mainland muskoxen l i v e south of the 50° isotherm, however, p a r t i c u l a r l y those i n the Thelon Game Sanctuary, the Bathurst i n l e t area and the land between, but t h e i r d i s t r i b u t i o n does not reach south to the 55°F isotherm. The g l a c i a l c l i m a t e i n f l u e n c e s an area of about 1,000,000 square miles or 900,000 square miles of land, of which the A r c t i c Archipelago c o n t r i b u t e s 549,000 square miles and the A r c t i c main-land the r e s t . The cl i m a t e i s one of sho r t , c o o l summers, lo n g , c o l d w i n t e r s and r e l a t i v e l y l i t t l e p r e c i p i t a t i o n . Some of the c l i m a t i c c h a r a c t e r i s t i c s of northern Ellesmere i s l a n d and the Thelon Game Sanctuary r e s p e c t i v e l y , are i n d i c a t e d i n Table I I . Two f a c t s become apparent immediately upon comparison of the data - l S -i n the t a b l e . One i s t h a t the mean minimum temperatures and the mean annual s n o w f a l l and maximum snow depth are very s i m i l a r i n values. The second i s t h a t important d i f f e r e n c e s e x i s t i n annual p r e c i p i t a t i o n and the mean annual l e n g t h of the growing season, defined as days w i t h temperatures of 42°F. or greater (Anonymous, 1957). The Thelon area experiences twice the annual p r e c i p i t a t i o n and twice the growing season l e n g t h of Ellesmere I s l a n d . Snowfall i n many A r c t i c regions i s u s u a l l y much l e s s than i n southern Canada. The average annual f a l l a t Resolute Bay, Corn-w a l l i s I s l a n d , f o r example i s 30.12 inches; at Isaachsen, E l l e f Ringnes I s l a n d , 19.7 inches; Mould Bay, P r i n c e P a t r i c k I s l a n d , 20.0 inches; and at Eureka, Ellesmere i s l a n d , 15.4 i n c h e s . On the A r c t i c mainland a t Baker Lake the annual average s n o w f a l l i s 21.9 i n c h e s . Muskoxen l i v e near a l l of those s t a t i o n s . By comparison, s n o w f a l l values i n A l b e r t a and Saskatchewan, f o r example, averaged between 33 and 75 inches a n n u a l l y (Dept. of Transport, 1954). The mean annual maximum snow depth i s 10 to 20 inches, which i s , as discussed l a t e r , an important f a c t o r i n muskox fe e d i n g h a b i t s . The d i s t r i b u t i o n of the annual p r e c i p i t a t i o n , i n d i c a t e d i n Table I I I , i s not uniform i n a l l seasons. About two inches f a l l i n summer and autumn seasons on both northern Ellesmere and on the Thelon r e g i o n . G e n e r a l l y the s p r i n g and w i n t e r p r e c i p i t a t i o n i s l i g h t , p a r t i c u l a r l y on northern Ellesmere where one i n c h or l e s s f a l l s . P o r s i l d (op. c i t . ) p o i n t s out t h a t the mean annual p r e c i p i t a -t i o n i s so low t h a t were i t not f o r the p e r p e t u a l l y f r o z e n ground (permafrost) found c l o s e to the s u r f a c e , l a r g e areas i n the A r c t i c Archipelago would be e n t i r e l y without v a s c u l a r p l a n t s . - 19 The melt season on the A r c t i c mainland begins i n the l a t t e r p a r t of May and snow i s u s u a l l y gone, except f o r d r i f t e d areas, by the middle of June* On the Archipelago m e l t i n g u s u a l l y s t a r t s e a r l y i n June and i s over i n about two weeks time. The combina-t i o n of a b l a t i o n and r u n - o f f r e s u l t s i n a r a p i d disappearance of snow. R i v e r s are u s u a l l y running by the end of June throughout the A r c t i c . Smaller l a k e s are f r e e of i c e e a r l y i n J u l y on the mainland but l a r g e r l a k e s may r e t a i n some i c e u n t i l August. On the Archipelago, l a k e s u s u a l l y are f r e e of some, i f not a l l of t h e i r i c e , by the f i r s t of August, but the l a r g e r l a k e s , such as Lake Hazen, may be p a r t l y i c e covered throughout the summer months. Another f a c t o r of importance, not given i n the t a b l e , i s the l i g h t regimen d i f f e r e n c e . I n the Thelon Game Sanctuary, which i s south of the A r c t i c C i r c l e , there i s a p e r i o d of about two hours when the sun i s below the h o r i z o n on the longest day of the year, June 21st, and a p e r i o d of three and one h a l f hours of sunshine on the s h o r t e s t day of the year, December 22nd. Fosheim Peninsula and Lake Hazen, two areas on northern Ellesmere I s l a n d where muskoxen have been s t u d i e d , r e c e i v e twenty f o u r hours of s u n l i g h t from about A p r i l 15th to the end of August each year, and no s u n l i g h t from about October 20th to March 1 s t . During the depths of w i n t e r , h i g h A r c t i c animals i n c l u d i n g musk-oxen, must c a r r y on t h e i r d a i l y f u n c t i o n s i n darkness or near dark-ness. * 20 -Table I I Climate Comparisons of the Thelon Game Sanctuary and Northern Ellesmere I s l a n d Temperature i n °F P r e c i p i t a t i o n Thelon Game N. Ellesmere Thelon Game N. Ellesmere Charact- Sanctuary i s l a n d Charact- Sanctuary I s l a n d e r i s t i c e r i s t i c Jan. mean Mean d a i l y -30° -30 to-35° annual 8" 4" t o t a l J u l y mean d a i l y 50 to 55° 40 to 45° Mean 30" 30" annual or or Mean annua] s n o w f a l l l e s s l e s s min. -50° -50° Mean date Mean annua] of 1st max. 70 to 80° 60 to 70° snow cover Oct. 7 Sept. 7 of 1" or Mean annua] 80 to 100 40 days or plus l e n g t h of days l e s s growing Mean an-season nual No. days w i t h 240 280 + snow cover of 1" or plus Mean date l a s t snow June 9 - June 29 cover 1" 19 or p l u s Mean an-nual max. 10 - 20" 10 - 20" snow depth - 21 -Table I I I Annual P r e c i p i t a t i o n D i s t r i b u t i o n Thelon Area Northern Ellesmere i s l a n d Mean Spring Ppt.(March-May) 1" 1" Mean Summer Ppt.(June-Aug.) 2"-4" 2" Mean Autumn Ppt.(Sept.-Nov.) 2" l " - 2 " Mean Winter Ppt.(Dec.-Feb.) l " - 2 " l e s s than 1" - 22 -Topography of Muskox Ranges The d i s t r i b u t i o n of muskoxen on the A r c t i c mainland of Canada i s almost completely w i t h i n the Canadian S h i e l d except f o r the few animals i n the Bluenose Lake area south of Paulatuk on the A r c t i c coast. The S h i e l d i s a r e g i o n of comparatively low r e l i e f , r i s i n g g r a d u a l l y from the A r c t i c Ocean on the north and from Hudson Bay on the east to an e l e v a t i o n of about 1,500 f e e t i n i t s c e n t r a l p a r t east of Great Bear and Great Slave Lakes. P a r t of the area i s hummocky, c o n s i s t i n g of r i d g e s and h i l l s separated by depressions occupied by l a k e s or wet tundra, and part i s of d r i e r , sandy or rocky p l a i n s . There are many lakes and r i v e r s , some of the l a t t e r being s e v e r a l hundreds of miles i n l e n g t h . For most of the area, the l o c a l r e l i e f i s r a r e l y more than 100 f e e t , but i n places east of Great Bear Lake, i t i s more than 1,000 f e e t . (Anonymous, 1951). The Canadian S h i e l d extends northward i n t o the A r c t i c A r c h i -pelago, forming p a r t s of V i c t o r i a i s l a n d , Boothia P e n i n s u l a , east Devon I s l a n d and south-east Ellesmere I s l a n d . Much of the A r c h i -pelago i s formed of lowlands and plateaus, p a r t i c u l a r l y the sou-thern i s l a n d s and those west of Devon and Axel Heiberg I s l a n d s . An extensive range of mountains runs i n a north-south d i r e c t i o n across Ellesmere, Axel Heiberg, Devon and B a f f i n I s l a n d s . The range exceeds 8,000 f e e t i n a l t i t u d e on northern Ellesmere, and, as P o r s i l d (op. c i t . ) p o i n t s out, s t r n n g l y a f f e c t s the climate of the r e s t of the Archipelago, because i t acts as a mechanical b a r r i e r f o r the f r e e f l o w of a i r from one side to the other. Muskoxen - 23 -e x i s t on a l l of the l a r g e r i s l a n d s of the Archipelago, w i t h the exception of B a f f i n I s l a n d . Summer ranges of muskoxen on the mainland are l a r g e l y centred around water sources, such as r i v e r s , ponds and l a k e s . Such areas favour vegetation growth, p a r t i c u l a r l y of w i l l o w , probably the most important summer food of the animals. The t e r r a i n along the r i v e r s , such as the Thelon, i s e a s i l y t r a v e r s e d i n most areas, p e r m i t t i n g r e l a t i v e l y u n r e s t r i c t e d movement up or down r i v e r . On the A r c t i c i s l a n d s , the animals u s u a l l y may be found near streams or seepage meadows or near ponds and lakes although t o a l e s s e r extent near water than the mainland p o p u l a t i o n . The t e r r a i n over which the animals move v a r i e s from f l a t p l a i n s , to outwash d e l t a s , to h i l l s and, i n northern Ellesmere, to mountains.. i n w i n t e r , on both the A r c t i c mainland and on the i s l a n d s , muskoxen ranges are g e n t l y r o l l i n g h i l l s , slopes or plateaus or wherever s u i t a b l e forage e x i s t s and the snow depth i s kept at a minimum by p r e v a i l i n g winds. Such winter feeding areas are not long d i s t a n c e s from summer ranges. The map, Fi g u r e 3 , i l l u s t r a t e s t h a t i n the Thelon Game Sanctuary, f o r example, w i n t e r i n g herds were w i t h i n 35 miles of t h e i r summer areas. A l l of the 192 animals seen from the a i r between March 24-28, 1 9 5 6 , i n the Thelon Game Sanctuary, were on f l a t p l a t e a u country, somwhat elevated above the surronnding t e r r a i n . Examination on the ground of two of these areas north of the Thelon R i v e r revealed contours and s h a l l -ow v a l l e y s not obvious from the a i r . The muskoxen fe d on the wind-ward slopes or on top of the low h i l l s . Depth of snow v a r i e d from two to three inches to a f o o t or more i n d r i f t s . - 24 -From evidence obtained a t Lake Hazen i n 1958, i t would appear t h a t w i n t e r and summer feeding areas may be w i t h i n l e s s than h a l f a m i l e of each other or i n some cases may be the same p l a c e . The 1959 survey, however, i n d i c a t e d t h a t muskoxen had s h i f t e d t h e i r summer ranges 30 to 50 m i l e s to the east. The t e r r a i n under study i n 1958 was d i s s e c t e d w i t h r i v e r v a l l e y s , running more or l e s s p a r a l l e l to each other as they drained meltwater coming from the g l a c i e r s to the north i n t o Lake Hazen. J o i n i n g the v a l l e y s were passes through the i n t e r v e n i n g mountains, which exceeded 3,000 f e e t i n he i g h t . Muskoxen, as w e l l as other animals such as a r c t i c hare (Lepus m o n s t r a b i l i s ) and caribou (Rangifer tarandus p e a r y i ) f e d on the long sedge, w i l l o w and moss slopes which ran down to the r i v e r s . Those passes and slopes are exposed to winds and have a shallow snow cover. Some muskox summer dung and much winter dung were present on most of the west f a c i n g , or eastern slopes of the v a l l e y s , i t was i n t e r e s t i n g to note t h a t very few muskoxen were observed on the west slope of the Snow Goose R i v e r V a l l e y , one of a number of v a l l e y s empty-i n g i n t o Lake Hazen. i n v e s t i g a t i o n r e vealed t h a t v e g e t a t i o n there was l a r g e l y moss, b e l l heather and some sedges, unimportant muskox food. S o i l Analyses The r e s u l t s of the few s o i l samples c o l l e c t e d during the present i n v e s t i g a t i o n are given i n Tables IV and V. The Thelon summer range samples were s l i g h t l y a l k a l i n e i n chara c t e r as might be expected i n w e l l drained a l l u v i a l s o i l along a r i v e r course. * 25 -Table IV Soi l Analyses Results of Samples from Thelon Game Sanctuary Date, 1957 July 23 July 30 July 31 July 31 August 3 Area: Summer Range 1 Summer Range 2 4 winter Range 1 (M) 4 Winter Range 1 to) Winter Range 2 PH 7.3 7.1 4.0 3.8 4.0 Total N {%) 0.06 0.17 0.12 0.75 0.08 1. Organic matter {%) 0.9 3.8 8.6 32.6 3.5 2. Soluble P (p.p.m.) 34.2 47.7 6.2 12.0 2.4 3. Base Exch. Capacity 3.68 9.29 7.41 33.8 3.54 Exch. Bases: C* . 2.2a 7.70 0.80 3.35 0.40 Mi ; 1.35 3.22 0.65 2.00 0.35 K 0.07 0.11 0.20 0.87 0.07 1. Wet-oxidation process 2. Bray acid-soluble + absorbed 3. m.e. per 100 gms. 4. M =» mineral s o i l sample 0 » organic s o i l sample - 26 -Both winter range areas sampled, however, were decidedly a c i d i c i n nature, pH values v a r y i n g between 3.8 and 4.0. The sample c o l l e c t e d J u l y 31 on winter range I was d i v i d e d i n t o an organic sample f o r a n a l y s i s since a l a r g e mat of organic m a t e r i a l was in c l u d e d i n the o r i g i n a l sample. Apart from an organic sample from the f i r s t winter range s i t e which gave a r e l a t i v e l y high v a l u e , t o t a l n i t r o g e n contents i n the samples were under 0.20 per cent. The percentage of organic matter v a r i e d between 0.9 f o r the summer range I sample to 32.6 f o r the sample from winter range 1. Sol u b l e phosphorous content was highest i n the two samples from the summer ranges, t h e i r values being 34.2 and 47.7 parts per m i l l i o n . Base exchange c a p a c i t i e s of the mineral s o i l samples v a r i e d between 3.54 and 9.29 per cent, and the organic sample value was 33.8 per cent. There was considerable v a r i a t i o n i n the content of the exchangeable bases of the f o u r samples, calcium values ranging between 0.40 and 7.70, magnesium between 0.35 and 3.22 and potassium between 0.07 and 0.87. Lake Hazen s o i l samples (Table V) were l e s s v a r i a b l e i n t h e i r c h a r a c t e r i s t i c s than those from the Thelon area. The samples were n e u t r a l to a l k a l i n e . T o t a l n i t r o g e n content v a r i e d between 0.11 and 0.25 per cent and organic matter ranged between 2.6 and 5.8 per cent. The so l u b l e phosphorous content of the sample from the blue grass a s s o c i a t i o n g r e a t l y exceeded the remaining samples, being 175 parts per m i l l i o n , as opposed to 21 to 49 p.p.m. The base exchange c a p a c i t y of the three summer range samples averaged about 23 per cent, almost double the ca p a c i t y of the s i n g l e winter range sample. This f a c t i s also r e f l e c t e d i n the values of the exchangeable bases, Mg and K. - 27 -Table V S o i l Analyses R e s u l t s of Samples from Lake Hazen Date, 1958 J u l y 26 August 2 J u l y 26 J u l y 29 Area Summer Range 1 Summer Range 1 Summer Range 2 Winter Range 1 pH 8.1 8.2 7.7 6.9 T o t a l N {%) 0.11 0.25 0.21 0.20 1. Organic matter [%). 2.6 5.8 5.5 4.4 2. S o l u b l e P (p.p.m.) 175 21 31 49 3. Base Exch. Capacity 21.8 23.3 24.0 12.7 3. Exch. Bases: Ca 28.6 25.0 25.9 11.3 Mg 8.6 6.0 4.1 1.6 K 1.1 1.0 0.9 0.2 1. Wet-oxidation process 2. Bray a c i d - s o l u b l e adsorbed 3. m.e. per 100 gms. - 28 -The s o i l sample data from the Thelon area and Lake Hazen are too few f o r s i g n i f i c a n t conclusions to be drawn. The data do suggest, however, t h a t s o i l s on muskox ranges a t Lake Hazen were a l k a l i n e , had a higher t o t a l n i t r o g e n content, base exchange capa-c i t y and exchangeable bases than the samples from the Thelon Game Sanctuary, The b e t t e r drainage of the Lake Hazen s o i l s would c o n t r i b u t e to higher pH values, f o r i n s p i t e of low p r e c i p i t a t i o n , there i s poor drainage of surface water over much of the A r c t i c mainland and i s l a n d s because of permafrost, c o n t r i b u t i n g to a c i d c o n d i t i o n s . The w i n t e r range s o i l samples from the Thelon area are a case i n p o i n t . The pH values from Lake Hazen samples compare f a v o u r a b l y w i t h those given by M i t c h e l l and Moss (1948) f o r s o i l s of the Canadian Great P l a i n s and the northern wooded regions whieh range from below pH 5.0 to over pH 9.0, w i t h the gr e a t e r p o r t i o n of surface horizons ranging between pH 6.0 and pH 8,0. S i g n i f i c a n c e of s o i l values i n muskox environment The supply of n i t r o g e n i n the s o i l r e g u l a t e s the a b i l i t y of the p l a n t to make the p r o t e i n s v i t a l to the formation of new pro-toplasm and hence i s v i t a l to p l a n t e x i s t e n c e . The percentages of n i t r o g e n i n the s o i l samples obtained i n the present study from the Thelon are l e s s than those found by Wyatt, Bowser and Odynsky (1939) i n a h o r i z o n of samples obtained i n southwestern A l b e r t a , where fou r t e e n loam and s i l t s o i l s averaged 0.27 per cent and 13 samples of c l a y and c l a y loams averaged 0.22 per cent n i t r o g e n . (The organic s o i l sample from the Thelon i s not considered i n t h i s comparison). I n the M i l k R i v e r s t u d i e s of Wyatt, Bowser and - 29 -Odynsky (1941), average n i t r o g e n content of 17 brown s o i l s of one area averaged 0.139 per cent and of 18 brown s o i l s i n another area the average was 0.115 per cent. The n i t r o g e n content of the Lake Hazen samples ranged between 0,11 and 0.25 per cent, being more d i r e c t l y comparable i n value to the A l b e r t a data. S o l u b l e phosphorous content of three samples of s o i l s from muskox wi n t e r ranges i n the Thelon Game Sanctuary were markedly lower i n value than the two summer range samples, p o s s i b l y because of the very a c i d nature of the winter range s o i l s . Furthermore the a v a i l a b i l i t y of such phosphorous as i s present, i s l e s s t o those p l a n t s growing on s o i l s s t r o n g l y a c i d i c , so the Thelon w i n t e r range p l a n t s would have l e s s phosphorous a v a i l a b l e to them f o r two reasons, s o i l a c i d i t y and lower phosphorous content. Gen-e r a l l y s o l u b l e phosphorous was low i n value f o r both the Thelon and Lake Hazen areas, p a r t i c u l a r l y when compared w i t h values from southwest A l b e r t a . The base-exchange p r o p e r t i e s of s o i l s i n f l u e n c e p l a n t n u t r i -t i o n and the d e s i r a b i l i t y of the s o i l as a growth medium i n a number of ways. N u t r i e n t c a t i o n s h e l d as exchangeable bases are i n a r e a d i l y a v a i l a b l e s t a t e but are not r e a d i l y leached from the s o i l s . C a t i o n exchange a c t s as a b u f f e r which hinders r a p i d changes i n n u t r i e n t l e v e l or c a t i o n balance. The base-exchange c a p a c i t i e s of the Lake Hazen samples exceeded considerably the value of the Thelon samples, except f o r the organic s o i l sample which cannot be used as an i n d i c a t i o n of s o i l values because of i t s o r i g i n . - The contents of Ca, Mg and K i n the Lake Hazen s o i l s were s i m i l a r l y higher than i n the Thelon samples, Ca p a r t i c u l a r l y , and save f o r K, were higher value than samples reported by Wyatt, 30 -Bowser and Odynsky (op. c i t . ) . A l a r g e p r o p o r t i o n of s o i l potassium i s i n primary h i g h -potassium minerals i n the s i l t and sand f r a c t i o n s . The minerals i n s o i l s of a r i d r e g i o n s , such as the high A r c t i c , are r e l a t i v e -l y unweathered and t h e r e f o r e are e f f e c t i v e s u p p l i e r s of potassium to p l a n t s . Potassium i s necessary f o r s e v e r a l b a s i c p h y s i o l o g i c a l f u n c t i o n s , i n c l u d i n g the formation of sugars and starches and t h e i r movements between d i f f e r e n t p a r t s of the p l a n t , the syn-t h e s i s of p r o t e i n s , normal c e l l d i v i s i o n and growth and neut-r a l i z a t i o n of organic a c i d s (Reitemeier, 1957). Of great import-ance to p l a n t s , and t h i s would i n c l u d e those i n the A r c t i c , i s i t s a i d i n h e l p i n g to overcome i n f l u e n c e s of adverse weather such as low s o i l moisture and low temperature, and of poor p h y s i c a l s o i l c o n d i t i o n s such as compaction and inadequate a e r a t i o n . The d i r e c t comparisons made between s o i l s of southwestern A l b e r t a and those on muskox ranges are not very meaningful because of the many v a r i a b l e s such as p r e c i p i t a t i o n , temperature, pH and a g r i c u l t u r a l p r a c t i c e s which i n f l u e n c e p l a n t growth and production. I n a d d i t i o n , the s o i l samples obtained i n the present study are of l i m i t e d value because of t h e i r s m a ll number and because samples were c o l l e c t e d o n l y i n vegetated areas. The i n f o r m a t i o n they provide, however, would suggest t e n t a t i v e l y t h a t the Lake Hazen muskox w i n t e r and summer range s o i l s compare fav o u r a b l y w i t h those of the c a t t l e country of southwestern A l b e r t a i n t h e i r c o n s t i t u e n t s . The Thelon samples were of lower value, p a r t i c u l a r l y those from the winter ranges. - 31 -P l a n t H a b i t a t s In A r c t i c r e g i o n s , as i n warmer c l i m e s , plant l i f e i s profoundly i n f l u e n c e d by the nature of the s o i l on which i t grows. P o r s i l d (op. c i t . ) has r e c e n t l y discussed s o i l and plant h a b i t a t s on the Archipelago and h i s e x c e l l e n t comments are repeated below, as they are p a r t i c u l a r l y p e r t i n e n t to an e c o l o g i c a l d e s c r i p t i o n of the muskox environment. "Throughout the Archipelago the s u b s o i l i s permanently f r o z e n , o f t e n to great depths (permafrost). The annual thaw of the s u r f a c e or a c t i v e l a y e r v a r i e s w i t h the texture and water content; i n sand and g r a v e l the a c t i v e l a y e r may be deep whereas i n wet peaty s o i l the summer thaw may penetrate only a few inches. On s l o p i n g ground, mass-wasting, i n the form of s o i l creeps, mudflows, and other types of s o l i f l u c t i o n i s common and widespread during e a r l y summer when the thawed surface l a y e r reaches a c r i t i c a l point of water s a t u r a t i o n . On l e v e l ground where the surface s o i l remains saturated because the permafrost l a y e r does not permit meltwater to escape, various forms of s o i l movement ( c o n g e l i t u r b a t i o n ) develop, causing a s o r t i n g of the s o i l i n t o curious p a t t e r n s of more or l e s s r e g u l a r stone and mud polygons. These movements r e s u l t from convection currents caused by repeated thawing and f r e e z i n g and are most a c t i v e under ex-treme A r c t i c or a l p i n e c o n d i t i o n s such as are found i n the north-ern p a r t s of the Archipelago and at high e l e v a t i o n s . A l s o , they are perhaps most prevalent i n s o i l s derived from the more r a p i d -l y weathering P a l e o z o i c rocks. Everywhere these processes are i n i m i c a l to p l a n t growth. "Everywhere wind a c t i o n a f f e c t s p l a n t growth unfavourably, not only by i t s c o o l i n g and d r y i n g e f f e c t i n summer or winter on plant stems and f o l i a g e , but a l s o by the mechanical abrasive e f f e c t of d r i f t i n g sand, and i n winter by t i n y snow c r y s t a l s , which at extreme low temperatures become very hard and g r i t t y . A o e l i a n d e p o s i t i o n of l o e s s i s a c t i v e , e s p e c i a l l y i n mountainous p a r t s of the Archipelago where the s p r i n g r u n - o f f from ice-caps and l a r g e perennating snow f i e l d s causes the formation of l a r g e erosion f a n s , shallow stream beds, and f l o o d p l a i n s from which high winds i n l a t e summer p i c k up f i n e s i l t . L o c a l l y , i n the p r o x i m i t y of i c e - c a p s , loess d e p o s i t i o n may be so r a p i d that only c e r t a i n species can s u c c e s s f u l l y cope with i t . "Thus s o l i f l u c t i o n , c o n g e l i t u r b a t i o n , and loess d e p o s i t i o n are important f e a t u r e s of the A r c t i c landscape and everywhere have a marked e f f e c t on p l a n t cover; only those species whose s u b - a e r i a l p a r t s are adaptable to s o i l movement or d e p o s i t i o n can s u c c e s s f u l l y c o l o n i z e or p e r s i s t i n h a b i t a t s where these processes are a c t i v e . * 32 Tufted species and those w i t h moderately developed tap-roots s u f f e r comparatively l i t t l e damage from s o i l movements, whereas those w i t h extensive.:, creeping rhizomes or stems are p a r t i c u l a r -l y , v u l n e r a b l e , "The monotonous topography of l a r g e p a r t s of the A r c t i c Archipelago and i t s u n i f o r m l y c o l d dry clim a t e are r e f l e c t e d i n the general appearance of the p l a n t cover which shows l i t t l e v a r i a t i o n from place t o p l a c e . This i s p a r t i c u l a r l y t r u e of the western i s l a n d s , whereas i n the east the mountainous topography provides more l o c a l v a r i e t y and more d i v e r s i f i e d p l a n t h a b i t a t s . "Closed v e g e t a t i o n i s nowhere extensive and occurs c h i e f l y on s h e l t e r e d slopes and i n depressions where a r e g u l a r but not too deep snow cover i s provided i n w i n t e r ; only i n the i n t e r i o r of Banks and V i c t o r i a i s l a n d s (and i n the mainland) are extensive tundra areas found. "Because of the c o l d c l i m a t e , the short summer, and con-sequent low s o i l temperatures, A r c t i c s o i l s are s t e r i l e . V e g etation everywhere i s sparse, dwarfed, and st a r v e d . Organic decay by b a c t e r i a l a c t i o n i s g r e a t l y reduced; consequently n i t r a t e s , phosphates, and other s a l t s needed by p l a n t s are d e f i c i e n t . Where these n u t r i e n t s are present, A r c t i c p l a n t s respond by l u s h and l u x u r i a n t growth. Thus, b i r d c l i f f s , animal burrows, meadows, owl perches and goose n e s t i n g grounds, or places near present or past human h a b i t a t i o n , or even near animal dung or s k e l e t a l remains are o f t e n marked from a f a r by l u s h and green v e g e t a t i o n i n s t r i k i n g c o n t r a s t to otherwise drab and grey A r c t i c landscape". The e c o l o g i c a l r e l a t i o n s h i p between p l a n t abundance and musk-ox dung on muskox ranges near A l e r t , Ellesmere I s l a n d , has been discussed by L a v e r d i e r r e (1954), i t was h i s t h e s i s t h a t constant use of an area by the animals produced r i c h e r p l a n t growth. The present w r i t e r has observed a l s o on many occasions the r i c h e r p l a n t growth r e s u l t i n g from decaying animal matter. Range Vegetation Thelon Game Sanctuary I t has already been pointed out i n the d i s c u s s i o n of muskox fe e d i n g h a b i t s that i n summer i n the Thelon Game Sanctuary, herds and s o l i t a r y b u l l s are u s u a l l y found f e e d i n g along the banks of the main r i v e r or i t s t r i b u t a r i e s . Dense t h i c k e t s of w i l l o w of - 33 s e v e r a l s p e c i e s , sometimes on low i s l a n d s or on the s i l t e d shores of the r i v e r s , are s c a t t e r e d along the Thelon system, but p r i n c i p a l l y between the Grassy I s l a n d area and the F i n n i e R i v e r (Figure 3 ) . Clumps of stunted black spruce ( P i c e a mariana ( M i l l . ) B.S.P.) f r i n g e the Thelon from the southern boundary of the Sanctuary to beyond the F i n n i e R i v e r , and f o r the most p a r t l i e between the shore v e g e t a t i o n and the tundra which extends e i t h e r s i d e of the r i v e r . The v e g e t a t i o n a l composition of the t h i c k e t s v a r i e s c o n s i d e r a b l y from almost pure stands of one species of w i l l o w to s e v e r a l species and may i n c l u d e as w e l l b i r c h , sedges, grasses and f o r b s . The summer feeding area along the Thelon R i v e r i s at l e a s t 100 miles i n le n g t h and i t was p h y s i c a l l y impossible t o o b t a i n a s t a t i s t i c a l l y s i g n i f i c a n t sample of the feeding s i t e s f o r v e g e t a t i o n a l e v a l u a t i o n . The two areas chosen f o r v e g e t a t i o n a l a n a l y s i s cannot, t h e r e -f o r e , be considered as being wholly r e p r e s e n t a t i v e of the summer feed i n g s i t e s of muskoxen. Both areas, however, as st a t e d e a r l i e r i n t h i s paper, have been used by the animals f o r a number of years and f o r t h i s reason were s e l e c t e d f o r analyses. The frequency of occurrence i n the p l o t s of,.and the area of ground covered by, the p l a n t species recorded on the summer range s i t e s I and I I are given i n Table V I . - 34 -Table ¥ 1 Thelon Game Sanctuary-Summer Ranges, I and I I P l a n t Species Occurrence Frequency and Area Coverage i n per cent Species Summer Ranee 1, 60 p l o t s Summer Range 11, 25 n l o t s Transect I Transect 11 P l o t s Occurred Area Covered P l o t s Occurred Area Covered P l o t s Occurred Area Covered Equisetum 0.8 arvense L. 32.7 2.8 93.3 2.0 40 Carex Bige-l o w i l T o r r . 72.4 2.0 56.7 4.7 4 0.4 Juncus species 4 0.4 Poa p a l u s t r i s 10.3 T 53.3 2.7 8 0.4 S a l i x R i c h a r d -s o n i i Hook 41.4 4.1 46.7 2.7 76 15.2 S # a l a x e n s i s (Anderss.) Cov. 93.1 24.1 86.7 22.7 52 11.6 S. a r b u s c u l o i -des Anderss, 58.6 3.4 36.7 1.3 20 2.0 S. glauca v a r . a c u t i f o l i a (Hook,) Schneid. 64 13.8 B e t u l a glandulo-sa Michx, 12 2.4 Lupinus a r c t i c u s Wats. 20 2.0 A s t r a g a l u s a l p i -nus L. 12 1.2 A r c t o s t a p h y l o s U v i - U r s i L. 12 4.4 Miscellaneous f o r b s 52 6.4 S o i l 100 62.7 100 61.3 84 34.0 ~ 35 -On the f i r s t s i t e the p r e f e r r e d w i l l o w food, S a l i x a l a x e n s i s t occurred most f r e q u e n t l y and covered the l a r g e s t area of ground, of a l l p l a n t s p e c i e s , i t should be noted, however, that bare ground composed 61.3 per cent of the t o t a l p l o t areas. The second summer range s i t e had a more d i v e r s i f i e d p l a n t cover. S a l i x a l a x e n s i s occurred i n 52 per cent of the p l o t s examined and covered 11.6 per cent of the surface area of the ground. Of the two other w i l l o w s , S a l i x R i c h a r d s o n i i and S.  glauca v a r . a c u t i f o l i a . the former species was more abundant but not markedly so. The d i f f e r e n c e s i n v e g e t a t i o n a l composition between the two s i t e s i s a t t r i b u t e d i n p a r t to t h e i r d i f f e r e n t l o c a t i o n . The f i r s t study s i t e i s flooded a n n u a l l y each s p r i n g and i s subject to the erosion of f a s t water, i c e and d e b r i s . Only deep rooted p l a n t s , or those w i t h tough stems, would s u r v i v e . The second study s i t e was along a backwater of the r i v e r and i s flooded w i t h calm water i n s p r i n g . L i t t l e e rosion occurs. Obtaining a s t a t i s t i c a l l y l a r g e enough sample of the w i n t e r f e e d i n g areas presented the same problem as f o r summer ranges. The two areas s e l e c t e d were known to be used by muskoxen, however, and appeared to have the same v e g e t a t i o n as other w i n t e r feeding s i t e s examined twenty-five miles north of the Thelon R i v e r i n March and A p r i l , 1956. The r e s u l t s of the range s t u d i e s on the two areas are given i n Table V I I . - 36 -Table V I I Thelon Game Sanctuary-Winter Range I and I I P l a n t Species Occurrence Frequency and Area Coverage i n per cent Species Winter Range I , 100 p l o t s Winter Range I I Frequw Index Area Covered Frequ. < Index 75 p l o t s Area Covered 50 p l o t s C e t r a r i a c u l c u l l a t a ( B e l l . ) Ach. 13.7 2.0 18.7 2.6 Moss 14.9 4.9 7.0 1.6 Carex rotundata .9 3.23 T .9 Carex species .8 .08 Poa species S a l i x arbusculoides Anderss. .2 .08 .03 Betula glandulosa Michx. .5 1.1 3.4 S i l e n e a c a u l i s L. va r . exscapa ( A l l . ) DC. .4 .4 .2 Rubus Chamaeorus L. .04 T Empetrum nigrum L. 3.5 2.6 2.8 3.6 Ledum decumbens L. 6.8 8.7 2.8 7.6 Andromeda P o l i f o l i a L. 5.9 6.1 2.7 2.4 Phyllodoce coerulea (L.)Bal ». .4 .4 .2 A r c t o s t a p h y l o s a l p i n a (L.) Spreng. .3 .04 .93 1.0 Vaccinium uliginosum L. .8 2.2 .93 1.7 V. V i t i s - I d a e a L. va r . minus Lodd. 14.2 3.8 12.3 3.1 l i t t e r (a) 17.8 49.57 30.0 47.6 s o i l (b) 18.6 14.7 21.5 12.2 rock (c) .5 .7 59.3 T o t a l unproductive ground 36.9 64.97 51.5 (a) + (b) + (c) - 37 -On winter range 1, the p l a n t s o c c u r r i n g most f r e q u e n t l y were moss species (14*9%) cowberry (14»2%), l i c h e n ( C e t r a r i a  c u l c u l l a t a . c h i e f l y ) (13*7%), Labrador tea (6.8%), Andromeda (Andromeda P o l i f o l i a L.j (5.9%) and crowberry (3.5%). Un-productive ground ( l i t t e r , s o i l and rock) c o n s t i t u t e d 36.9 per cent of the p o i n t s . Some food s p e c i e s , such as b i l b e r r y (0.8%), carex species (0.7%), b i r c h (0.5%) and w i l l o w (0.2%) were sparse i n occurrence. -£he most abundant p l a n t on the second winter range s i t e was l i c h e n (18.7%), f o l l o w e d by cowberry (12,3%), moss (7.0%), l a b r a d o r tea (2,8%), crowberry (2.8%) and Andromeda. (2,7%). B i l b e r r y , a f a v o u r i t e food, was .93 per cent. The frequency of unproductive ground t o t a l l e d 51.5%, Unproductive ground on both w i n t e r s i t e s c o n s t i t u t e d over h a l f of the areas sampled. On winter range 1, the f i g u r e was 64.97 per cent and on range I I i t was 59.# per cent. The area covered by muskox food p l a n t s , l a b r a d o r t e a , crowberry, the two vacciniums, b i r c h and carex on both ranges, was s m a l l . The annual dry weight production of new f o l i a g e , stems, and i n some cases b e r r i e s , y i e l d e d by muskox food p l a n t s i s given i n Table T i l l . - 38 -Table V I I I Dry Weight Production of Sel e c t e d Muskox Food Species Thelon Game Sanctuary-Species Production i n Kgms. per acre. Summer Range I Winter Range I Winter Range I I C e t r a r i a c u l c u l l a t a ( B e l l . ) Ach. S a l i x R i c h a r d s o n i i Hook. S. a l a x e n s i s (Anderss.) Cov. S. arbusculoides Anderss. B e t u l a glandulosa Michx. Empetrum nigrum L. Ledum decumbens ( A i t ) Lodd. Andromeda P o l i f o l i a L. Vaccinium uliginosum L V. V i t i s - I d a e a L. var minus Lodd. 25.82 Kgs. 350.79 " 16.79 " 15.24 Kgs. 26.61 82.38 92.37 25.70 4.27 n ft ft n ft 41.56 » T o t a l Kgs./Acre 34.56 Kgs. 189.76 " 143.59 " 15.46 " 85.19 " 393.40 288.13 468.56 n - 39 -On summer range I S a l i x a l a x e n s i s was c a l c u l a t e d to produce 350,79 Kgs. per acre, the l a r g e s t y i e l d of any of the species weighed. T o t a l production per acre f o r t h a t range was 393,4 Kgs, per a c r e . On win t e r range 1 the l a r g e s t production was given by Labrador tea f o l l o w e d by crowberry, 92,37 Kgs, and 82.38 Kgs. per acre r e s p e c t i v e l y . B i r c h produced 26.61 Kgs. per acre, b i l b e r r y 4.27 Kgs. per acre and cowberry 41.56 Kgs. per a c r e . T o t a l p r o d u c t i o n was 238.13 Kgs. per ac r e . Winter range II gave a gr e a t e r t o t a l y i e l d of muskox food, i t being 463.56 Kgs. per ac r e . Crowberry c o n t r i b u t e d 139.76 Kgs, labrador* tea 143,59 Kgs., cowberry 35,19 Kgs, b i r c h 34,56 Kgs, and b i l b e r r y 15.46 Kgs. Lake Hazen Before examining the r e s u l t s of the chemical analyses of muskox food p l a n t s , i t w i l l be p e r t i n e n t to review the r e s u l t s of analyses of the ranges a t Lake Hazen, Ellesmere I s l a n d . The summer fe e d i n g s i t e s e l e c t e d f o r analyses was the lower p o r t i o n of a south-east f a c i n g slope of a mountain, t e n t a t i v e l y named Mount Ubyssey, which l i e s between the d e l t a s of the Snow Goose and Abbe1 r i v e r s , on the north shore of Lake Hazen. The area, a t the time of the study, was being browsed and grazed by muskoxen and had been used as summer range i n past years, from the i n d i c a t i o n s of much summer dung. The s o i l , the a n a l y s i s of which i s given i n Table V, was dry, f i n e c l a y , w i t h some c l a y hummock formations and l a r g e polygons. C h a r a c t e r i s t i c plants i n c l u d e w i l l o w ( S a l i x a r c t i c a L . ) , mountain avens (Dryas i n t e g r i f o l i a M. V a h l . ) , c i n q u e f o i l ( P o t e n t i l l a r u b i c a u l i s Lehm.), wheatgrass (Agropyron l a t i g l u m e - 40 -(Sc h r i b n . and Sm.), blue grass (Poa glauca M. Vahl.) and bladder-campion (Melandrium t r i f l o r u m (R. Br.) J . V a h l . ) . The r e s u l t s of the summer range studies are given i n Table IX. Table IX Lake Hazen Summer Range Transects I and I I P l a n t Species Occurrence Frequency and Area Coverage i n per cent • TransectI Transect I I Species Frequ. % Area Frequ. °/o Area Index Covered Index Covered S o i l 78.6 66.36 85.6 68.72 Moss .21 .4 .24 Deschampsia b r e v i f o l i a R. Br. 1. Poa glauca M. V a h l . .3 .4 1.2 1.04 Agropyron l a t i g l u r a e (Schribn.) .08 & Sm.) Rydb. .6 Kobresia myosuroides ( V i l l . ) etc. 1.5 1.44 .16 Carex stans D r e j . .3 .88 S a l i x a r c t i c a P a l l . 1.9 6.9 6.6 18.6 Polygonum viviparum L. .08 Cerastium a r c t i c u m Lge. Ar e n a r i a r u b e l l a (Wahlenb.) Sm. T T .08 Melandrium t r i f l o r u m (R. Br.) J . Vahl .16 T Papaver radicatum Rottb. T L e s q u e r e l l a a r c t i c a (Wormskj.) Wats T Draba groenlandicum E l . Ekman T T Erysimum P a l l a s i i (Pursh) Fern T S a x i f r a g a o p p o s i t i f o l i a L. .08 .16 S. t r i c u s p i d a t a Rottb. T P o t e n t i l l a r u b i c a u l i s Lehm T .8 .64 Dryas i n t e g r i f o l i a M. V a h l . 15.2 23.28 5.2 10.72 Aiidrosace s e p t e n t r i o n a l i s L. s. l a t . T P e d i c u l a r i s h i r s u t a L. T 41 -On the f i r s t transect of the summer range, mountain avens had a frequency of 15.2 per cent, willow 1.9 per cent and kobresia (Kobresia myosuroides V i l l . ) , 1.5 per cent. Two summer foods of low frequency were blue grass (Poa glauca M. vahl.) and carex (Carex stans Drej.). Soil frequency index was 78,6 per cent. On the second transect willow was the most frequently occurring plant with an index of 6.6 per cent, mountain avens following with 5.2 per cent, the blue grass with 1.2 per cent. Soil index was 85.6 per cent. Mountain avens covered the largest area of the plots examined on Transect 1, having a value of 23.28 per cent. Willow rated at 6.9 per cent, kobresia 1.44 per cent and sedge 0.88 per cent. Blue grass and moss each had an index of 0.4 per cent. Bare ground amounted to 66.36 per cent of the area. On the second transect, willow was the predominant plant, covering 18.6 per cent of the plots. Mountain avens followed with 10.72 per cent and blue grass with 1.04 per cent. Traces and other values were recorded for a number of additional species on both transects. The winter range I sites selected for study were f l a t troughs between the base of Mount Ubyssey and ridges running parallel to the mountain. The f i r s t site was at the 1,480 foot level or about 980 feet above the level of the lake. Much winter dung and some summer dung were present. Part of the site was inundated with a shallow seepage stream i n which vegetational growth was dense with species such as moss, willow, carex, cottongrass (Eriophorum  Scheuchzeri HoppeJ, knotweed (Polygonum viviparum L.), mouse-ear chickweed (Cerastium alpinum L.) and saxifrage (Saxifraga Hirculis - 42 -L. var propingua (E. Br.) Simm.J. The d r i e r p o r t i o n of the s i t e was humraocky, and contained such species as mountain avens, w i l l o w , A r c t a g r o s t i s l a t i f o l i a (R* Br.J G r i s e b . , mountain s o r r e l (Oxyria  digyna (L.J H i l l ) Juncus bi g l u m i s L . , Carex stans D r e j , Carex  a t r o f u s c a Schk., Luzula confusa L i n d e b l . and f o x t a i l (Alopecurus  a l p i n u s L .J i The second t r a n s e c t was at the 1,680 f o o t l e v e l and was a wet f l a t meadow through which seepage water flowed down a s l i g h t s l o p e . Much wi n t e r dung was evident, p a r t i c u l a r l y where the sedge, Carex  stans D r e j . , was most abundant. C h a r a c t e r i s t i c v e g e t a t i o n i n c l u d e d Carex stans D r e j . . w i l l o w , knotweed, mountain avens, f o x t a i l , juncus, moss, S a x i f r a g a H i r c u l i s L , v a r , propingua (R, Br.) Simm,, cottongrass ( E ^ a n g u s t i f o l i u m Honck, and Scheuchzeri Hoppe), a r c t a g r o s t i s , and equisetum (Equisetum arvense L.J The second w i n t e r range s e l e c t e d f o r examination was a r e l a -t i v e l y f l a t s i t e on the combined d e l t a fans of the Snow Goose and Abb§ r i v e r s , . The area was d i s s e c t e d w i t h braided streams from both r i v e r s . Large masses of willow-herb (Epilobium l a t i f o l i u m L . J , on which the muskoxen f e d i n summer, grew i n the g r a v e l stream beds. G e n e r a l l y , however, much of the s i t e contained almost pure stands of sedge (Carex stans D r e j . J i n the wet areas, w i t h patches of a r c t a g r o s t i s i n t e r s p e r s e d on the d r i e r s i t e s . Beds of cottongrass (E. Scheuchz:eri Hoppe J were mixed i n w i t h the sedge, along w i t h f o x t a i l and equisetum. On dry c l a y s , some Peschampsia b r e v i f o l i a R. Br,, mountain avens, w i l l o w and S a x i f r a g a o p p o s i t i f o l i a L. occurred. - 43 -Muskox wi n t e r dung was present throughout the area, w i t h most i n the sedge stands. The animals were observed f e e d i n g there i n the autumn and w i n t e r , by the m e t e o r o l o g i c a l p a r t y , which overwintered at Lake Hazen. There was very l i t t l e dung on the willow-avens s i t e . The r e s u l t s of the analyses of the v e g e t a t i o n occurrence and area coverage on w i n t e r ranges I and I I are given i n Tables X and X I . On t r a n s e c t s I and I I , of winter range I , moss formed the l a r g e s t ground cover and occurred most f r e q u e n t l y i n the p l o t s . - 44 Table X Lake Hazen Winter Range I , Transects I and I I 1 Species Transect I Transect I I Frequ. °/o Area Frequ. % Area Index Covered Index Covered L i c h e n T Moss 67.6 44.56 56.6 58.24 Equisetum arvense L. .48 1.0 1.28 Alopecurus a l p i n u s L. .48 .6 . 2 4 A r c t a g r o s t i s l a t i f o l i a (R. Br,) G r i s e b , 1.2 2.16 1.2 •96 Poa glauca M, V a h l , T Festuca b r a c h y p h y l l a Schultes T T Eriophorum a n g u s t i f o l i u m Honck Eriophorum Scheuchzeri Hoppe .08 2.4 .2 .08 .4 T Carex stans D r e j , 9.4 10.16 5.4 4.8 Carex a t r o f u s c a Schk, .56 1.84 Juncus b i g l u m i s L, .2 T .4 .16 Luzula confusa L i n d b l , .2 .08 .16 S a l i x a r c t i c a P a l l , 2.6 7.84 1.2 7.04 Oxyria digyna (L. ) H i l l T .6 T 1.68 Polygonum viviparurn L, 1.4 1.92 S t e l l a r i a l o n g i p e s Goldie s, lat, .2 T Cerastium alpinum L, T A r e n a r i a r u b e l l a (Wahlenb,) Sm, T A r e n a r i a R o s s i i R. Br, T Melandrium t r i f l o r u m (R. Br.) J . Vahl T T Papaver radicatum Rottb, T T Draba groenlandica E l . Ekman T T S a x i f r a g a f o l i o l o s a R. Br. T T S a x i f r a g a H i r c u l i s L. T .2 T S a x i f r a g a o p p o s i t i f o l i a L. .2 • t •- • - » ' T'. .'• Dryas i n t e g r i f o l i a M. Vahl 6.4 7.6 2.6 4.48 P e d i c u l a r i s h i r s u t a L. T T Clay 10.6 24.0 29.6 16.72 * 45 -Table XI Lake Hazen Winter Range I I P l a n t Species Occurrence Frequency and Area Coverage i n per cent, 4© p l o t s . Species Frequ. % Area Index Covered Moss 11.46 9.67 Equisetum arvense L. .833 .42 Alopecurus a l p i n u s L. A r c t a g r o s t i s l a t i f o l i a (R. Br,) Griseb Deschampsia b r e v i f o l i a R, Br, .416 T .416 .65 .416 Eriophorum Scheuchzeri Hoppe .625 .25 Carex stans D r e j . 5. 14.0 Juncus biglumis L. T S a l i x a r c t i c a P a l l , .416 1.42 S t e l l a r i a l o n g i p e s G o l d i e s, l a t , Braya purpurescens (R. Br,) Bungl, T T S a x i f r a g a o p p o s i t i f o l i a L. 2.083 .16 Dryas i n t e g r i f o l i a M, V a h l . 4.75 P e d i c u l a r i s h i r s u t a L. .283 T Clay 78.125 68.75 - 46 -On t r a n s e c t 1, the frequency index of moss was 67.6 per cent and i t s area coverage 44.56 per cent, and on t r a n s e c t I I , the f i g u r e s are 56.6 and 58.24. On both t r a n s e c t s c l a y occured second i n frequency and area coverage. As moss was c l o s e l y appressed to the ground and was not a v a i l a b l e as food t o muskoxen, the un-productive food area on the study p l o t s on t r a n s e c t I was 63.56 per cent and on t r a n s e c t I I , 74*96 per cent. Of the remaining p l a n t s , sedge was highest i n frequency (9.4$) and i n area covered (10.16$) on tr a n s e c t I , f o l l o w e d by mountain avens w i t h values of 6.4 per cent and 7.6 per cent. Willow frequency was 2.6 per cent and area covered t o t a l l e d 7.34 per cent. Knotweed and a r c t a g r o s t i s values were s i m i l a r , t h e i r frequency being 1.4 and 1.2, and area covered being 1 .92 and 2.16 per cents r e s p e c t i v e l y . On the second t r a n s e c t , sedge frequency was 5.4 per cent and equisetum 1.0 per cent. Willow covered the l a r g e s t area of the p l o t s , apart from moss and c l a y , w i t h a value of 7.04 per cent, f o l l o w e d by sedge (4.3%),, mountain avens (4.43%), cottongrass (E^ a n g u s t i f o l i u m Honck) (2.4%), Carex a t r o f u s c a Schk. (1.84%) knotweed (1.68%) and equisetum (1.23%). Several other p l a n t species were recorded w i t h values of l e s s than one per cent on both t r a n s e c t s and i n both c a t e g o r i e s of analyses. There were 14 species of p l a n t s recorded on win t e r range I I , h a l f of the number recorded on winter range I . Clay predominated i n frequency (73.125%) and area covered (63.75%) and i t , combined wit h moss whose values were 11.46 per cent and 9.67 per cent, r e -s p e c t i v e l y , gave an unproductive area p r o p o r t i o n of 73.42 per cent. - 47 -Sedge was the most abundant food plant, having a frequency of 5.0 per cent and an area coverage of 14.0 per cent. Mountain avens frequency value was 2.083 per cent and willow 0.416 per cent, while the per cent of the area of the plots they covered was 4.75 and 1.42 respectively. Plant production at Lake Hazen, Table XII, was determined for two species only, willow and the sedge, Carex stans Drej. On the summer range transect II, willow production was calculated to be 60.30 Kgs. per acre. On winter range I, willow production was calculated at 23.80 Kgs. per acre and sedge production at 21.85 Kgs. per acre. Table XII Dry Weight Production of Selected Muskox Food Species, Lake Hazen. Ellesmere Island Species Production in Kilograms per acre Summer Range Winter Range I Carex stans Drej. 21.85 Salix arcticaPall. 60.30 23.80 Total 60.30 45.65 48 -Comparisons o f the forage production f i g u r e s from muskox wi n t e r ranges obtained i n the present study, w i t h those obtained by Cowan (1946) and Webb (1957), on sheep and e l k w i n t e r ranges, i n Jasper and Banff N a t i o n a l Parks and by C l a r k e , et a l (1942) on pastures of domestic l i v e s t o c k , i n the southern p r a i r i e s of Canada, given i n Table X I I I , are most r e v e a l i n g . Table X I I I Comparison of Forage Pr o d u c t i o n of Ranges of the Northwest T e r r i t o r i e s w i t h those of Pastures of Domestic and Wild Ungulates of Southern Canada. I n v e s t i g a t o r Year L o c a l i t y V e g e t a t i o n a l P r o d u c t i o n i n Type Kilograms/Acre Summer Range Winter Range C l a r k e , et a l Cowan tfebb Tener Tener 1937-39 1946 1953 1957 1958 S. P r a i r i e s Jasper Nat. Park Banf Nat. Park Thelon Game Sanctuary Lake Hazen Short-grass P r a i r i e Mixed P r a i r i e Submontane Mixed P r . 120.20 Kgs.* 193.69 " 319.79 " 393.40 " 60.30 " 648.56 Kgs.* 508.20 n 430.76 " 396.88 " 159.24 n 552.73 " 544.50 « 288.13 * 468.56 " 45.65 " •Figures of C l a r k e , et a l , Cowan and Webb have been converted from pounds/acre. The w i n t e r range s i t e s of the Thelon Game Sanctuary compare f a v o u r a b l y i n amounts of annual forage produced w i t h the prod u c t i o n of Jasper and Banff Parks and southern p r a i r i e ranges. The Lake Hazen range, however, produced about one*-third to one-fourteenth of the forage o f the park and p r a i r i e ranges. Evaluations of the produ c t i o n of herbivorous animals i n high A r c t i c areas must be - 49 p r e d i c a t e d on the low amounts of forage a v a i l a b l e f o r a l l herbivorous species* Such low food production poses i n t r a - a n d i n t e r - s p e c i f i c problems f o r s u r v i v a l , p a r t i c u l a r l y f o r those forms which spend the wi n t e r months i n a r e l a t i v e l y r e s t r i c t e d area and which must contend w i t h snowi cover i n t h e i r search f o r food (see P r u i t t , 1959, f o r d i s c u s s i o n of caribou and snow r e l a t i o n s h i p s ) • Chemical Analyses of Muskox Food P l a n t s . Thelon Game Sanctuary As i n d i c a t e d i n the s e c t i o n on procedures, eight species of pl a n t s were c o l l e c t e d i n A p r i l , 1956 d u r i n g a wi n t e r study o f muskoxen, i n the north-east p o r t i o n of the Thelon Game Sanctuary. The r e s u l t s of the chemical analyses of those p l a n t s are gi v e n i n Table XIV. Table XIV Chemical Analyses of Muskox Food P l a n t s Thelon Game Sanctuary Winter. Range. 1956 Date C o l l e c t e d 1956 P l a n t Species Percentage Composition on Dry Matter Basis P r o t e i n (Nx6.25) "Fat" rude F i b r e Ash N. f r e e e x t r a c t A p r i l 10 A p r i l 22 A p r i l 14 A p r i l 10 tt A p r i l 4 tr n A p r i l 10 tt C e t r a r i a n i v a l i s and A l e c t o r i a ochroleuca Rhytidium rugosum ($edw.) Kindb. Agropyron sp. Agropyron sp. Betula glandulosa Michx. Empetrum nigrum L. tt tt Ledum decumbens ( A i t ) Lodd. Vaccinium u l i g i n o -sum L. V. V i t i s - I d a e a L. var , minus Lodd. 3.76 7.22 3.10 2*76 5.95 4.71 4.38 5.93 5.16 5.52 1.55 4.05 1.31 1.29 3.70 10.03 9.08 6.00 2.89 2.60 20.21 28.52 39.12 41.40 25.83 24.93 21.46 28.72 40.45 23.42 19.14 4.00 4.52 1.61 1.33 1.81 6.11 2.31 1.14 3.02 55.34 56.21 51.95 52.94 63.17 58.52 58.97 57.04 50.36 65.44 * 50 -A l l of the species analysed, except Agropyron sp., were being con-sumed by the muskoxen under o b s e r v a t i o n . The p r o t e i n value of each species v a r i e d between 2.76 per cent f o r an Agropyron sample and 7»22 per cent f o r the moss, Rfaytidium rugosum (Hedw.) K i n d l e . The important muskox foods, b i r c h , crowberry, l a b r a d o r t e a , b i l -b e r r y and cowberry gave p r o t e i n values which were between 4.5 and 6 per cent. Highest f a t values were obtained from crowberry (9»08 to 10.03%) and l a b r a d o r tea (6.00%J w i t h moss (4.05%) and b i r c h (3.70%) being somewhat l e s s . Lowest f a t values were obtained from l i c h e n s (1.55%) and wheatgrass (1.29%). Crude f i b r e values were highest i n the wheatgrass (39*12% and 41.40%) and b i l b e r r y (40.45%) samples, w i t h the other species having values between 20 and 29 per cent. Ash content was un-u s u a l l y high i n the l i c h e n s (19.14%) but t h i s may have been caused p a r t l y by s o i l which was d i f f i c u l t t o remove from the p l a n t s . Values of other species ranged between one and s i x per cent. M i n e r a l composition of the forage was not determined as samples were too s m a l l . The n i t r o g e n f r e e e x t r a c t values v a r i e d between 51.95 per cent and 65.44 per cent. I n 1957 a l a r g e r s e r i e s of p l a n t s from muskox ranges i n the Sanctuary were c o l l e c t e d and subsequently analysed, the r e s u l t s of which are d e t a i l e d i n Table XV, according t o the ranges on which the p l a n t s were c o l l e c t e d . - 51 * Table XV Chemical Analyses o f Muskox Food P l a n t s , Thelon Game Sanctuary, Summer and Winter Ranges. 1957.  Range anc Percentage Composition on Dry Matter Basis Date P l a n t Species Protein Fat. Crude Ash N. Free Ca P Colle c t e c [Nx6.25) F i b r e Extract Summer I J u l y 23 S a l i x R i c h a r d s o n i i .46 Hook 23.93 2.07 15.97 9.95 48.08 1.03 n ft tt tt 21.63 2.55 13.63 8.01 54.18 1.11 .40 tt ft S. a l a x e n s i s (Anderss.) Co v. 24.72 2.67 23.83 7.87 40.91 .69 .50 tt ft tt it tt 22.85 3.40 17.93 7.72 48.-10 .68 .47 n ft S. arbuscoloides Anderss. 26.47 2.26 14.76 7.00 49.51 .62 .54 n tt tt tt n 22^96 2.63 12.62 6.13 55.66 .62 .48 Summer I I J u l y 30 S a l i x R i c h a r d s o n i i Hook 16.82 2.77 12.76 6.31 61.34 1.29 • 22 tt ft S. a l a x e n s i s (Anderss.) Cov. 21.75 3.38 16.98 6.69 51.20 .84 .29 tt " S. arbusculoides Anderss. 18.98 2.58 12.56 4.84 61.04 .79 .27 ft ft rt " ft n 17.40 3.37 13.69 5.04 60.50 .87 .21 o ft Betula glandulosa 18.84 58.00 Michx. 6.21 13.24 3.71 .29 Winter I Aug. 8 C e t r a r i a c u l c u l l a -t a ( B e l l . ) Ach. 3.71 2.38 11.23 2.56 80.02 .32 .07 ft n Polytrichum j u n i -per inum & Aulacom-28.64 5.16 .36 nium turgidum 4.99 3.90 57.31 .10 n n Betula glandulosa Michx. 9.28 6.00 20.06 1.87 62.79 .27 .14 n rt Empetrum nigrum L. 5.15 10.43 23.10 2.40 58.92 .46 .07 n n Ledum decumbens L. 7.26 6.43 25.88 1.89 58.54 .46 .09 tt « Andromeda P o l i f o H a L . 6.29 4.04 23.92 3.85 61.90 .56 .08 tt tt Arctostaphylos a l -pin a (L.) Spreng. 1 8.55 2.54 9.45 5.37 74.09 .57 .13 n tt Vaccinium uliginosumL^.74 3.10 31.06 1.88 57.22 .36 .09 tt tt V. V i t i s - I d a e a L. var . minus Lodd 5.43 3.34 19.94 2.25 69.04 .53 .09 Winter I I Aug. 9 Polytrichum j u n i - 4.64 2.89 27.89 8.61 55.97 .36 .09 per inum TI n BMicnx S - L a n d u ^ o s a 8.69 5.53 25.38 1.80 58.60 • 3 £ •x7 ft tt Empetrum nigrum L. f1! 10.38 m% 3.01 .48 .06 ft Ledum decumbens L. 6.38 7.14 2.30 56.88 .40 .09 ft tt Vaccinium uliginosum L , 6.76 3.19 31.73 4.26 54.06 .33 .11 ft tt V. V i t i s - I d a e a L. 6.09 67.44 t?6 v a r . minus Lodd. 2,93 20,47 3.07 .10 - 52 -The d u p l i c a t i o n of species of p l a n t s c o l l e c t e d on summer ranges I and I I does not r e f l e c t a d i f f e r e n c e i n c o l l e c t i n g s t a t i o n s but only the f a c t t h a t the m a t e r i a l s from one s i t e were put i n t o two c o n t a i n e r s . Each sample was t r e a t e d s e p a r a t e l y to see what v a r i a t i o n , i f any, might e x i s t . The p r o t e i n values on summer range I of the three w i l l o w species examined were between 21.63 and 26.47 per cent. The favoured muskox food, S a l i x a l a x e n s i s (Anderss.) Cov., y i e l d e d values of 22.85 and 24.72 per cent i n the two samples from the same area. On the second summer range the p r o t e i n values f o r the same w i l l o w species were lower, p a r t i c u l a r l y f o r Richard-s o n i i Hook and S^ arbusculoides Anderss. The b i r c h value of 18.84 per cent was equal to t h a t of the two p r e v i o u s l y mentioned w i l l o w s p e c i e s . P r o t e i n values of p l a n t s on both winter ranges were much l e s s than those of summer range p l a n t s . The highest v a l u e , 9.28 per cent, was giv e n by b i r c h and the lowest, 3.71 per cent, by the l i c h e n C e t r a r i a c u l c u l l a t a ( B e l l . ) Ach. The b i r c h values are p a r t i c u l a r l y i n t e r e s t i n g i n t h a t they are about h a l f of those on summer range I I . The content of f a t i n w i l l o w s c o l l e c t e d on the summer ranges v a r i e d between 2.07 and 3.40 per cent. B i r c h on summer range I I had a value of 6.21 per cent, s i m i l a r to that species value on both w i n t e r ranges, Crowberry f a t content was the highest of p l a n t s c o l l e c t e d on both w i n t e r ranges, the values f o r w i n t e r range I being 10.43 per cent and wi n t e r range I I , 10.38 per cent. The l i c h e n , C e t r a r i a c u l c u l l a t a ( B e l l . ) Ach. contained the l e a s t - 53 -f a t , i t s value being 2 . 3 8 per cent. On both summer ranges, the crude f i b r e content of S a l i x  a l a x e n s i s was the highest of the w i l l o w s , i t s per cent composi-t i o n being 17*93 f o r p l a n t s from the f i r s t range and I6v98 f o r p l a n t s from the second. The f i b r e content of most of the ana-l y z e d p l a n t s from the two wi n t e r ranges was s u b s t a n t i a l l y higher than summer range s p e c i e s v a l u e s . Values ranged between 20.06 per cent f o r b i r c h and 31.73 per cent f o r b i l b e r r y . Two p l a n t s of low crude f i b r e content were the l i c h e n (11.23%) and bearberry (Arctostaphylos a l p i n a (L.) Spreng.) (9.45%). Ash content of the w i l l o w s from both summer ranges v a r i e d between 4.84 and 9.95 per cent, the higher values belonging t o pl a n t s from summer range I . With the exception of moss sp e c i e s , bearberry and p o s s i b l y b i l b e r r y , ash values of p l a n t s c o l l e c t e d on both w i n t e r ranges were r e l a t i v e l y low, being between 1.80 per cent and 3»85. N i t r o g e n - f r e e e x t r a c t values of w i l l o w s on summer range I were between 40.91 per cent and 55.66 per cent, and on the second range were between 51.20 per cent and 61.34 per cent. The value of b i r c h from the l a t t e r area was 58.00 per cent. Of the wi n t e r range s p e c i e s , l i c h e n (80.02%) and bearberry (74.09%) f i g u r e s were the h i g h e s t . Values f o r the other p l a n t s examined were between 54.06 per cent ( b i l b e r r y ) and 6 9 . 0 per cent (cowberry). The w i l l o w , S a l i x R i c h a r d s o n i i Hook, y i e l d e d the highest per-centage composition of calcium of a l l p l a n t s examined on the f o u r Thelon ranges. Two samples from the f i r s t summer range gave values of 1.03 and 1 . 1 1 per cent and one sample from the second range was 1 . 2 9 per cent i n va l u e . Other w i l l o w species y i e l d e d percentages between 0.62 and 0.87. Calcium compositions of wi n t e r range p l a n t s were con s i d e r a b l y lower, the values of the d i f f e r e n t species f a l l i n g between the low of 0.27 per cent i n the case of the b i r c h and the high of 0.57 y i e l d e d by bearberry. Highest phosporous values were found i n w i l l o w s growing on summer range I . S a l i x R i c h a r d s o n i i Hook averaged 0.43 per cent, S. a l a x e n s i s (Anderss.) Cov., 0.485, per cent and S.  arbusculoides Anderss., 0.51 per cent. The same species on summer range I I y i e l d e d values of about h a l f of the previous f i g u r e s . B i r c h from the same range gave a f i g u r e of 0 .29 per cent. The phosphorous contents of wi n t e r range p l a n t s examined were much lower than those of any of the summer ranges s p e c i e s . Crowberry samples from each winter range, f o r example, contained 0.06 and 0.07 per cent phosphorous. The highest phosphorous content i n wi n t e r range p l a n t s was found i n the b i r c h , which y i e l d e d 0.17 per cent, but most species were under 0.11 per cent. Lake Hazen S i x species of p l a n t s were c o l l e c t e d i n 1958, from the muskox summer range, near the north shore of Lake Hazen, and two species from winter range I I (Table X V I ) . _ 55 — Table XVI Chemical Analyses of Muskox Food P l a n t s Lake Hazen, Ellesmere I s l a n d , Summer and Winter Ranges. 1958.  Range and Date C o l l e c t e d P l a n t Species Percer taee Com© oe itlon on Drv Matter Basis Proteif (Nx 6.25, Fat Crude F i b r e Aah N.Free Ex-t r a c t I?a Summer J u l y 26 Poa glauca B^Vanl. 8.61 1.94 26.40 5.03 58.02 0.15 0,22 IT n tt ft tt ft 8.80 1.84 26.87 4.51 57.98 0.15 0.20 tt n tt tt tt tt 10.87 1.79 21.24 6.07 60.03 0.17 0.29 tt tt Agropyron HatLglume ft n TSchribn&Sm) Rydb. 7.82 1.44 28.35 4.80 57.59 0.30 0.18 tt tt 7.50 1.45 29.24 4.67 57.14 0.26 0.17 tt tt S a l i x a r c t i c a P a l l , 11.90 2.30 13.02 7.45 65.33 1.70 0.31 tt tt « tt tt 12.59 2.16 12.90 7.31 65.04 1.69 0.32 ft tt tt tt tt 12.60 2.42 12.95 7.40 64.63 1.67 0.32 ft tt tt tt tr 12.55 2*21 13.28 7*54 64.4? 1.72 0.31 lt tt Melandrium t r i f l o -rum (R. Br.) J. Vahl. 9.14 7.63 21.65 9.41 52.17 0.40 0.23 t» tt Dryas i n t e g r i f o l i a M. Vahl. 5.38 2.41 14.40 12.54 65.27 2.92 0.09 ft n ft n tt 5.37 2.53 14.86 14.71 62.53 2.96 0.09 tt tt Epilobium l a t i f o -2.08 l i u m L. 12.43 11.90 9.17 64.42 2.13 0.32 ft tt tt tt tt 33.24 2.48 7.96 9.22 67.10 2.56 0.32 Winter I J u l y 29 Carex stans D r e j . 14.65 2.91 19.94 5.45 57.05 0.45 0.28 tt tt ft tt tr 14.99 2.65 17.21 6.91 58*24 0.56 0.27 tt tt n tt tt 13.84 2.81 17.85 5.43 60.07 0.43 0.31 tr tt tt tt tt 14.55 2.79 18.64 5.40 58.62 0.43 0.28 n n S a l i x a r c t i c a P a l l , 13.93 3.28 15.57 5.79 63.43 1.45 0.17 n n tt tt tt 12.80 3.19 14.83 6.25 62.93 1.53 0.17 tt ft tt tr n 13.37 3.34 13.82 7.36 62.11 1.65 0.18 - 56 -As the case o f the samples from the Thelon Game Sanctuary, the s e v e r a l samples l i s t e d under one species r e l a t e to the number o f containers w i t h the p l a n t m a t e r i a l . P r o t e i n percentages of blue grass (Poa glauca M, Vahl.) v a r i e d between 8 , 6 1 and 1 0 . 8 7 ; f o r wheat grass (Agropyron l a t i - glume etc,) between 7 . 5 0 and 7 , 8 2 and f o r w i l l o w ( S a l i x a r c t i c a P a l l . ) between 1 1 . 9 0 and 1 2 . 6 0 . Fireweed (Epilobium l a t i f o l i u m L.) values were s i m i l a r t o w i l l o w , the two samples y i e l d i n g 1 2 . 4 3 and 1 3 . 2 4 per cent. Bladder campion (Melandrium t r i f l o r i u m (R. Br.) J . Vahl) and mountain avens (Dryas i n t e g r i f o l i a M, Vahl) values were lower, being 9 . 1 4 and 5 . 3 7 per cent r e s p e c t i v e l y . The p r o t e i n compositions of the two winter range species analyzed were r e l a t i v e l y h i g h , t h a t f o r sedge (Carex stans Qrej) v a r y i n g from 1 3 . 8 4 to 1 4 . 9 9 per cent and f o r w i l l o w between 1 1 . 9 3 and 1 3 . 3 7 per -cent. Except f o r bladder campion which contained 7 . 6 3 per cent f a t , values were l e s s than 3 . 5 per cent f o r a l l species analyzed from Lake Hazen ranges. The two grass species were p a r t i c u l a r l y low i n f a t j having compositions of l e s s than two per cent. Percentages o f f a t i n w i l l o w , mountain avens and fireweed from the summer range v a r i e d between two and two and one-half per cent. Sedge from the wi n t e r range I had f a t values between 2 . 6 5 and 2 . 9 1 per cent while w i l l o w f a t values had the narrow range of from 3 . 1 9 to 3 . 3 4 per cent. The crude f i b r e composition of blue g r a s s , wheatgrass and bladder campion exceeded 2 1 per cent. Willow values were much l e s s , being of the order of 1 3 per cent. Mountain avens and f i r e -- 57 -weed a l s o contained l e s s crude f i b r e . Crude f i b r e composition of the w i n t e r range sedge v a r i e d between 17.21 and 19.94 per cent, w h i l e t h a t of the w i l l o w v a r i e d between 13.82 and 15.57 per cent. Ash content was highest i n the mountain avens, t h a t species y i e l d i n g between 12.54 and 14.71 per cent. Willow-herb ash content was between 9.17 and 9.22 per cent, and a s i m i l a r value of 9.41 per cent was recorded f o r the bladder campion. The ash content of the other species c o l l e c t e d v a r i e d between 4.51 per cent f o r a blue grass sample to 7.54 per cent f o r a w i l l o w . Nitrogen f r e e e x t r a c t percentages i n the Lake Hazen p l a n t s c o l l e c t e d were r a t h e r uniform, most f a l l i n g between 57 and 65 per cent. Bladder campion alone had a r e l a t i v e l y low value of 52.17 per cent. Mountain avens of the summer range p l a n t s examined, had the highest calcium content, averaging 2.94 per cent, f o l l o w e d by f i r e -weed with a 2.34 per cent average and w i l l o w at 1.69 per cent. The grasses gave r e l a t i v e l y low values, p a r t i c u l a r l y Poa glauca M. Vahl. Willow on the wi n t e r ranges s t u d i e d , w i t h an average content of 1.16 per cent, gave over twice the calcium value of sedge. The phosphorous contents of w i l l o w (0.315 per cent) and f i r e -weed (0.32 per cent),on summer range, were s i m i l a r i n value. Mountain avens gave a low value of 0.09 per cent but the grasses contained higher amounts. Of the wi n t e r range p l a n t s examined, Carex stans D r e j . phosphorous content was higher, averaging 0.285 per cent w h i l e w i l l o w average 0.17 per cent. - 5 8 -Comparisons of chemical analyses of muskox range p l a n t s w i t h analyses undertaken of p l a n t s from ranges of other w i l d North American bovids i s not p o s s i b l e a t present. At l e a s t , I have been unable t o f i n d any published references t o such work done on foods of mountain sheep, b i s o n or goats. There are numerous r e p o r t s of analyses of deer and other c e r v i d forage but as muskox ranges most c l o s e l y resemble the open, grass-covered ranges of ranchlands u t i l i z e d by domestic bovids, c e r v i d forage analyses w i l l not be used f o r comparison. Considerable work has been done on the chemi-c a l composition of n a t i v e forage p l a n t s of south-western Canada u t i l i z e d by domestic l i v e s t o c k . One such work i s t h a t of Clarke and T i s d a l e (1945) which w i l l form a b a s i s f o r comparison w i t h the present study. The above authors analyzed p l a n t s from f i v e main range types, Shortgrass P r a i r i e , Mixed P r a i r i e , S a n d h i l l Vegeta-t i o n , Submontane P r a i r i e and F o r e s t . Chemical values were d e t e r -mined of a number of species from each type to i l l u s t r a t e d i f f e r -ences i n values, i n d i f f e r e n t p a r t s of a p l a n t and d i f f e r e n c e s i n seasonal values as w e l l . Because species composition and d e n s i t y d i f f e r so g r e a t l y , d i r e c t comparison w i t h muskox forage species i s not p o s s i b l e . Examination of Clarke and T i s d a l e r e s u l t s , however, u s i n g h i s "medium seed" category of time of c o l l e c t i o n , would sug-gest t h a t f i v e species of grasses of the shortgrass p r a i r i e type o f f e r l e s s p r o t e i n , n i t r o g e n - f r e e e x t r a c t , calcium and phosphorous than the w i l l o w s of Thelon summer ranges. They o f f e r more f a t and calcium than two species of grasses from Lake Hazen ranges, but l e s s phosphorous,nitrogen-free e x t r a c t and p r o t e i n . Lake Hazen w i l l o w , which i s the most important summer food-.species of musk-oxen, has higher p r o t e i n , n i t r o g e n - f r e e e x t r a c t , calcium and - 59 -phosphorous content. Winter range foods of Thelon muskoxen have approximately the same p r o t e i n and phosphorous values as shortgrass p r a i r i e grasses but higher f a t , n i t r o g e n - f r e e e x t r a c t and calcium v a l u e s . The two Lake Hazen w i n t e r foods examined contained higher amounts of p r o t e i n , f a t , n i t r o g e n - f r e e e x t r a c t and calcium. Phophorous values were a l s o g r e a t e r . Comparisons of chemical values of Thelon summer range p l a n t s w i t h values obtained from f o r b s and shrubs from the Short-grass P r a i r i e and from p l a n t s from Mixed P r a i r i e , S a n d h i l l Vegetation, Submontane P r a i r i e and Forest range types showed tha t the Thelon p l a n t s were higher i n a l l c a t e g o r i e s . The forage from Thelon w i n t e r ranges, however, were lower i n values of p r o t e i n and phosphorous and higher i n f a t and n i t r o g e n - f r e e ex-t r a c t . The Lake Hazen summer and w i n t e r range forage g e n e r a l l y had somewhat lower p r o t e i n content than forage from range types other than the Shortgrass P r a i r i e , but g e n e r a l l y higher values of f a t and n i t r o g e n - f r e e e x t r a c t . Calcium and phosphorous values were s i m i l a r . I n summary, the comparison between c a t t l e ranges of south-ern A l b e r t a and Saskatchewan and muskox ranges of the Thelon Game Sanctuary suggests t h a t apart from low phosphorous values and somewhat lower p r o t e i n content of w i n t e r foods, the Thelon f o r a -ge sample values were e q u a l l y as good or s u p e r i o r . The Lake Hazen range samples exceeded chemical values of the shortgrass p r a i r i e forage and had higher values of f a t and n i t r o g e n - f r e e e x t r a c t but lower values of p r o t e i n than p l a n t s from the other range types examined by C l a r k e and T i s d a l e . - 60 -Feeding Habits D i e t The muskox has a r a t h e r d i v e r s e d i e t which v a r i e s w i t h the season and w i t h the geographical l o c a t i o n of the animals. In March and A p r i l , 1956, a number of muskoxen were observed over a p e r i o d of f i v e weeks on t h e i r winter range, i n the Thelon Game Sanctuary. Two herds, t o t a l l i n g 68 animals were checked p e r i o d i -c a l l y f o r food h a b i t s and f e e d i n g behaviour, among other objec-t i v e s . Narrow-leaf Labrador tea (Ledum decumbens L.) appeared to be a p r e f e r r e d food species f o r these animals along w i t h crowberry (Empetrum nigrum L . ) , cowberry (Vaccinium V i t i s - I d a e a L. var. minus Lodd.), b i l b e r r y (V. uliginosum L.) and ground b i r c h ( B e t u l a  glandulosa Michx.). Lichens ( C e t r a r i a n i v a l i s and A l e c t o r i a  ochroleuca) and moss (Rhytidium rugosum (Hedw. Kindb.) appeared to be eaten i n c i d e n t a l l y . The above foods were obtained on windward tundra slopes and h i l l tops, where snow depth was two to three inches. A hard granular l a y e r encrusted the v e g e t a t i o n , the depth hoar of P r u i t t ' s (1959) terminology. The feeding areas were scraped c l e a r of snow by the f r o n t hoofs of the animals and v e g e t a t i o n was g e n e r a l l y eaten to the ground. B e l l heather (Cassiope tetragona (L.) was not eaten ( p o s s i b l y because of an a v e r s i o n to the aromatic o i l s i n the s p e c i e s ) . An instance was recorded of one of the above herds feeding i n the f o r e s t e d p o r t i o n of a small r i v e r v a l l e y . The feeding was con-f i n e d c h i e f l y to willow ( S a l i x sp.) and cowberry growing along the r i v e r bank. Wheatgrass (Agropyron sp.) and l i c h e n s were untouched, although a v a i l a b l e , and b i r c h was only o c c a s i o n a l l y browsed. - 61 -Summer food preferences of muskoxen i n the Thelon Game Sanctuary were recorded i n 1952, 1956 and 1957, p a r t i c u l a r l y i n the l a t t e r y e ar. I n J u l y and the f i r s t h a l f of August the animals s e l e c t e d w i l l o w s , notably S a l i x a l a x e n s i s . S a l i x R i c h a r d s o n i i and S, arbus- c u l o i d e s were consumed to a much l e s s e r degree, and b i r c h was only o c c a s i o n a l l y eaten. Sedges (Carex stans. C, c a p i t a t a ) rush (Juncus  castaneus), blue grass (Poa a l p i n a ) and h o r s e t a i l (Equisetum arvense) were consumed when the muskoxen moved along the banks of small t r i b u t a r y streams where w i l l o w s were l e s s abundant and where the above p l a n t species were more frequent. A number of observations of muskox food preferences were made at Lake Hazen, northern Ellesmere I s l a n d , from June 2 to August 17, 1958, The stomach contents of an a d u l t b u l l c o l l e c t e d June 2, c o n s i s t e d l a r g e l y of d r i e d grasses (Poa sp..Alopecurus a l p i n u s and Festuca s p , ) , w i l l o w ( S a l i x a r c t i c a ) t w i g s , Carex stans and some dryas (Dryas i n t e g r i f o l i a ) , Snow covered the landscape and tem-peratures were w e l l below f r e e z i n g . The rumens of two o l d b u l l s , which died during the w i n t e r of 1957-58, were examined during the f o l l o w i n g summer. One rumen contained w i l l o w and some f o x t a i l (Alopecurus a l p i n u s L , ) , the other, w i l l o w , f o x t a i l , moss and dryas. Other evidence such as presence of w i n t e r dung, suggested t h a t p r i n c i p a l f e e d i n g areas i n w i n t e r were wet slopes where sedge (Carex s t a n s ) , w i l l o w , f o x -t a i l and cottongrasses (Eriophorum sp,) grew. With the m e l t i n g of the snow cover and appearance of new green v e g e t a t i o n , from l a t e June to e a r l y J u l y , the muskoxen grazed and browsed more wi d e l y , feeding on Mountain S o r r e l (Oxyria - 62 -digyna) Carex nardina. Carex s t a n s , blue grass (Poa glauca) and new w i l l o w growth, e a t i n g both leaves and twigs of the l a t t e r plant. An a d u l t b u l l c o l l e c t e d J u l y 18 was found to have f e d almost ex-c l u s i v e l y on w i l l o w . Large areas w i t h w i l l o w growth were found on d r i e r c l a y slopes and i t i s s i g n i f i c a n t t h a t muskox summer dung i s confined more to t h a t p l a n t formation than to the wet sedge slopes. As the summer progressed other p l a n t species were u t i l i z e d . j P ^ e c i f i c e f f o r t s were made by the muskoxen under study to o b t a i n '*•*'•• • c e r t a i n foods/. The broad-leaved willow-herb (Epilobium l a t i f o -l i u m L.)growing on the dry rocky bottom of a stream bed was eaten by a herd of 15 on J u l y 19, and i n the other areas, by other animals during the summer. Bladder-campion (Melandrium t r i f l o r u m (R. Br.) J . Vake and blue grass were found to occur i n patches, r a t h e r than being u n i f o r m l y d i s t r i b u t e d over the range. Muskoxen, when they encountered those p l a n t s , grazed them i n t e n s i v e l y and s e l e c t i v e l y . They took the centre s t a l k s of the P o a f l e a v i n g the h o r i z o n t a l l y growing p e r i p h e r a l s t a l k s . The Poa p l a n t s grew s p a r s e l y on c l a y slopes, although grouped i n an area, and were i n a s s o c i a t i o n w i t h such p l a n t s as wheatgrass (Agropyron l a t i g l u m e ) ( S c h r i b n . & Sm.) Rhybd., and fescue (Festuca b r a c h y p h y l l a Schultes) which were not eaten. Other a s s o c i a t e d p l a n t s i n c l u d e d c i n q u e f o i l ( P o t e n t i l l a p u l c h e l l a Pursh) and fleahane ( E r i g e r o n compositus Pursh) which were eaten c a s u a l l y . During the f i r s t two weeks i n August, the animals continued to feed on blue grass and w i l l o w on d r i e r s l o p e s , but a l s o f e d on Carex stans« cott o n grass (Eriophorum Scheuchzeri Hoppe) h o r s e t a i l , knotweed (Polygonum viviparum L.) and f o x t a i l , i n wetter drainage - 63 -slopes and shallow stream beds. By the middle of August, however, w i l l o w s were t u r n i n g y e l l o w and i t was n o t i c e d t h a t muskoxen were fe e d i n g l e s s on them and more on the s t i l l succulent h y d r o p h i l s . The above l i s t o f p l a n t s known to be eaten by muskoxen, i n the Thelon Game Sanctuary and at Lake Hazen, cannot be considered as complete. Other grasses, sedges, herbaceous forms and other p l a n t species probably are consumed to some degree. Two species not observed eaten were wheatgrass and b e l l heather. A comparison of species eaten i n the Thelon r e g i o n w i t h those i n the Lake Hazen area r e v e a l s t h a t a gr e a t e r p r o p o r t i o n of winter foods of the Thelon animals are_ woody. Such p l a n t s as labr a d o r t e a , crowberry, cowberry, b i l b e r r y and b i r c h are not a v a i l a b l e to high A r c t i c muskoxen, who must depend on w i l l o w , dryas, and d r i e d grasses and sedges f o r w i n t e r sustenance. The s i g n i f i c a n c e of t h i s f a c t i s discussed l a t e r . Feeding Behaviour The muskox gets i t s food by wrapping the tongue around such p l a n t s as grasses and sedges and t e a r i n g o f f leaves and stems, or by b i t i n g o f f the leaves and t e r m i n a l twigs of short p l a n t s such as the p r o s t r a t e A r c t i c w i l l o w . On the A r c t i c mainland, where w i l l o w s may ex c e e d j ? s i x f e e t i n h e i g h t , muskoxen may s t r i p the leaves and t e r m i n a l twigs by wrapping t h e i r tongues around the f o l i a g e and j e r k i n g the head up or down. I n the Thelon area, i t i s not unsual to f i r s t detect the presence of a muskox by the v i o l e n t t h r a s h i n g of a w i l l o w bush. As a r u l e , muskoxen do not feed i n t e n s i v e l y i n one spot i n summer, even should the v e g e t a t i o n be s u r p l u s . When i n w i l l o w - 64 -t h i c k e t s , the animals move through s l o w l y and may spend s e v e r a l hours a l t e r n a t e l y browsing and ruminating. I t i s unusual f o r a herd to remain at one s i t e , f e e d i n g on one r e s t r i c t e d area, f o r more than a day. The animals move up and down r i v e r systems, along l a k e shores, or across tundra, browsing and r e s t i n g but never remaining i n one spot u n t i l a l l food i s f u l l y used. S o l i -t a r y b u l l s can be e q u a l l y i f not more r e s t l e s s , wandering much f u r t h e r w h i l e feeding, and searching f o r mates. Other s o l i t a r y b u l l s , however, have been observed to stay w i t h i n an area of two to three square m i l e s f o r as lo n g as two weeks. Undoubtedly the r a t e at which the v a r i o u s herds and lone i n d i v i d u a l s move about the country v a r i e s c o n s i d e r a b l y . Some in f o r m a t i o n on the r a t e of t r a v e l i n summer was obtained i n 1952 when three herds were f o l l o w e d f o r a time down the Thelon R i v e r . The c o n t i n u i t y of i d e n t i f i c a t i o n of the three herds was s i m p l i -f i e d by the r e c o g n i t i o n of i n d i v i d u a l characters of the animals i n each herd. The f i r s t herd was recorded J u l y 23rd, on the west bank of the Thelon R i v e r , e i g h t miles downriver; on J u l y 26th, i t passed by our camp a t Hornby Ts Bend and August 1 s t , i t was about f o u r m i l e s f u r t h e r downriver. Between J u l y 23rd and August 1 s t , then, t h i s herd had t r a v e l l e d twenty m i l e s , or an average r a t e of two and one-half m i l e s per day. The second and t h i r d herds upon which more l i m i t e d informa-t i o n about r a t e of t r a v e l was obtained, were about twelve m i l e s above the F i n n i e R i v e r August 9 t h . , on the north bank of the Thelon. The herds were f e e d i n g about one m i l e apart, when f i r s t s i g h t e d and remained there u n t i l the l a t e afternoon of the 10th, when a downriver movement s t a r t e d . On the 11th, both herds were found between three and f o u r m i l e s nearer t o the F i n n i e R i v e r . Winter observations of muskoxen suggest t h a t a herd may remain f o r s e v e r a l days feeding i n one p l a c e , p o s s i b l y because a p a r t i c -u l a r l y good food source was a v a i l a b l e . Other herds and i n d i v i d u a l s , however, d i d move more f r e q u e n t l y but the r a t e of movement d i d not appear to be as r a p i d as i n summer. Perhaps conservation of en-ergy i s achieved i n t h i s way i n the season when energy requirements would be h i g h . The wide degree of l i g h t i n t e n s i t i e s , ranging from long periods of darkness i n w i n t e r to periods of i n t e n s e g l a r e from snow i n s p r i n g months, poses problems to muskoxen of e f f i c i e n t v i s i o n f o r f o r a g i n g under those v a r i e d c o n d i t i o n s . According to Walls (1942), the ungulate eye, which i s l a r g e , c o n s i s t s of a duplex r e t i n a of rods and cones and contains an area c e n t r a l i s . The l a t t e r i s a small pure cone area f o r r e t a i n i n g v i s u a l a c u i t y which might be l o s t as a r e s u l t of the duplex r e t i n a arrangement. The p u p i l i s h o r i z o n t a l l y r e c t a n g u l a r and corpora n i g r a are present along the p u p i l margins. The s l i t p u p i l arrangement permits com-p l e t e c l o s u r e of the p u p i l under i n t e n s e l i g h t c o n d i t i o n s , an im-p o s s i b i l y w i t h c i r c u l a r p u p i l s . The corpora n i g r a are a device f o r s h i e l d i n g the p u p i l from the intense g l a r e coming d i r e c t l y downward or r e f l e c t e d upward from the ground (snow). There are three ways i n which the ungulate eye i s s t r u c t u r a l l y s u i t e d to n o c t u r n a l v i s i o n . One i s the presence of a tapetum fibrosum of the choroid which permits g r e a t e r d i s c r i m i n a t i o n of objects a t n i g h t , as incoming l i g h t i s r e f l e c t e d back through the v i s u a l c e l l s . - 66 -Because the eye i s l a r g e , a l a r g e number of rods are present, the second c h a r a c t e r i s t i c , which, combined w i t h a l a r g e degree of summation, gi v e s the ungulate good night v i s i o n . Muskoxen are not unique i n f o r a g i n g i n darkness. Domestic l i v e s t o c k such as c a t t l e and w i l d ungulates such as deer, forage i n darkness w i t h l i t t l e evident d i f f i c u l t y i n s e l e c t i n g d e s i r e d foods. Muskox eyes may not be any d i f f e r e n t s t r u c t u r a l l y from those of other b o v i d s , p a r t i c u l a r l y , but by u s i n g a combination of memory, sense of smell and t h e i r v i s i o n , they are able to o b t a i n necessary food during p e r i o d s of darkness, and t o other-wise cope w i t h t h e i r environment. I n t e r s p e c i f i c Competition f o r food Muskoxen share the A r c t i c w i t h other r e s i d e n t herbivorous mammals, car i b o u (Rangifer s p . ) , hares (Lepus s p . ) , ground s q u i r r e l s and microtine genera such as Dicrostonyx. Lemmus and Mic r o t u s . Caribou may occupy the same areas as muskoxen during s p r i n g , summer or autumn months, and according t o the studie s of B a n f i e l d (1954) and K e l s a l l (1959), consume many p l a n t s during those months which are not muskox food species. Some, however, such as w i l l o w s p e c i e s , dwarf b i r c h , blue grass and cowberry are species which muskoxen consume e i t h e r i n summer or w i n t e r . A r c t i c hares are known t o feed on such p l a n t s as w i l l o w s and dryas. Lemmings consume a number of d i f f e r e n t p l a n t s , i n c l u d i n g sedges and grasses. Wien numbers of cari b o u , hare or m i c r o t i n e are low, food competition w i t h muskoxen would be n e g l i g i b l e . Caribou on the A r c t i c mainland, however, may migrate i n t o an area i n l a r g e herds of from t en to one hundred thousand which would - 67 -r e s u l t i n a l a r g e consumption of forage. Hares, ground s q u i r r e l s and m i c r o t i n e s p e r i o d i c a l l y become abundant and could consume a l a r g e p r o p o r t i o n of the a v a i l a b l e forage (Thompson, 1955, P i t e l k a , 1957)* U n t i l consumption of forage by a l l h e r b i v o r s i s q u a n t i f i e d , however, i t w i l l not be pos-s i b l e to assess the degree of i n t e r s p e c i f i c competition which may e x i s t . - 68 -D i s t r i b u t i o n The current d i s t r i b u t i o n of muskoxen i n Canada, together w i t h estimates of numbers, has r e c e n t l y been published by Tener (1958). Since i n f o r m a t i o n subsequent to the p u b l i c a t i o n of the l a t t e r paper has been r e c e i v e d , a l l of the d i s t r i b u t i o n a l data have been in c o r p o r a t e d i n t o t h i s r e p o r t . H i s t o r i c a l records i n d i c a t e t h a t muskoxen were not abundant i n A r c t i c Canada even before f i r e a r m s and f u r t r a d i n g were i n -troduced. P r i o r to 1862, when muskox hides were f i r s t " , s o l d a t t r a d i n g p osts, t r a v e l e r s i n the A r c t i c , such as Hearne (1795), F r a n k l i n (1823) and Back (1836) recorded seeing what they some-times termed "numerous 1 1 muskoxen* However, the d a i l y records published i n t h e i r books suggest t h a t they never encountered herds numbering i n the hundreds, or even many small groups d a i l y , but r a t h e r o n l y s o l i t a r y b u l l s o r a few small bands. MacFarlane (1905) confirmed t h i s when he remarked t h a t he observed very few muskoxen on any of h i s s e v e r a l s p e c i m e n - c o l l e c t i n g t o u r s and h i s many summer and wi n t e r journeys w i t h i n the A r c t i c C i r c l e i n the 1850's. I t should be borne i n mind, too, t h a t observers t r a v e l i n g along r i v e r systems i n summer may get an exaggerated impression of the number of muskoxen i n the country, because a t t h a t season they u s u a l l y frequent the r i v e r v a l l e y s t o feed on the l u s h w i l l o w and other p l a n t growth. Former D i s t r i b u t i o n The combined e f f e c t of f u r t r a d i n g and fi r e a r m s d r a s t i c a l l y reduced muskox numbers and d i s t r i b u t i o n . Hudson's Bay Company re t u r n s provide f i g u r e s of the minimum k i l l from 1862, when hides * 69 -were f i r s t traded, u n t i l 1 9 1 6 , one year before complete p r o t e c t i o n was given to the s p e c i e s . During t h a t p e r i o d , more than 1 5 , 0 0 0 s k i n s were traded by the Company. I t i s known th a t many a d d i t i o n a l muskoxen were k i l l e d by whalers and e x p l o r e r s , and by na t i v e s f o r t h e i r own needs, both on the A r c t i c mainland and on the A r c t i c i s l a n d s . Hewitt ( 1921 ) p u b l i s h e d a few records of muskox s k i n s traded by the Hudson's Bay Company; but as there are d i s c r e p a n c i e s between h i s f i g u r e s and Company records r e c e n t l y f u r n i s h e d , the l a t t e r f i g u r e s are given i n Tables XVII and X V I I I . The Company's records were generously made a v a i l a b l e f o r p u b l i c a t i o n by the Secretary of the Hudson's Bay Company, London, through the kindness of Mr. Charles E l t o n of the Bureau of Animal P o p u l a t i o n , Oxford U n i v e r s i t y , where the records are l o c a t e d . Table XVII i s a l i s t . o f muskox s k i n s r e c e i v e d from the Athabasca, Mackenzie, Cumberland, C h u r c h i l l , and York Factory D i s t r i c t s i n the years 1 8 6 2 - 1 8 9 2 and 1 8 9 6 - 1 9 0 0 . The a d m i n i s t r a t i v e boundaries of the Company's f u r t r a d i n g d i s t r i c t s underwent s e v e r a l changes throughout the muskox hunting p e r i o d of 1 8 6 2 r 0 . 9 l 6 . These changes have been recorded by E l t o n and Nicholson (1942) ' and the reader d e s i r i n g d e t a i l s i s r e f e r r e d to them, a s the present author has used t h e i r r e v i s e d d i s t r i c t s . Table X V I I I records the number of s k i n s s o l d i n the r e v i s e d d i s t r i c t s i n the years 1 9 0 1 - 1 9 1 6 . The records suggest t h a t most of the s k i n s traded came from three main regions on the A r c t i c mainland of Canada: from between Great Bear Lake and the A r c t i c coast at l e a s t 2 , 2 1 6 s k i n s and from between Great Slave Lake and Bathurst I n l e t at l e a s t 1 , 1 7 2 s k i n s - 70,-were bought i n the p e r i o d from 1862 to 1885• I n those two reg i o n s , d u r i n g the whole of the two periods covered by the re c o r d s , a minimum of 8,564 s k i n s were traded. I n the r e g i o n , from Chester-f i e l d I n l e t n o r t h t o the base of Boothia P e n i n s u l a , more than 3,300 hides were turned i n durin g the same two pe r i o d s . Table XVII Hudson's Bay Company, muskox f u r r e t u r n s . 1862-1900  Year Athabasca Mackenzie Cumberland C h u r c h i l l York T o t a l s D i s t r i c t D i s t r i c t D i s t r i c t D i s t r i c t Factory D i s t r i c t 1862 20 20 63 — 14 Ma — mm 14 64 mm mm 14 mm mm - - 14 65 — 25 «•« 66 91 66 — mmmm 1 1 67 — 10 4 14 68 9 — 68 wm mm 77 69 — _ 18 4 22 1870 — 18 - - 6 — 24 71 m*mm 6 — 1 — 7 72 28 1 26 — 55 73 8 4 12 74 ... 8 mm^e 2 wmma 10 75 <*•— 14 - - 113 127 76 mmm» 112 3 •mm» 115 77 — 218 — 177 mmmm 395 78 468 mnmm 52 « M « M 520 79 1 556 mmmm 21 mm mm 578 1880 37 501 13 551 81 7 356 mm mm 14 377 82 — - 239 •mmm 75 314 83 2 233 — _ 31 - - 266 84 2 239 17 138 mmmm 396 85 14 308 — 63 — 385 86 1 318 — — — — 319 87 5 246 24 161 436 88 163 1,004 33 — 69 1,269 89 234 934 55 — 147 1,370 1890 423 762 50 446 1,681 91 250 384 38 416 1,088 1892-96 (Only record: P r i n c e A l b e r t , 3) 486 97 51 135 140 mm mm 157 98 40 208 116 — - 146 510 99 266 163 MB mm 79 508 1900 .... 140 28 145 313 TOTALS 1 ,230 7,809 665 888 1,770 12,365 71 ~ During the period of most successful muskox hunting, from 1888 to 1891, the Company's records show that of 5,408 hides traded, 3,084 were from the Mackenzie District, 1,078 from York Factory, 1,070 from the Athabasca Di s t r i c t and 176 from Cumberland D i s t r i c t . Unfortunately, detailed records for the Mackenzie River D i s t r i c t are available only unti l 1885, so i t i s not pos-sible to state definitely what post contributed the most skins after that date. Probably the majority of them were traded at Fort Rae, as the Indians trading into that post ranged far out on the barrens i n a northeasterly direction to east of the Copper-mine River, beyond Point Lake (Russell, 1898). Table XVIII Hudson's Bav CQomr. >anv. muskox i ?ur returns. 1901-1916 Year Athabasca Mackenzie R. Saskatchewan Keewatin Nelson R. Totals Dis t r i c t D i s t r i c t D i s t r i c t D i s t r i c t District 1901 25 125 58 42 mm mm 250 02 — 147 74 74 — 295 03 1 27 41 66 — 135 04 -- 44 48 22 114 05 — — — 26 11 37 06 2 110 — 112 07 mm mm 54 35 10 — — 99 03 -- 55 13 5 78 09 — 37 — 37 74 1910 8 81 130 32 251 11 — 94 — — 58 152 12 — 43 66 mm mm 171 280 13 — 2 —— -- 145 147 14 — 18 — 18 15 — 5 — — 77 82 16 — 1 — -- — 1 TOTAL' > 34 735 606 299 451 2,125 That the intensive hunting had a serious effect on muskox numbers i s demonstrated i n Tables XVII and XVIII, In successive years, the number of skins brought diminished rapidly. The native hunters had to t r a v e l f a r t h e r i n t o the barrens each year to f i n d the animals ( R u s s e l l , op. c i t . ) . I n the r e g i o n between Great Bear Lake and the A r c t i c coast, the species was v i r t u a l l y exterminated, although a small remnant p o p u l a t i o n undoubtedly p e r s i s t e d i n the Horton R i v e r area. Muskoxen were a l s o e l i m i n a t e d i n much of the country north and northeast of Great Slave Lake. There, too, how-ever, remnant populations found s a f e t y — i n the rough h i l l y country west and southwest of Bathurst I n l e t and along the Thelon R i v e r . In the l a t t e r area, Eskimos and Indians penetrated l e s s deeply f o r f e a r of encountering each other. The r e g i o n between C h e s t e r f i e l d I n l e t and Boothia Peninsula i s as yet l i t t l e known but the species d i d s u r v i v e t h e r e . Recent o c c a s i o n a l t r a v e l l e r s i n t h a t r e g i o n have seen as many as 40 muskoxen at a time. In summary, when muskox hunting was made i l l e g a l i n 1917, the species on the A r c t i c mainland had been g r e a t l y reduced i n numbers from i t s abundance of former days and was r e s t r i c t e d i n d i s t r i b u -t i o n to three major r e f u g i a — t h e Bathurst I n l e t r e g i o n , the Thelon Game Sanctuary, and the base of Boothia P e n i n s u l a . There were other s i t e s where muskoxen found some measure of s e c u r i t y , such as i n the Horton R i v e r r e g i o n mentioned above and the h i l l s northeast of Lake Cl i n t o n - C o l d e n . S i g h t i n g s i n recent years i n areas other than the above .undoubtedly r e f l e c t the expansion and reoccupation of former ranges. The mainland p o p u l a t i o n was estimated by R.M. Anderson (1930) to be 500 animals. Hone (1934) c o l l e c t e d the records of extermination or deple-t i o n of muskoxen f o r most of the i s l a n d s i n the Canadian A r c t i c . A summary of the i n f o r m a t i o n f o l l o w s , i n c l u d i n g a number of Anderson's estimates. - 73 -On Banks Is l a n d the l a s t s i g h t - a n d - k i l l record was of a herd shot by Eskimos i n the southeast corner of the i s l a n d i n 1911. They were b e l i e v e d to be the l a s t of the species on the i s l a n d . On V i c t o r i a I s l a n d , i n s p i t e of hunting by n a t i v e and probably whalers, remnant herds were reported northeast of P r i n c e A l b e r t Sound, at the time of p r o t e c t i o n i n 1917. Anderson's estimate was 20 muskoxen. Hone (1934) quotes Anderson's estimates of 1,500 muskoxen on P r i n c e of Wales Is l a n d and none on Somerset I s l a n d . M e l v i l l e I s l a n d , one of the newly named group of Queen E l i z a b e t h I s l a n d s , had been drained of many muskoxen by e x p l o r e r s , from the time of Captain W.E. Parry i n 1819-20. More than 600 were k i l l e d between then 1917. Storkersen (1920) stated that about 4,000 muskoxen were present on that i s l a n d . Anderson's estimates of numbers of muskoxen, on Bathurst and C o r n w a l l i s I s l a n d s , were 1,500 and 200, r e s p e c t i v e l y . Devon I s l a n d supported a small population of muskoxen, p a r t i c -u l a r l y along the north coast. There had been some u t i l i z a t i o n of the s p e c i e s , but the 1930 population estimate was 200. Muskoxen on A x e l Heiberg I s l a n d have been r a r e l y hunted, except at i r r e g u l a r i n t e r v a l s by e a r l y e x p l o r e r s and probably by Eskimos who crossed Ellesmere I s l a n d from Greenland. Anderson estimated that there were 1,000 of the ungulates on A x e l Heiberg i n 1930. U t i l i z a t i o n of muskoxen on Ellesmere Island predates h i s t o r i -c a l records. The ancient Eskimo campsites near Bache Pe n i n s u l a c o n t a i n many muskox remains. No s i g n i f i c a n t inroads i n t o t h e i r numbers were made u n t i l p o l a r e x p e d i t i o n s , c h i e f l y American, k i l l e d - 74 -s e v e r a l hundred f o r food f o r themselves and t h e i r dogs, before and a f t e r the t u r n of the century. Greenland Eskimos armed w i t h r i f l e s a l s o k i l l e d many. Using i n f o r m a t i o n from explorers and the R.C.M. P o l i c e , Anderson estimated 4,00(||muskoxen on the i s l a n d i n 1930. There i s no h i s t o r i c a l i n f o r m a t i o n about muskox numbers on the i s l a n d s of the P a r r y group north of M e l v i l l e I s l a n d , apart from the record o f Capt. F.L. M'Clintock, who k i l l e d f i v e on P r i n c e P a t r i c k I s l a n d i n 1857*59• There are no records, e i t h e r , o f muskoxen ever having occurred on B a f f i n I s l a n d . Lacking i n -formation, Anderson formed no p o p u l a t i o n estimates f o r those islands. On the A r c t i c i s l a n d s , the h i s t o r y of muskoxen f o l l o w s a p a t t e r n s i m i l a r to t h a t of t h e i r mainland r e l a t i v e s : e x p l o i t a t i o n i n some areas, extermination i n other s , and r e l a t i v e s e c u r i t y i n regions too remote f o r human t r a v e l . Present D i s t r i b u t i o n A r c t i c mainland^ The accumulated data obtained from the numerous sources d e t a i l e d i n the procedures s e c t i o n , are not n u m e r i c a l l y i n d i c a t i v e , as most s i g h t i n g s were f o r t u i t o u s . I t cannot be assumed th a t a l l animals v i s i b l e to the observers were counted, as sustained observa-t i o n of the ground during f l i g h t i s not u s u a l , except by those undertaking s p e c i f i c surveys. However, the data are va l u a b l e f o r records of d i s t r i b u t i o n , and sometimes provide the only i n d i c a t i o n t h a t muskoxen e x i s t i n a r e g i o n . Muskoxen have been reported from many areas on the mainland, but concentrations are evident i n the Thelon Game Sanctuary and i n - 75 * Bathurst I n l e t r e g i o n . Herds occur i n l e s s e r numbers i n other l o c a l e s d escribed below. F i v e summer survey ground p a r t i e s have v i s i t e d the Thelon Game Sanctuary i n recent years. I n 1951 and 1952, survey crews of the Canadian W i l d l i f e S e r v i c e counted 334 and 169 muskoxen, respec-t i v e l y . I n 1954, a pa r t y of the Topographical Survey, Department of Mines and T e c h n i c a l Surveys, counted 170. A l l three p a r t i e s travelled by canoe and saw the muskoxen from the canoes or when t r a v e l l i n g on f o o t away from the r i v e r . The other two p a r t i e s were personnel of the G e o l o g i c a l Survey of Canada surveying from h e l i c o p t e r s . I n the summer of 1954, the p o r t i o n of the sanctuary l y i n g i n the D i s t r i c t of Keewatin was examined, and 33 muskoxen were observed. I n 1955, the s u r v e y T s a e r i a l a c t i v i t i e s were continued west of the boundary between Mackenzie and Keewatin D i s t r i c t s and 156 muskoxen were counted. From what i s known of muskox d i s t r i b u t i o n and movements i n the sanctuary, i t i s u n l i k e l y t h a t the 1954 count from the a i r d u p l i -cated t h a t i n 1955, and thus a t o t a l of 189 muskoxen was observed from h e l i c o p t e r s . I n l a t e March, 1956, the author counted the muskoxen i n the eastern h a l f of the sanctuary and recorded 192 of them. None of the counts, e i t h e r from the ground or 4 from the a i r , can be regarded as a b s o l u t e . However, i t i s s i g n i f i c a n t t h a t s i n c e 1952 the t o t a l numbers seen have ranged between 169 and 192, and t h a t the high count of 334 i n 1951 has not s i n c e been e q u a l l e d . Q uite probably the 1951 count i n c l u d e d most of the muskoxen i n the * 76 -sanctuary. Based on a l l of these observations and c o n s i d e r a t i o n s , the estimate of the present p o p u l a t i o n i n the sanctuary i s placed a t 350* The second r e g i o n of comparative abundance i s the country between the Tree R i v e r and Bathurst I n l e t and south of the I n l e t to about the headwaters of the eastern f o r k of the Burnside R i v e r . Herds are known to e x i s t near the Burnside, Hood, Wright, James, and Tree R i v e r s , and near Gray's Bay and D a n i e l Moore Bay. Numbers i n v o l v e d i n the herds seen were as high as 50. A systematic cov-erage of the r e g i o n by a i r has not yet been undertaken; the c l o s e s t approximation to one was a survey f l i g h t made by R. Smith of the U.S. F i s h and W i l d l i f e S e r v i c e , who f l e w across the r e g i o n on a waterfowl survey i n J u l y , 1950. He recorded 209 muskoxen. An estimate of the t o t a l numbers i n the area i s 450. The Hudson Bay muskox (0. m. niphoecus) was considered by A l l e n (1913) to occupy, as p a r t of i t s range, the northern h a l f of Keewatin D i s t r i c t , north of C h e s t e r f i e l d I n l e t . Recent r e p o r t s from t h a t area are few, p a r t l y because fewer t r a v e l e r s pass through i t and p o s s i b l y because of the s c a r c i t y of muskoxen. Father Vander-b i l t r e p o r t e d t h a t the E l l i c e H i l l s had "some" muskoxen i n 1944 and, i n 1946, he s t a t e d t h a t the Hayes R i v e r supported at l e a s t 40. I n 1948 the l a t e Gunnar I n g e b r i t s o n saw 50 muskoxen a t the base of Simpson Peninsula ( B a n f i e l d , 1951), and i n 1949 the l a t e Father B u l i a r d reported seeing a muskox near Garry Lake. "Sandy™ Lunan, Hudson's Bay Company former post manager at Baker Lake, reported t h a t i n the s p r i n g of 1952 about 50 muskoxen were observed on the Meadowbank R i v e r . Eskimos reported t r a c k s north of C h e s t e r f i e l d - 77 -I n l e t i n the w i n t e r of 1954-55• The l a t e s t evidence comes from Andrew MacPherson (pers. corresp.) who obtained muskox informa-t i o n from Eskimos and the r e s i d e n t missionary of P e l l y Bay i n the summer of 1956. P r e c i s e f i g u r e s were not a v a i l a b l e , but the i n -formation i n d i c a t e d t h a t the animals were q u i t e common i n the country between the Hayes and Murchison R i v e r s as w e l l as at the head of Committee Bay. An a e r i a l survey of the country described above was undertaken i n l a t e March, 1957, but no muskoxen were observed. I n the western A r c t i c , muskoxen have been si g h t e d i n s e v e r a l w i d e l y s c a t t e r e d l o c a l i t i e s n orth o f t r e e l i n e . I n 1949, the R.C.A.F. reported seeing a herd of ten i n the Bluenose Lake area north of Great Bear Lake. Herds were s i g h t e d i n the same area by J.P. . K e l s a l l i n 1953, when he saw 86, and again i n February, 1955. During the spr i n g and summer of 1953, Eskimos t o l d J.K. Fr a s e r that they had seen a t o t a l of 39 muskoxen about 25 m i l e s south of Paulatuk. There have been recent r e p o r t s of muskoxen southwest of Contwoyto Lake. I n the wi n t e r of 1953-54, Eskimos saw 30 to 40 there and i n December, 1955, a herd of 12 was observed i n th a t l o c a l i t y by J.P. K e l s a l l . Other p o i n t s where muskoxen have been seen i n c l u d e : Lake Cl i n t o n - C o l d e n , where herds were seen i n 1952 and 1955; Regan Lake, where a herd of 19 was observed i n 1955; Tourgis Lake, where 40 were seen i n 1951 and two i n 1955; the east end o f Beechy Lake, where three herds were observed by a G e o l o g i c a l Survey pa r t y i n 1955; the Warren R i v e r area where two herds were seen by the Survey * 78 * p a r t y and three b u l l s by the author, a l s o i n 1955; and south of MacAlpine Lake, where two were observed i n December, 1955, by J.P. K e l s a l l . Based on the above i n f o r m a t i o n , the mainland p o p u l a t i o n i s estimated to be about 1,500, A r c t i c i s l a n d s . Figures of muskoxen on the A r c t i c i s l a n d s are much more ten-t a t i v e than f o r those on the mainland. The observations f o r each i s l a n d g e n e r a l l y are few and i n most cases i n v o l v e r e l a t i v e l y few animals. The R.C.A.F. s u p p l i e d most of the s i g h t i n g s and, unless otherwise i n d i c a t e d , the ensuing observations are t h e i r s . O f f i c e r s of the R.C.M. P o l i c e and members of other government departments c o n t r i b u t e d s i g n i f i c a n t records, however, and these are c r e d i t e d i n d i v i d u a l l y . Each i s l a n d f o r which records are a v a i l a b l e i s considered s e p a r a t e l y i n the f o l l o w i n g d i s c u s s i o n . I s l a n d s which are omitted, such as King W i l l i a m , and Borden, have had no recent muskox records. Muskoxen have never been reported i n h i s t o r i c a l times from B a f f i n I s l a n d or the adjacent M e l v i l l e P e n i n s u l a . A x e l Heiberg: F i f t y muskoxen were reported from the east-c e n t r a l p a r t of the i s l a n d i n the summer of 1950, 30 from opposite Fosheim P e n i n s u l a , 10 i n l a n d from Mokka F i o r d i n J u l y , 1953, and 30 from the same area i n A p r i l , 1955. S.D. MacDonald (pers. corresp.) secured some e x c e l l e n t records from the e a s t - c e n t r a l s e c t i o n w h i l e engaged i n f i e l d work f o r the N a t i o n a l Museum of Canada i n 1955. During two f l i g h t s over the area on May 13, 139 muskoxen were counted, i n c l u d i n g s e v e r a l c a l v e s . On J u l y 19, f o u r were seen southeast of White Mountain and two herds, of 17 and 14, r e s p e c t i v e l y , were g r a z i n g on Schei P e n i n s u l a . The - 79 -total muskox population of the island i s tentatively placed at 500, Banks Island: The f i r s t observation for many years of a musk-ox on this island was obtained by T.H. Manning (1953) who saw one on September 2, 1952, i n the Thomsen River valley. Two were reported by the R.C.A.F. i n 1953, In the summer of 1954, a h e l i -copter crew from the U.S.S. Burton Island reported seeing 30 i n the northwest section of the island, McEwen (MS report, 1956) stated that i n 1954 Eskimos saw two along the Masik River i n April, two at Sacks Harbour i n June and one at Storkerson Bay in December, Muskoxen may possibly have crossed from Melville Island to Banks Island (after 1911) and repopulated i t , but i t i s more probable that remnant herds or individuals remained i n security i n the northern end of the island. Possibly 100 or more muskoxen li v e on Banks Island today, Bathurst Island: Small herds of from 6 to 30 have been reported from central and southwest Bathurst Island, There are as yet no records from the northern section of the island. The total number on the island i s estimated to be about 100. Cornwallis Island: Cornwallis Island supports a small popula-tion of muskoxen. Numbers reported since 1952 have varied between 3 and 47. More than three herds have never been recorded at a time. There i s a suggestion that the animals on the island have a marginal existence: an adult cow was found dead from what was believed to be starvation. The population estimate for the island i s about 50. Devon Island: Herds have been reported specifically from Grinnel Peninsula, Viks Fiord, Cape Sparbo, Dundas Harbour, Croker * 80 -Bay and Erebus Bay, but probably there are herds i n other p a r t s of the i s l a n d as w e l l . Much of the eastern h a l f of the i s l a n d i s covered w i t h g l a c i e r s , reducing the t o t a l p o t e n t i a l muskox range. Present i n f o r m a t i o n suggests t h a t the muskox po p u l a t i o n on Devon I s l a n d i s about 200, but t h i s may be a minimum f i g u r e , E g l i n t o n I s l a n d : Small herds were s i g h t e d i n the northern h a l f of the i s l a n d i n the s p r i n g and autumn of 1952, Those animals probably are r e s i d e n t t h e r e , although i t i s q u i t e l i k e l y t hat there I s some interchange across the i c e w i t h P r i n c e P a t r i c k , E g l i n t o n , and M e l v i l l e I s l a n d s . A t e n t a t i v e p o p u l a t i o n estimate i s 30 musk-oxen. Ellesmere I s l a n d : This i s l a n d supports probably the l a r g e s t p o p u l a t i o n of muskoxen i n Canada, p a r t l y because of i t s s i z e and p a r t l y because i t s low h i l l s and p l a i n s form s u i t a b l e range. Records i n d i c a t e t h a t most of the herds on the i s l a n d are on the west s i d e where good range i s most extensive. Muskoxen have been reported from C r a i g Harbour west to Goose F i o r d , and north to Vendome, Baumann Bay, Canon and Greely Fjords, Fosheim P e n i n s u l a , the Lake Hazen country and the northern t i p of the i s l a n d i n the v i c i n i t y of Cape Joseph Henry, Cape Sheridan and M»Clintock Bay. Major concentrations have been seen on Fosheim P e n i n s u l a , where 413 were counted i n 1950, and i n the Lake Hazen country, where the R.C.A.F. s i g h t e d 200 i n A p r i l , 1956. Herds seen i n other areas noted above contained 30 to 40 i n d i v i d u a l s . Recent records f o r the eastern s i d e of the i s l a n d are notably l a c k i n g , but i t i s known t h a t there are muskoxen on Bache Peninsula and near Archer F i o r d . The g e n e r a l l y mountainous and g l a c i a l nature * 81 * o f the northern and eastern p o r t i o n s of the i s l a n d makes, them l e s s d t u i t a b l e ranges than the western p a r t . As w i t h the other i s l a n d s , i t i s d i f f i c u l t t o estimate the t o t a l p o p u l a t i o n of muskoxen on Ellesmere, but 2,000 i s b e l i e v e d t o be a reasonable f i g u r e , Graham I s l a n d : A herd of 30 was seen on t h i s i s l a n d i n the autumn of 1952 and s m a l l e r herds were reported there i n the summers of 1953 and 1954, E a r l i e r r e p o r t s of muskoxen on the i s l a n d , t o -gether w i t h those above, i n d i c a t e a r e s i d e n t p o p u l a t i o n of about 30, w i t h - some movement across to Ellesmere I s l a n d , E l l e f Ringnes I s l a n d : I n the s p r i n g of 1949, the R,C,A,F. si g h t e d 21 muskoxen on the i s l a n d , the f i r s t record f o r the species t h e r e . Resident weather s t a t i o n personnel reported t h a t an a d u l t b u l l , a cow and a y e a r l i n g c a l f were near the s t a t i o n i n 1951, S.D. MacDonald of the N a t i o n a l Museum of Canada t o l d me that no muskoxen were seen by him on E l l e f Ringnes I s l a n d i n 1954, but b i t s of wool, droppings and o l d t r a c k s i n d i c a t e d that they d i d appear there o c c a s i o n a l l y . No p o p u l a t i o n estimate can be given w i t h the l i m i t e d data a v a i l a b l e at present, M e l v i l l e I s l a n d : Herds of muskoxen have been si g h t e d at wide-l y separated places on t h i s i s l a n d , i n c l u d i n g Sabine P e n i n s u l a , B r i d p o r t I n l e t , Winter Harbour, Dundas Peninsula and the western h i l l y p o r t i o n of the i s l a n d near Purchase Bay, The numbers i n v o l v e d were s m a l l , ranging from 3 to 30, The animals appear to be r e l a -t i v e l y more numerous near the head of Liddon G u l f , where three herds t o t a l i n g 70 were reported on March 2 9 , 1952, A p r e l i m i n a r y estimate o f the t o t a l numbers on the i s l a n d i s 200, - 82 A muskox survey of M e l v i l l e I s l a n d was undertaken i n 1953, when A.G. Loughrey f l e w 700 m i l e s i n an R.C.A.F. a i r c r a f t over the i s l a n d . None of the animals was seen on the survey. P r i n c e P a t r i c k I s l a n d : Most of the recent records of muskoxen seen on t h i s i s l a n d have been centered around Mould Bay where a weather s t a t i o n i s l o c a t e d . The numbers i n herds observed have ranged from 3 to 31. P r i n c e P a t r i c k I s l a n d has no g l a c i e r s but much of the i s l a n d appears to be u n s u i t a b l e muskox range. Reports of dead animals have been r e c e i v e d from weather s t a t i o n personnel and from s c i e n t i f i c i n v e s t i g a t o r s , S.D. MacDonald and Andrew Macpherson, who worked out from Mould Bay. These observers a t t r i b u t e d the deaths to wolf p r e d a t i o n and n a t u r a l causes. I t i s p o s s i b l e t h a t s t a r v a t i o n because of range o v e r u t i l i z a t i o n was a c o n t r i b u t i n g f a c t o r . During the summer of 1958, Dr. Ri - T h o r s t e i n -son .of G e o l o g i c a l Survey of Canada undertook a complete g e o l o g i c a l reconnaissance of the i s l a n d by h e l i c o p t e r and saw." o n l y three musk-oxen. I t i s d i f f i c u l t to assess the t o t a l number of muskoxen on the i s l a n d but a minimum estimate i n the l i g h t of the most recent i n -formation i s 25. P r i n c e of Wales I s l a n d : The R.C.M. P o l i c e were t o l d by some Eskimos who v i s i t e d the i s l a n d i n the w i n t e r of 1951-52, t h a t they saw "a few" muskoxen. Mr. T.H. Manning and Mr. A.H. Macpherson undertook a b i o l o g i c a l reconnaissance of the i s l a n d during the summer of 1958 and reported seeing 83 muskoxen there, the f i r s t f a c t u a l . r e p o r t i n recent times. Probably at l e a s t 100 of the animals are on the i s l a n d . - 83 -Somerset I s l a n d : i There are two recent records o f muskoxen ob-served on the i s l a n d , both f o r the pe r i o d 1950-53* The f i r s t r e c o r d was of a herd s i g h t e d at Cr e s w e l l Bay; the second, an Eskimo r e p o r t t h a t they saw "many" on the northern p a r t of the i s l a n d , A popula-t i o n estimate cannot be given but i t i s p o s s i b l e t h a t there are s e v e r a l hundred muskoxen on the i s l a n d . Stefansson I s l a n d : On J u l y 22, 1954, two a d u l t s were observed by V.E.F. Solman on the northeast s e c t i o n of the i s l a n d . V i c t o r i a I s l a n d : Three muskoxen, and p o s s i b l y more, were sighted on southern V i c t o r i a I s l a n d , i n the summer of 1958, by Eskimos. During the summer of 1959, Dr. R. Thornsteinsson Ts p a r t y covered much of the i s l a n d by l i g h t a i r c r a f t , seeing 76 muskoxen. Based on the percentage of the i s l a n d be covered, Macpherson (pers. comm.) has estimated t h a t t h e r e are about 670 muskoxen on V i c t o r i a I s l a n d . I t i s not p o s s i b l e to form an accurate determination o f muskox numbers on the A r c t i c i s l a n d s of Canada. The i n f o r m a t i o n a v a i l a b l e a t present, however, suggests t h a t about 3,500 animals are l i v i n g there* Herd S i z e and Composition P o p u l a t i o n data have been obtained from muskoxen from two p r i n -c i p a l areas, the Thelon Game Sanctuary and Lake Hazen, Ellesmere I s l a n d . A d d i t i o n a l data are a v a i l a b l e from Fosheim Pe n i n s u l a s t u d i e s by the w r i t e r (Tener, 1954). A l l the above i n f o r m a t i o n i n c l u d e s age and sex c a t e g o r i e s , whereas i n f o r m a t i o n obtained from other sources, w h i l e v a l u a b l e , i s not as complete as i t u s u a l l y l i s t s e i t h e r t o t a l counts, or t o t a l and c a l f counts. D u p l i c a t i o n i n counts has been avoided as f a r as p o s s i b l e . A p o p u l a t i o n of muskoxen i s defined here as the t o t a l number of i n d i v i d u a l s of the species e x i s t i n g w i t h i n a g e o g r a p h i c a l l y d e f i n e d *• 84 «•• a r e a . The Thelon p o p u l a t i o n , f o r example, i n c l u d e s a l l muskoxen w i t h i n the boundaries of the Thelon Game Sanctuary and the Lake Hazen p o p u l a t i o n i n c l u d e s a l l muskoxen w i t h i n 20 m i l e s of the shores of the l a k e . I t must be r e a l i z e d t h a t there are no t o t a l p o p u l a t i o n counts f o r any l a r g e area. I n a l l cases v a r y i n g proportions of the populations have been sampled e i t h e r by a e r i a l or ground survey. I n some of these cases, t h e s a m p l i n g has been done a t random, i n others not, depending on the mode of t r a v e l a v a i l a b l e to the observer. Po-p u l a t i o n estimates have been deri v e d from those surveys. At best, a e r i a l surveys.' y i e l d e d t o t a l numbers of animals i n herds i n c l u d i n g the number of c a l v e s . I n some i n s t a n c e s , however, no r e l i a b i l i t y could be placed on c a l f counts from the a i r because of the tendency of the herd animals t o bunch when f r i g h t e n e d by an a i r c r a f t . Calves could not be seen under those circumstances. Some a e r i a l c a l f counts were u s e f u l checks a g a i n s t ground o b s e r v a t i o n s , however, when tha t r e s e r v a t i o n was kept i n mind. Herd counts, then, were obtained from both a e r i a l and ground ob s e r v a t i o n s . Age and sex categ o r i e s f o r the most p a r t were obtained from ground s t u d i e s alone, Thelon Game Sanctuary Muskox observations i n the Thelon Game Sanctuary between 1951 and 1957, i n d i c a t e d i n Tables XIX to XXII , have been drawn from a number o f sources. Those sources are K e l s a l l (1951, 1953, 1955), Teal (1954), G e o l o g i c a l Survey of Canada (1955) and my own observa-t i o n s . - 85 -Table XIX Muskoxen Herd S i z e Frequency, A e r i a l and Ground Observations. Thelon Game Sanctuary. N.W.T. Summer Observations Winter Observations. 1951. «52. «55. «57 % M S . »56 * Herd S i z e No.of Obs. % of Obs. Herd S i z e No. of Obs.. % of Obs. 1 109 55.8 1 2 8 2 18 9.2 2 1 4 3 5 2.6 3 2 8 4 3 1.6 5 1 4 5 7 3.6 7 2 8 6 6 3.1 9 2 8 7 3 1.6 11 1 4 8 5 2.6 12 1 4 9 2 1.0 16 1 4 10 2 1.0 17 4 16 11 7 3.6 22 2 8 12 3 1.6 23 1 4 13 2 1.0 24 2 8 14 2 1.0 30 1 4 15 1 .5 38 1 4 17 3 1.6 52 1 18 1 .5 19 3 1.6 25 100 20 4 2.0 21 2 1.0 22 1 .5 28 1 .5 29 1 .5 31 1 .5 38 1 .5 40 1 .5 42 1 .5 195 100.0 -- 86 -Mo. o f muskoxen oer hfird - 87 -Table XIX gives the herd s i z e frequencies obtained by ground and a e r i a l observations i n summer and wi n t e r * The observations of a l l years have been grouped by season, and those data p l o t t e d on the graph, F i g u r e 5. The graph and t a b l e show the great d i f f e r e n c e i n the number of observations of s o l i t a r y animals between summer and wint e r * During the former season 109, or 55.8 per cent, of the observations were of s o l i t a r y animals w h i l e d u r i n g the w i n t e r season two, or eigh t per cent, of the observations were of s i n g l e muskoxen. There was l i t t l e v a r i a t i o n i n the frequency of observations of herds of s i z e s l a r g e r tham f o u r animals except f o r the number of wi n t e r observations of herds of 17 animals. S i x t e e n per cent of a l l w i n t e r s i g h t i n g s were of t h a t herd s i z e . The average herd s i z e each year i n summer, as shown i n Table XX, v a r i e d between nine and 1$ muskoxen per herd, w i t h a mean herd s i z e of 10.78. I n w i n t e r , average herd s i z e each year v a r i e d between 10 and 24 animals, w i t h a mean of 16.87. The l a r g e s t herd i n summer contained 42 animals and i n winter 52. - 88 -Table XX Average Herd S i z e , A e r i a l and Ground Observations, Thelon Game Sanctuary. 1951 - 1957  Season Year Observer S o l i t a r y B u l l s No, of Herds T o t a l No, i n Herds -* Av, No i n Herds Summer 1951 K e l s a l l 30 35 280 8 Observ . 1952 Tener 24 a 145 18 1955 Tener 3 5 82 17 1955 Teal 38 7 90 : 13 1954-55 Geol, Survey 8 20 225 11 1957 Tener 6 7 62 9 Winter Observ, 1953 K e l s a l l 1 6 61 10 1955 K e l s a l l 0 9 136 15 1956 Tener 1 8 191 24 •Figures to nearest whole animal. T o t a l numbers seen each year d i f f e r e d , because of herd movements, d i f f e r e n t p r oportions of the Sanctuary surveyed, d i f f e r e n t methods of t r a n s p o r t a t i o n used and p o s s i b l y because the e f f i c i e n c y of the observers d i f f e r e d . I n many cases, as..previously mentioned, i t was not p o s s i b l e to d i s t i n g u i s h a l l age c l a s s e s i n herds observed, p a r t i c u l a r l y a d u l t eows and immature muskoxen. I n l a r g e herds, w i t h m i l l i n g animals, or w i t h d i s t a n t groups, aging i s d i f f i c u l t or i m p o s s i b l e . Such segregations as were p o s s i b l e to make of the muskoxen observed i n the Sanctuary are given i n Table XXI, Table XXI Muskox Herd Ground Segregations. Thelon Game Sanctuary  Year July - Aug. 1951 July - Aug, 1952 Aug. 1955 Aug. 1955 A l l im April 1956 Observer J.P. Kelsall JJ3. Tener J.S, Tener 4.J.Tea! J.S.Tener No, of Herds 8 5 7 12 2 Adult Bulls 20 12 10 22 5 Adult Cows 52 16 16 , 32 26 Adult & Immat. 224 15 31 48 79 Immatures 27 14 14 33 Yearlings 12 3 4 7 4 Yearling 8.3 percent 3.7 4.4 4.C 5.9 Calves 30 19 6 12 1* 0 Calf percent 11.d 13.1 7.3 13.3 10.; I 0 Cow calf ratk l:.32 Total 254 145 82 90 lfa 68 The proportion of bulls to total numbers seen i n the years 1952 and 1955 was nearly the same, 1:7.25 and 1:7.8 respectively. The winter observations of April, 1956, indicates a lower pro-portion of bulls, but this may have been a result of too small a sample of the population on the winter range. Aerial counts are given i n Table XXII. - 90 Table XXII Muskox Herd A e r i a l Observations. Thelon Game Sanctuary Tear March 1953 July-Aug. 1954 May 1955 March 1956 J u l y 1957 Observer No. of Herds A d u l t s & Immat, Y e a r l i n g s Y e a r l i n g percent Calves C a l f percent JJ?. Kelsall 6 55 6 9.8 K e l s a l l & Teal 22$ 38 14.3 J.P. K e l s a l l 8 130 6 4.4 J ^ . Tener 8 179 12 6.3 J.S. Tener 7 59 4 6.3 0 0 T o t a l 61 266 136 191 63 I t should be noted that the observations were made i n three d i f f e r e n t seasons, l a t e w i n t e r (March), e a r l y s p r i n g (May), and summer (Ju l y - A u g u s t ) . No calves would be expected i n March and i n mid-May not a l l calves would have been born. From the a i r , unless one i s very c l o s e to the animals, i t i s very d i f f i c u l t to d i f f e r e n t i a t e between calves and y e a r l i n g s and so even the summer s i g h t i n g s cannot be considered as accurate counts. The March y e a r l i n g counts, however, leave no p o s s i b i l i t y of confusion w i t h calves and the y e a r l i n g s are small enough to be d i s t i n g u i s h e d from a d u l t s . Ellesmere I s l a n d The herd s i z e frequencies obtained by ground and a e r i a l observations i n summer and wi n t e r from herds on Fosheim Peninsula and a t Lake Hazen are given i n Table X X I I I . - 91 Table X X I I I Muskoxen Herd S i z e Frequency A e r i a l and Ground Observations. Ellesmere I s l a n d . N.W.T. Summer Observations Winter Observations Herd Fosheim Pen. Lake Hazen 1959; N. of Lake Fosheim Pen., 1951 S i z e Aug. 21 • . 1951 Aue. 10.1958 Hazen.1959, Ground A e r i a l Ground A e r i a l A e r i a l A e r i a l Ground Observations 1 2 10 6 1 5 10 0 2 3 - 4 1 1 3 1 3 2 2 1 4 1 1 5 1 2 1 1 3 6 2 1 1 1 2 7 1 1 2 1 8 3 1 2 1 1 9 1 1 2 3 10 2 1 1 11 l 1 1 12 1 1 14 1 1 2 15 1 1 1 16 1 17 1 18 1 21 1 29 1 Tota! Obser-i 13 22 19 13 12 20 11 vations - 92 -The percentage frequencies have not been c a l c u l a t e d because of the s m a l l t o t a l number of obse r v a t i o n s . The data do suggest, however, t h a t i n w i n t e r the frequency of s i n g l e animals i s lower than i n summer and t h a t the frequency d i s t r i b u t i o n of herd s i z e s , i n summer and w i n t e r data, i s f a i r l y uniform f o r herds of three animals or more. The average herd s i z e s , as c a l c u l a t e d from summer and wi n t e r (April-May) s i g h t i n g s on Fosheim P e n i n s u l a and at Lake Hazen, are giv e n i n Table XXI?, The mean herd s i z e i n August on Fosheim Pe n i n s u l a i s 8.2 and a t Lake Hazen 6. The l a r g e s t herd seen on the Peninsula i n summer contained 29 i n d i v i d u a l s . I n the l a t e w i n t e r p e r i o d of April-May the l a r g e s t herd there was composed of 18 muskoxen. Table XXIV Average Herd S i z e , A e r i a l and Ground Observations. Ellesmere I s l a n d . 1951. 1958 and 1959. Area Year Month S o l i t a r y No. of No. i n *Av. No./Herd B u l l s Herds Herds : Fosheim 1951 Apr.-May 0 11 116 11 Pen. June 0 11 87 8 Aug.4-6 2 13 84 6 Aug. 24 10 12 121 10 Lake Haz en 66 1958 June-July 6 13 5 Aug. 10 1 12 70 6 Lake Haz en 8 1959 Aug. 2 2 3 23 Aug. 4 5 3 23 8 N. of 60 Lake Hazel L1959 Aug. 2 3 6 10 1 Aue. 4 7 3 28 9 •Figures t o nearest whole animal. - 93 -Results of ground observations are given i n Table XXV below. Table XXV Muskox Herd Ground Observations. Ellesmere I s l a n d . 1951. 1954. 1958. Year 1951 1954 1958 Area Fosheim Penin. Fosheim Penin. Lake Hazen Observer J.S. Tener P. Bruggemann J.S. Tener No. of Herds 12 12 A d u l t B u l l s 21 21 A d u l t Cows 46 30 Immatures 8 14 Y e a r l i n g s 3 6 Y e a r l i n g 8.0 percent 3.4 Calves 9 0 5 C a l f percent 10.7 0 6.6 Cow-calf ra t i o l:.196 H.166 T o t a l 87 150 76 The 1951 data are based on 12 herds seen during the month of June; the end o f the normal c a l v i n g season i s b e l i e v e d to be the l a s t week i n May or the f i r s t week i n June. The 1954 data were obtained by Mr. Paul Bruggemann (1954), f o r m e r l y of Science Service, Department of A g r i c u l t u r e , who during the course of h i s summer i n v e s t i g a t i o n s on Fosheim Peninsula saw no calves i n the herds he observed. The 1958 data were gathered during the l a t t e r part of June and during J u l y , and represent about one h a l f of the t o t a l muskox p o p u l a t i o n b e l i e v e d t o e x i s t i n the v i c i n i t y of Lake Hazen. A e r i a l observations of the animals, conducted by three observ-e r s , are given i n Table XXVI. The c a l f percentages f o r the years 1948 and 1950 are based on t o t a l counts of animals, i n c l u d i n g s o l i -t a r y b u l l s , but f o r other years are confined to herd animals o n l y . The counts were obtained by Kelsall. (1948), Lawri.e (19 50) and me. Table XXVI Muskox A e r i a l Observations, Ellesmere I s l a n d  Year (August 1948 1950 1951 1958 1959 1959 Area Fosheim Fosheim Fosheim Lake Lake A l e r t : Pen. Pen. Pen. Hazen Hazen P l a t e a u Observer LP.Kelsal . A. Lawrie J.S. Tener J.S. Tener J.S.Tener J.S.Tener Wo.of Herds 11 7 .6 9 S o l i t a r y B u l l s 10 12 7 12 A d u l t s & immatures 43 381 112 52 38 56 Y e a r l i n g s 2 3 11 Y e a r l i n g 6.5 percent 14.1 Calves 9 32 9 5 5 11 C a l f percent 17.3 7.7 6.9 7.0 10.9 14.1 T o t a l 52 413 131 71 53 . 90 K e l s a l l w a s able to survey o n l y a small p a r t of the known muskox range on Fosheim P e n i n s u l a , but Lawrie had s u f f i c i e n t h e l i c o p t e r time to do a thorough survey. Tener covered the same c r i t i c a l areas as Lawrie but saw f a r fewer animals. The Lake Hazen survey was not a systematic coverage but p r i n c i p a l g r a z i n g grounds were viewed, both i n 1958 and 1959. Further l i m i t e d data on the composition of Lake Hazen herds was obtained from two herds which had been shot many years previous t o o u r . " v i s i t . The remains of a herd of 13 animals were found a t the east end of the l a k e , near a hunting camp e s t a b l i s h e d by Robert E. : Peary, about 1906-07. The group c o n s i s t e d of two a d u l t b u l l s , f i v e a d u l t cows, one immature b u l l , f o u r immature cows and one y e a r l i n g . The second herd, found on the top of the d i v i d e between the Adams and the Very R i v e r s , c o n s i s t e d of three a d u l t b u l l s , one a d u l t cow and two n e a r l y mature b u l l s . * 95 -C a l f Crops R e l i a b l e c a l f counts were obtained i n the Thelon Game Sanctuary d u r i n g the summers of 1951, 1952 and 1955 (Table X X I ) . The data f o r the l a t t e r year were obtained by two p a r t i e s working a t the same time i n d i f f e r e n t areas of the Sanctuary. Mr. John J . Teal had h i s base camp e s t a b l i s h e d near the j u n c t i o n of the Hanbury and Thelon R i v e r s , while the w r i t e r ' s camp was 100 miles f u r t h e r down the Thelon R i v e r , 20 miles above the F i n n i e R i v e r (Figure 3 ) . Because of t h i s d i s t a n c e f a c t o r , d u p l i c a t i o n of counts d i d not take p l a c e , and the data, t h e r e f o r e , can be grouped. The c a l c u l a t e d c a l f percentage was based on herd counts o n l y . S o l i t a r y b u l l s because of t h e i r wandering h a b i t s do not gi v e r e l i a b l e t o t a l count f i g u r e s and hence are not included i n the c a l -c u l a t i o n . I n one case a cow to c a l f r a t i o was obtained (1952) but i n most years the d i f f i c u l t y encountered i n d i f f e r e n t i a t i n g between cows and immatureanimals would not permit cow to c a l f c a l c u l a t i o n s w i t h any accuracy. The c a l f percentages f o r the three above years, 11.8, 13.1 and 10.5 are somewhat s i m i l a r when the 1955 f i g u r e s are lumped. While 'the i lower percentage of 7.3 I observed i n 1955 may r e f l e c t a s i g n i f i c a n t r e g i o n a l d i f f e r e n c e i n c a l f production f o r the year, a break down of the 1951 f i g u r e does not suggest t h a t the herds i n the j u n c t i o n area of the Sanctuary produce more calves r e g u l a r l y . The f i g u r e s i n 1951 i n d i c a t e about 9 per cent of 157 animals i n the j u n c t i o n area were calves w h i l e i n the lower or eastern p a r t of the sanctuary about 16.5 per cent of 97 muskox were c a l v e s . - 96 -A d d i t i o n a l i n f o r m a t i o n , though l e s s d e t a i l e d was obtained from a e r i a l counts i n the summer o f 1954 and 1957. Mr. J.P. K e l s a l l and Mr. J . J . Teal saw 266 muskoxen i n 1954 d u r i n g a e r i a l reconnaissances f o r calves i n the western p o r t i o n of the sanctuary. Of t h a t number 38, or 14.3 per cent, were c a l v e s . I n 1957 I counted 63 animals i n 9 herds, but there were no c a l v e s . On Ellesmere I s l a n d ground counts of muskoxen (Table XXV) are a v a i l a b l e from observations made on Fosheim Peninsula i n 1951 and 1954 and a t Lake Hazen i n 1958. I n 1951, 9 or 10.7 per cent of 87 muskoxen were c a l v e s ; i n 1954 there were no calves i n 150 animals; i n 1958, 5 or 6.6 per cent of 76 animals were c a l v e s . A e r i a l data from the same areas are given i n Table XXVI and i n a d d i t i o n two f l i g h t s were made over p l a t e a u country between Lake Hazen and / A l e r t i n 1959. The unusually high f i g u r e of 17.3 per cent f o r 1948 i s open to question, i n my o p i n i o n , i n t h a t the sample was small and the i n v e s t i g a t o r had l i t t l e previous e x p e r i -ence w i t h muskoxen and would tend to i n c l u d e y e a r l i n g s i n h i s c a l f counts. The f i g u r e s f o r the three years 1950, 1951, and 1958 are q u i t e s i m i l a r , ranging between 6.9 and 7.7 per cent. The 1959 count showed a higher c a l f crop at Lake Hazen and two f l i g h t s over the p l a t e a u country between Lake Hazen and A l e r t revealed an e x c e l l e n t production of 14.1 per cent. Y e a r l i n g Counts Y e a r l i n g ground counts from the Thelon Game Sanctuary are a v a i l a b l e f o r 1952, 1955 and 1956 (Table X X I ) . I n 1952 the per cent of y e a r l i n g s i n the herds observed was 8.3; i n 1955, 4.0, and i n 1956, 5.9. A e r i a l observations i n 1953, 1956 and 1957 (Table XXII) revealed y e a r l i n g percentages of 9*8, 6.3 and 6.3. The 1956 a e r i a l and ground f i g u r e s show c l o s e agreement. On Fosheim P e n i n s u l a , Ellesmere I s l a n d , 3»4 per cent of 87 muskoxen were y e a r l i n g s i n 1951, (Table XXV). At Lake Hazen, i n 1958, e i g h t per cent of 76 animals were y e a r l i n g s . The preceeding f i g u r e s are ground o b s e r v a t i o n s . The a e r i a l data f o r the Lake Hazen r e g i o n i n d i c a t e t h a t 2, or 2.8 per cent of 71 muskoxen seen i n 1958 were y e a r l i n g s (Table XXVI), w h i l e i n 1959 the percentage was 6.5» The ground counts of animals i n the Thelon and Lake Hazen areas do not provide i n f o r m a t i o n upon which c a l f s u r v i v a l can be . evaluated a c c u r a t e l y . F i r s t l y , the m o r t a l i t y r a t e of a d u l t s i s unknown and secondly the sampling e r r o r i n the counts i s so great t h a t any attempt to q u a n t i f y c a l f s u r v i v a l a c c u r a t e l y would be almost meaningless. With those r e s e r v a t i o n s i n mind, an examina-t i o n of the data suggests t e n t a t i v e l y a s u r v i v a l of calves i n the Thelon Game Sanctuary of b e t t e r than f i f t y per cent. For example, i n 1951 the herds counted there contained 11.8 per cent calves and i n 1952 contained 8.3 per cent y e a r l i n g s . I n 1955 calves c o n s t i -t u t e d 10.5 per cent and by A p r i l 1956, were 5.9 per cent of a l l muskoxen counted. A e r i a l counts provide corroborative i n f o r m a t i o n about the s u r v i v a l of calves born i n 1955, f o r i n March, 1956, an a e r i a l survey revealed 6.3 per cent of 191 muskoxen were y e a r l i n g s , a f i g u r e s i m i l a r . t o the iground counts. The Ellesmere I s l a n d data are of even l e s s value, f o r y e a r l i n g counts taken a year a f t e r c a l f counts were obtained on only two occa s i o n s . On Fosheim Peninsula the 1950 c a l f composition was 7.7 - 98 -per cent while the 1951 yearling composition was 3.4 per cent, suggesting a survival of calves of less than f i f t y per cent. However, at Lake Hazen calves constituted 6.6. per cent of herd animals i n 1958 and one year later yearlings totalled 6.5 per cent. Reproduction The period of greatest sexual activity of the bulls i n both the Thelon Game Sanctuary and at Lake Hazen appears to be during the second and third week of August. In the former area bulls were noticed to mount cows unsuccessfully on August 10 and 16, 1952. On August 15, 1955, a successful coitus was observed in the same area. At Lake Hazen no definitely successful matings had been observed up to the last observations of August 16, 1958. A bull i n a herd of nine animals attempted coitus with two cows several times on that date but except for one apparently successful mating, the cows would not allow completion. It i s l i k e l y that they had not yet come into heat f u l l y . The above observations suggest that the principal time of mating i n both high and low Arctic areas i s i n the third week of August, but that variations either side of that period probably occur (Tener, 1954). L i t t l e additional new information has been obtained about calving since the 1951 studies on Fosheim Peninsula (Tener, op. c i t . ) , where i t was found calving had commenced on April 22„ and •terminated the f i r s t week i n June. On April 22, 1956 a twenty-four hour old calf was observed i n a herd i n the north-east portion of 99 the Thelon Game Sanctuary. Examination of the area showed t h a t the cow had given b i r t h to her c a l f w h i l e w i t h the herd i n a s h e l t e r e d stream v a l l e y . An ad u l t cow c o l l e c t e d there A p r i l 5th c a r r i e d a f u l l y formed c a l f which weighed 20 pounds, some s i x pounds l e s s than the c a l f mentioned p r e v i o u s l y . I t i s probable t h a t the foetus would have reached term about the same time as the l i v i n g c a l f . At f i r s t glance the c a l v i n g p e r i o d may seem out of pla c e as wi n t e r c o n d i t i o n s p r e v a i l u n t i l e a r l y June. On r e f l e c t i o n , however, the t i m i n g pro-bably permits calves to o b t a i n the g r e a t e s t b e n e f i t from new vegeta-t i o n as most of t h e i r food i n t a k e f o r the f i r s t two t o f o u r weeks i s m i l k . Calves observed i n herds a t Lake Hazen i n the middle of June, 1958, were s e v e r a l weeks o l d and were g r a z i n g as s t e a d i l y as o l d e r animals. The only i n f e r e n c e to be drawn i s t h a t the calves were born sometime i n May. No data were obtained i n the f i e l d about the le n g t h of the g e s t a t i o n p e r i o d of.muskoxen. The i n d i r e c t evidence from the ob-se r v a t i o n s of mating and c a l v i n g i n the Thelon Game Sanctuary, would suggest a p e r i o d between eight and nine months, but more p r e c i s e i n f o r m a t i o n i s needed. The l e n g t h of the l a c t a t i o n p e r i o d of a cow which has given b i r t h to a c a l f i s not known. Calves commence feeding on vegeta-t i o n when two to three weeks of age (Tener, op. c i t . ) but continue to s u c k l e throughout the f i r s t year of t h e i r l i v e s a t l e a s t , and probably much longer. On A p r i l 9» 1956, f o r example, a y e a r l i n g was observed to suckl e a cow i n a herd i n the Thelon Game Sanctuary and on August 16, 1958 an animal approximately 15 months o l d suckled a cow a t Lake Hazen. 100 * The frequency of c a l v i n g by a d u l t cows w i l l have to be determined under experimental c o n d i t i o n s e i t h e r i n the f i e l d or a t a research s t a t i o n . As reported by Tener (1954) and other authors, cows w i t h y e a r l i n g s do not a l s o have c a l v e s , suggesting t h a t c a l v i n g does not occur every year i n the w i l d . P a r a s i t e s The p a r a s i t e f i n d i n g s during the post mortem examinations of the three a d u l t b u l l s c o l l e c t e d i n August 1957 i n the Thelon Game Sanctuary have been pu b l i s h e d (Gibbs and Tener, 1958). A copy of th a t paper i s i n c l u d e d i n Appendix I I . Three species of nematodes and three species of cestodes were i d e n t i f i e d . F i r s t records of the nematode Nematodirella l o n g i s p i c u l a t a (Romanovitch, 1915) and of the cestode Echinococcus granulosus (Patsch, 1786) were obtained from the h o s t s . Only one p a r a s i t e species was found from the two a d u l t cows c o l l e c t e d i n A p r i l , 1956. I t was C y s t i c e r c u s t e n u i c o l l i s . Rudolphi, 1880, t h e . l a r v a l form of Taenia hvdatigena. P a l l a s , 1776, and was on the surface of the l i v e r of one animal. P a r a s i t e s obtained from the three a d u l t b u l l s shot during the summer of 1958, a t Lake Hazen, Ellesmere I s l a n d , were confined to two s p e c i e s , Monezia expansa (Rudolphi, 1805) and C y s t i c e r c u s  t e n u i c o l l i s . Rudolphi,1880. The former was found i n the i n t e s t i n e s of two animals, one c o n t a i n i n g at l e a s t 11 long worms which were entwined i n a dense mass. Only two specimens of C y s t i c e r c u s were found, both i n one animal. One specimen was on the surface of the l i v e r and the other on the gre a t e r omentum. - 101 * No e x t e r n a l p a r a s i t e s have been found but predators, i n the terminology of A l l e e et a l (1949), i n c l u d e the black f l y (Similium sp.) and the mosquito (Culex s p . ) , w i t h only the l a t t e r being found i n the Queen E l i z a b e t h I s l a n d s . Swarms of these i n s e c t s can be found about the head and body of a muskox i n summer but the only places they appear to a l i g h t are around the eyes and nose of the h o s t . Examination of the eye l i d s of the f i v e b u l l muskoxen..collected d u r i n g the i n s e c t season showed numerous b i t e s . I n southern areas, such as the Thelon or other regions on the A r c t i c mainland where w i l l o w shrubs e x i s t , a c t i v e f e e d i n g by the muskox w i t h i t s head t h r u s t i n t o the shrubbery appears to reduce the nuisance value of the predators. I n high A r c t i c areas, however, where only pros-t r a t e v e g e t a t i o n e x i s t s , muskoxen have been observed to rub t h e i r eyes on t h e i r f o r e l e g s p e r i o d i c a l l y , o r to rub the closed o r b i t w i t h a hind hoof or o c c a s i o n a l l y w i t h a f o r e f o o t . Sometimes, when l y i n g down, the animals w i l l c l o s e t h e i r eyes f o r short periods or shake t h e i r heads i n e f f o r t s t o r i d themselves of t h e i r p e r s i s t e n t tormenters. At Lake Hazen no p a r t i c u l a r e f f o r t by muskoxen to face i n t o wind was observed, although i n the Thelon such a c t i o n has been recorded. B a c t e r i a l Diseases  Actinomycosis During the course of s k u l l v a r i a t i o n s t u d i e s , 196 s k u l l s i n museums and 266 s k u l l s found i n the f i e l d were examined f o r i n -d i c a t i o n s of e x o s t o s i s , such as might be caused by actinomycosis (Actinomyces b o v i s ) . I n a l l only six s k u l l s c a r r i e d a l v e o l a r l e s i o n s * 102 * of e x o s t o s i s . Four of these were a d u l t s b u l l s from the group of 236 s k u l l s examined at Lake Hazen, Ellesmere I s l a n d , one, an a d u l t cow 22 years o l d , which d i e d on Nunivak I s l a n d , A l a s k a , and one a d u l t b u l l from P r i n c e of Wales I s l a n d . The i n c i d e n c e of ex-o s t o s i s i n the Lake Hazen sample was 1.7 per cent. B r u c e l l o s i s The sample of whole blood sent to Dr. Connell was negative f o r b r u c e l l o s i s ( B r u c e l l a a b o r t u s ) . There has been no i n d i c a t i o n of b r u c e l l o s i s i n the muskox but i t was a t h e o r e t i c a l l y p o s s i b l e cause of the r a t h e r low production of calves observed i n most herds. I t i s r e a l i z e d one sample would not be i n d i c a t i v e of the degree of in c i d e n c e of b r u c e l l o s i s . A b n o r m a l i t i e s  S k u l l s The s e r i e s of Lake Hazen s k u l l s was g e n e r a l l y f r e e from ab-n o r m a l i t y . E i g ht b u l l s , however, had one horn broken, u s u a l l y at eye l e v e l , three had l o s t the t i p s of both horns, arid three i n -c l u d i n g a l i v e b u l l had l o s t one e n t i r e horn, horn core and boss. In the l a t t e r case, i t i s p o s s i b l e t h a t , f o r some reason, horn development never s t a r t e d on one s i d e . A very e a r l y i n j u r y to the area on the f r o n t a l bone where the bony core of the horn develops, may have occurred. The r i g h t horn of one a d u l t b u l l s k u l l had e v i d e n t l y been deformed i n youth, as the zygomatic arch was pressed inward by the encroaching horn. I n another a d u l t b u l l s k u l l , the nasal bones were pushed i n on the sides and the top. The appearance of the abnormality sug-gested an accident happened to t h e animal when i t was young. - 103 -Two o l d s k u l l s at Lake Hazen had damaged l e f t horns, t h e i r l e n g t h being reduced and the horns t w i s t e d . The horn was not broken but as growth had continued a f t e r i n j u r y to produce deform-i t y , i t i s l i k e l y t h a t the i n j u r i e s occurred during the second or t h i r d year of l i f e . No a b n o r m a l i t i e s were observed i n museum m a t e r i a l . Organic The o l d b u l l shot August 7, 1957, i n t h e Thelon Game Sanctuary, was c r y p t o r c h i d , the l e f t t e s t i s being completely contained w i t h i n the abdominal c a v i t y . I n many mammals the t e s t i c l e s normally remain i n the abdominal c a v i t y ; such animals, the t e s t i c o n d a , i n c l u d e the elephant, some i n s e c t i v o r a , hyrax, s l o t h s , a n t - e a t e r s , a r m a d i l l o s and cetacea. I n others the t e s t i c l e s descend p e r i o d i c a l l y during the p e r i o d of the r u t , and then r e t u r n i n t o the abdomen, or they may be extruded and r e t r a c t e d v o l u n t a r i l y ; t h i s i s t r u e of most rodents, many i n -s e c t i v o r a (moles, shrews, hedgehogs) and bats (Sisson and Grossman, 1950). Cryptorchism i s not r a r e i n horses, but probably i s not of frequent occurrence i n A r t i o d a c t y l a . No other organic abnormality has been observed. P h y s i o l o g i c a l Data  Blood A n a l y s i s The sodium and potassium values i n the blood of the three b u l l s c o l l e c t e d i n 1957 and analyzed at the U n i v e r s i t y of B r i t i s h Columbia are not yet a v a i l a b l e f o r i n c l u s i o n i n t h i s r e p o r t . - 104 -Fat A n a l y s i s Some of the r e s u l t s of the f a t a n a l y s i s have been published (Chisholra and Hopkins, 1957). That paper d e a l t w i t h the G17 f a t -t y a c i d p r e v i o u s l y known t o be present o n l y i n sheep. The authors estimated t h a t 1.7 per cent of the f a t t y a c i d s was heptadecanoic a c i d and 0.9 per cent 9-heptadecenoic a c i d . M i l k A n a l y s i s The r e s u l t s of the m i l k a n a l y s i s have been pu b l i s h e d by Tener (1956). A copy of the paper i s inc l u d e d i n Appendix I I . The gross composition v a l u e s , i n percentages, are gi v e n i n Table XXVII below: Table XXVII Gross Composition of Muskox M i l k i n Percentages. Constituent Average % of 2 samples Water 78.5 T o t a l s o l i d s 21.54 Fat . 11.0 S o l i d s not f a t 10.6 P r o t e i n s 5.3 N o n - A c i d - p r e c i p i t a b l e p r o t e i n s 1.8 A c i d - p r e c i p i t a b l e p r o t e i n s 3.5 Lactose 3«6 Ash 1.8 Vitamin B12 3.4 micrograms per l i t r e Rumen C i l i a t e s Dr. Lubinsky's f i n d i n g s i n h i s examinations f o r c i l i a t e s i n rumen j u i c e s from f i v e muskoxen are given i n Table XXVIII. Samples 1, 2 and 6 were incompletely preserved so do not provide f u l l i n -formation. - 105 -Table XXVIII PRELIMINARY LIST OF RUMEN CILIATES OF QVIBOS MOSCHATUS 1957 1958 Thelon Game Ellesmere ENTODINIINAE .Sanctuaryz I s l a n d 1 2 3 4 5 6 1 # * Entodinum anteronucleaturn D o g i e l , 1925 + + 2. * E. bicornutum D o g i e l , 1925 + + + 3. * E. damae Sladeoek, 194-6 + + + + 4. * E. dilobum D o g i e l , 1927 + + 5. * E. dubardi Buisson, 1923 + + 6. * E. exiguum D o g i e l , 1925 .' + + + + 7. * E. longinucleatum D o g i e l , 1925 + + + 8. E. nanellum D o g i e l , 1922 + + + 9. E. ovinum D o g i e l , 1927 + + DIPLODINIIAE 10. *Diplodinium d o g i e l i K o f o i d and MacLennan, 1930 + + + 11. Diplodinium sp. + + 12. *Eremoplastron impalae ( D o g i e l , 1925)... + + + + + 13. Eudiplodinium magii ( F i o r e n t i n i . 1889). + + + + + 14. *Metadinium magnum ( D o g i e l , 1925) + + + + + 15. Metadinium sp + 16. *Ostracodinium obtusum ( D o g i e l , 1925)... + + + + + 17. *Enoploplastron confluens ( D o g i e l , 1925) + + + + + 18. *E. t r i l o r i c a t u m ( D o g i e l , 1925) + + + + OBHRYOSCOLECINAE 19. Epidinium c a t t a n e i ( F i o r e n t i n i , 1889).. + + + 20. E. gigas ( D o g i e l , 1925) + 21. E. ecaudatum ( F i o r e n t i n i , 1889) + 22. E. caudaturn ( F i o r e n t i n i , 1889) ++ + + 23. E. bicaudatum ( F i o r e n t i n i , 1889).. + + + 24. E. tricaudatum ( F i o r e n t i n i , 1889) + + + ISOTRIGHIDAE 25. I s o t r i c h a ruminantium • + + + + * + * reported i n r e i n d e e r . Organ Weights and R e c t a l Temperature Data obtained about organ weights and r e c t a l temperature are provided i n Table XXIIX'. * 106 -Table XXIX Organ Weights i n Pounds and Rectal Temperatures. Adult Bull Muskoxen Specimen No, 1 2 3 . 4 5 6 Lake Lake Lake Place rhelon G.S. Thelon G.S. Thelon G.S. Hazen Hazen Hazen Date Aug. 5, Aug. 7, Aug. 11, June 2, July 18, Aug. 1957 1957 1957 1958 1958 1958 Liver Wt. 11.0 10.9 12.0 3.9 8.3 10.5 Heart Wt. 4.85 4.5 4.3 2.65 3.1 3.7 Lung Wt. 9.25 11.75 11.2 8.0 6.5 6.8 Spleen Wt. ; 1.7 1.6 1.3 .7 1.0 Kidney Wt. 1.75 1.9 1.95 1.2 1.6 1.8 Testis Wt. 1.2. 1.45 .9* Rectal Temp. 101.5° F 100.5°F 100.5°F 100.0°F * l e f t cryptorchid + prolonged death may have elevated temperature The Thelon specimens were obtained within four days of each other, but the three collected at Lake Hazen were shot over a two month period, resulting in rather interesting differences i n l i v e r weights with time. The June 2nd l i v e r specimen weighed 3.9 pounds, the July 18 specimen, 8.3 pounds, and the August 5 specimen 10.5 pounds. The rectal temperature of the bull shot August 5, 1957, i n the Thelon Game Sanctuary was 101.5° F., one degree higher than the other two specimens collected there. The August 5th specimen did not die immediately after being shot, but ran several hundred yards before death, possibly elevating i t s temperature. Discussion of physiological data Discussions of the milk analysis and of the pathological findings have been given i n the respective published papers which are i n Appendix II. The l i s t of rumen c i l i a t e s i n Table XXVHI,will 107 -be o f value i n f u t u r e metabolic s t u d i e s of muskoxen, p a r t i c u l a r l y i n probing the way the species makes use of the n u t r i e n t s a v a i l -a b l e to i t under A r c t i c w i n t e r c o n d i t i o n s . One would wonder f o r example, i f muskoxen might be able to synthesize p r o t e i n m a t e r i a l more e f f i c i e n t l y than domestic animals. A review of the l i t e r a t u r e by Oxford (1955), however, i n d i c a t e s t h a t much more work must be done on rumen c i l i a t e s of domestic l i v e s t o c k before a f u l l under-standing of the r o l e of c i l i a t e s i n ruminant d i g e s t i o n i s achieved. Most of the E n t o d i n i i n a e and D i p l o d i n i i n a e found i n muskoxen a l s o have been found i n r e i n d e e r by Lubinsky (1958a and 1958b). The weights of the organs obtained i n the current study are not very meaningful a t present, but w i l l serve as a b a s i s f o r f u t u r e s t u d i e s of the animals physiology. There i s a suggestion i n the data t h a t the Thelon specimens have l a r g e r organs than those from Lake Hazen but there are i n s u f f i c i e n t t o t a l weights of the animals to determine i f t h a t might be a f u n c t i o n of gross s i z e . The h e a r t - g i r t h measurements given i n Table XXXIX suggest t h a t t h i s may be so. Weights of organs of the horse, cow, sheep and muskoxa re given i n Table XXX, to serve as a b a s i s f o r comparison. I t i s i n t e r e s t i n g to note t h a t the l i v e r weights of the horse, cow and muskox are about the same, except f o r the muskoxen c o l l e c t e d i n l a t e w i n t e r and e a r l y summer a t Lake Hazen. The l a r g e r average body s i z e of the horse and cow would suggest t h a t muskox l i v e r s are l a r g e r p r o p o r t i o n a t e l y . 108 -Table X I X ins of tuskoxeh Weight i n Pounds of Organ of Selected Ungulates Mi • Thelon Game Organ Horse Cow Sheep - Sanctuary Lake Hazen K #2 #3 #4 #5 #6 Heart 9 5.5 4.85 4.5 4.3 2.65 3.1 3.7 Lung 7.5 9.25 11.75 11.2 8.0 6.5 6.8 L i v e r 10-12 10-12 1.25-1,5 11.0 10.9 12.0 3.9 6.5 10.5 Spleen 2.25-2.5 2 .25 1.7 1.6 1.3 .7 1.0 Kidney 1.25-(ave.) 1.5 1.5 .25 .875 .95 .975 .6 .8 .9 The i n c r e a s e i n l i v e r weights w i t h time i n the three Lake Hazen specimens, as pointed out on page 106 , may r e f l e c t i ncreased food storage w i t h the advent of summer v e g e t a t i o n . I t would suggest th a t the l i v e r may pla y an important r o l e i n the d i e t of muskoxen during w i n t e r months, perhaps by r e l e a s i n g gycogen and other nutrients d u r i n g times of environmental s t r e s s . The r e c t a l temperatures of the specimens c o l l e c t e d (Table XXIX) are comparable to those reported by Dukes (1955) f o r the beef cow (see Table XXXI . below) and to that reported by Cowan and Woods (1954) f o r b l a c k - t a i l e d deer. King's f i g u r e of 102°,quoted i n Back (1836), i s open to c o r r e c t i o n , both through p o s s i b l y f a u l t y c a l i b r a t i o n of the thermometer and the p o s s i b i l i t y t h a t the animal ran before death, thus e l e v a t i n g i t s temperature. The muskox temperature values would suggest t h a t t o l e r a n c e to the extremely low temperatures of the environment must be achieved p a r t l y through e f f e c t i v e i n s u l a t i o n of the pelage and not e n t i r e l y by a metabolic response. The c r i t i c a l temperature o f a muskox, i . e . , the temperature at which the metabolism of the animal must be i n -creased to o f f s e t heat l o s s , i s probably q u i t e low because of i t s - 109 -t h i c k h a i r c o vering. Another f a c t o r may be the u s u a l l y slow and methodical movement of the animals when f e e d i n g or otherwise l i v i n g an undisturbed l i f e . Heat l o s s e s and energy u t i l i z a t i o n under such c o n d i t i o n s would c e r t a i n l y be l e s s than i f t h e i r movements were h u r r i e d and quick. Table XXXI: R e c t a l Temperatures i n °F. Animal Average Range S t a l l i o n 99.7 99.0- 100.6 Mare 100.0 99.1 100.8 Muskox (Tener) 100.6 100.0 101.5 (King) 102.0 B l a c k - T a i l e d Deer 100.9 100.0 - 102.6 Beef cow 101.0 98.0 - 102.4 D a i r y cow 101.5 100.4 — 102.8 Sheep 102.3 100.9 — 103.8 Goat 103. a 101.7 - 105.3 P i g 102.5 101.6 103.6 Dog 102.0 100.2 - 103.8 Cat 101.5 100.5 - 102.5 Rabbit 103.1 101.5 - 104.2 M o r t a l i t y During the present i n v e s t i g a t i o n l i t t l e d i r e c t evidence o f the k i n d and s i g n i f i c a n c e of muskox m o r t a l i t y f a c t o r s was gathered by t h i s w r i t e r i n t h i r t e e n months of f i e l d i n v e s t i g a t i o n s i n s p r i n g , summer and w i n t e r . A s t r i k i n g f a c t , however, which became apparent during the study was the d i f f e r e n c e i n the number of dead muskoxen found on ranges i n the Thelon Game Sanctuary and on Ellesmere Is l a n d . In the former area only one b u l l and two cow skeletons were found i n the course of four d i f f e r e n t s t u d i e s there. On Fosheim P e n i n s u l a , however, 26 skeletons were observed i n 1951 i n one season's work (Tener 1954) and a t Lake Hazen 236 were found i n the course of a three months' study, of which 228 could be sexed. Table XXXII: - 110 -below gives the numbers of a d u l t s and immature s k u l l s found, e x c l u s i v e o f 19 known to be shot. Table XXXII.. Age Class and Sex of Muskox S k u l l s found near Lake Hazen. A d u l t Adult Immature Immature Immature Male Female Male Female Sex Unknown T o t a l Number 170 31 3 1 4 209 Per Cent 81.4 14.8 1.4 .5 1.9 100 One f a c t o r i n v o l v e d i n the great d i s p a r i t y i n the above numbers i s the d i f f e r e n c e i n the v e g e t a t i o n between the low and high A r c t i c . The denser p l a n t cover i n the Thelon area would tend to cover s k u l l s and s k e l e t o n s , p a r t i c u l a r l y i n the more t h i c k l y vegetated stream beds and along the main r i v e r banks. There are extensive tundra areas, however, both sid e s of the Thelon R i v e r which are used by muskoxen, p a r t i c u l a r l y i n w i n t e r , and remains of dead animals would be as v i s i b l e there as those i n high A r c t i c areas. There i s , however, another f a c t o r r e s p o n s i b l e f o r the d i f f e r -ence i n numbers of dead animals found. P o s s i b l e f e e d i n g areas f o r the estimated 350 muskoxen i n the Sanctuary i n v o l v e up to 15,000 square.miles ( l e s s the area of r i v e r s , l a k e s etc.) w h i l e the es-timated 200 muskoxen a t Lake Hazen moved over about 600 square miles or l e s s . The c o n c e n t r a t i o n of animals at Lake Hazen would permit the accumulation of carcasses i n a r e l a t i v e l y small area, and as the Sanctuary was not covered completely during the i n -v e s t i g a t i o n s , i t i s q u i t e p o s s i b l e t h a t most s k u l l s there were missed. .» 111 I t was i n t e r e s t i n g to note t h a t a t Lake Hazen, 94 of 141 a d u l t b u l l s k u l l s f o r which data were obtained, were i n wet areas, 69 of them being i n or along stream beds or shores of ponds. There were 14 of 24 cow s k u l l s i n the same environment. The remaining b u l l and cow s k u l l s were found i n dry s i t u a t i o n s , c h i e f l y c l a y h i l l s i d e s . The counts of l i v e animals (Table XXV) i n d i c a t e a .7:1 r a t i o i n the a d u l t p o p u l a t i o n and one might t h e r e f o r e have expected a somewhat s i m i l a r r a t i o i n the carcasses and s k u l l s . This d i s p a r i t y found i n the sex r a t i o s may be a t t r i b u t e d to a t l e a s t three p o s s i b l e causes. Adult b u l l s k u l l s are much h e a v i e r i n c o n s t r u c t i o n and would r e s i s t weathering, and chewing by other animals such as wolves and f o x e s , to a g r e a t e r degree than would cow or immature s k u l l s . Then, too, during t h e i r s o l i t a r y e x i s t -ence b u l l s are more subject to p r e d a t i o n than herd animals and one might expect t o f i n d more of t h e i r remains. This should have been r e f l e c t e d i n the sex r a t i o of l i v e animals, however. A t h i r d p o s s i b l e cause i s t h a t the s o l i t a r y b u l l s tended t o concentrate i n the b e t t e r f e e d i n g areas and were l e s s mobile than herds, r e s u l t i n g i n an accumulation of s k u l l s over the years. The p o s s i b i l i t y of Eskimo k i l l s i n the remains found cannot be overlooked. Such k i l l s can be detected under c e r t a i n circumstances. On two occasions a .'herd of animals had been shot by r i f l e f i r e , and c a r t r i d g e cases and s k u l l s o n l y were present, the l o n g bones and other bones of the muskoxen having been c a r r i e d away i n the meat. The animals i n the above two herds, t h e r e f o r e , have not been i n -cluded i n the m o r t a l i t y t a b l e . As f a r as could be determined, the - 112 -remaining animals i n the t a b l e d i e d from n a t u r a l causes. I f the technique of o b t a i n i n g the age of animals from tooth s e c t i o n s can be a p p l i e d to the muskox, i t should be p o s s i b l e t o co n s t r u c t a l i f e t a b l e f o r the Lake Hazen p o p u l a t i o n and perhaps determine the i n t r i n s i c r a t e of i n c r e a s e of t h a t group. P r e d a t i o n I n A r c t i c Canada one n a t u r a l predator of the muskox e x i s t s throughout i t s range, the A r c t i c wolf (Canis lupus subsp.). During the years the present study was underway, only two observations of s u c c e s s f u l wolf p r e d a t i o n were obtained. Mr. John J . Teal (pers. corresp.) reported seeing a wolf eat a c a l f muskox August 17, 1955, i n the Thelon Game Sanctuary. The next day two wolves appeared to be h a r r y i n g a herd of 4 a d u l t and two c a l f muskoxen i n the same area. During the same^ p e r i o d three wolves were observed to a t t a c k a lone b u l l , but the Jaitcome was not known. On A p r i l 22, 1956, a wolf was found on Thelon w i n t e r range s t a l k i n g a s o l i t a r y cow and her c a l f , both of whom had become separated from the main herd a few minutes before when the l a t t e r stampeded a f t e r g e t t i n g my scent. The day-old c a l f was unable to keep up and the cow had dropped behind to p r o t e c t i t . I t i s not known what the outcome would have been, had I not suddenly appeared, but i t i s s i g n i f i c a n t t h a t a wolf was nearby. No observations of wolves a t t a c k i n g muskoxen i n the Lake Hazen r e g i o n were obtained during the 1958 s t u d i e s , although a few wolves were s i g h t e d i n the area. One obs e r v a t i o n of an harassment was made by Mr. Paul Bruggemann, then of the Department of A g r i c u l t u r e , Ottawa, who saw s i x muskoxen being c i r c l e d by three wolves on - 113 -June 18, 1953, on Fosheim P e n i n s u l a . No k i l l s were made but on September 20, the remains of a r e c e n t l y k i l l e d immature b u l l were d i s c o v e r e d . Wolf populations i n the Sanctuary and a Lake Hazen were not h i g h . I n the l a t t e r area about t e n were b e l i e v e d to be present i n the summer of 1958. Numbers observed i n the Sanctuary during f i e l d i n v e s t i g a t i o n s ranged between one i n 1956 to 14 i n 1952. No evidence was obtained during the present study of the barren-ground g r i z z l y (Ursus a r c t o s r i c h a r d s o n i ) e i t h e r s t a l k i n g or k i l l i n g muskoxen. Diseases No evidence was obtained during the study t o i n d i c a t e t h a t any disease was k i l l i n g muskoxen. Accidents Only one p o s s i b l e case of i n j u r y s u f f e r e d i n an accident has been observed i n the current i n v e s t i g a t i o n . On August 9, 1952, a two year o l d muskox i n a herd of 38 on the north bank of the Thelon R i v e r near the F i n n i e R i v e r mouth was observed to have what appeared t o be broken r i g h t f o r e l e g . The animal h e l d the i n j u r e d limb o f f the ground and moved about on three l e g s . Behaviour  S o c i a l behaviour Muskoxen are s o c i a l animals b a s i c a l l y . They form herds, and although i n d i v i d u a l s composing herds may change from time to time, the herd i s the s o c i a l u n i t . A dult b u l l s are exceptions, f o r f r e -quently they ignore contact w i t h t h e i r f e l l o w beings and are s o l i -t a r y i n t h e i r h a b i t s . This observer has never seen, i n over 600 - 114 * muskoxen, an i n d i v i d u a l of any other sex or age c l a s s wandering alone, nor herds composed s o l e l y o f immature animals. As has been shown i n a previous s e c t i o n , the s i z e of a herd may vary c o n s i d e r a b l y , i n a l l seasons. The c e n t r a l f a c t , of course, i s t h a t herds are formed. I f has been p o s t u l a t e d by s e v e r a l pre-vious w r i t e r s t h a t the herd u n i t i s a form of defense, g i v i n g group p r o t e c t i o n when threatened or attacked by carnivorous predators, such as the w o l f . The t y p i c a l defensive motions of herd under wolf a t t a c k have been amply described (see Hone f o r summary), and suggest, as C l a r k e (1940) pointed but, t h a t a long a s s o c i a t i o n e x i s t s between the muskox and the w o l f . The p r o t e c t i o n a f f o r d e d c a l v e s , immature animals and cows by the defensive herd formation undoubtedly has s u r v i v a l value f o r the species as a whole but such tendencies on the part of the muskox can-not be a dominant behavioural t r a i t of them a l l f o r many b u l l s do not j o i n or form herds i n summer and are thus exposed to pred a t i o n to a f a r g r e a t e r degree. The d e s t r u c t i o n of such b u l l s by wolves would be o f l i t t l e consequence to re p r o d u c t i o n , however, as most herds c o n t a i n one o r more b u l l s , a l l of which are polygamous. Apart from defensive advantages, the herd may serve a more s u b t l e purpose by ensuring cows and b u l l s are together during the mating season, i n an otherwise comparatively r a r e and wide l y d i s t r i b u t e d s p e c i e s . A s o c i a l h i e r a r c h y e x i s t s w i t h i n those herds which have been observed i n t e n s i v e l y and o o n t i n o u s l y . A dominant animal e x i s t s which appears t o g i v e l e a d e r s h i p under c e r t a i n c o n d i t i o n s such as danger or f o r range movements. I n the Thelon Game Sanctuary, i t was ob-served i n A p r i l 9, 1956, t h a t a herd of 38 muskoxen which suddenly 115 « had become aware of the writer was led away for five miles by an old cow who started off at a fast walk and maintained i t , with occasional stops to allow the rest of the animals to catch up to her. The bulls i n the herd followed at the rear. Again at ^ake Hazen, a herd of 9 muskoxen was observed for six and one half hours on August 15, 1958, When f i n a l l y ..aware of the writer's presence, the herd moved off, lead by an adult cow which often was at least 100 yards ahead of the herd. The herd bull did not take the lead. On several occasions, during the rut, this writer has seen bulls become agressive i n the defense of a herd (or themselves) by placing themselves between the herd and the approaching writer. On a few occasions the bulls made short charges but usually returned by backing up to the herd. At times other than the rut, bulls are less aggressive and are more l i k e l y , i f i n a herd, to remain with the group rather than to sally forth. Even during the rut, however, offensive action i s not confined to bulls* On August 15, 1955, for example, a herd of 40 was under observation for five hours. When our presence became known to the muskoxen, an old cow and four bulls including the herd bull, moved toward us, the cow leading and intermittently running and walking. During the season of the rut, bulls exert leadership i n herds on many occasions and apart from their usual dominance over cows, may also influence the activities of younger animals. In the evening of August 9th, 1955, the writer watched a herd of 20 muskoxen work their way up the Thelon River, feeding as they went. Several of the immature animals were lagging behind u n t i l a large bull approached 116 -them, whereupon they r a n u n t i l mixed w i t h other animals** There are i n d i c a t i o n s t h a t o l d e r i n d i v i d u a l s exert a form of dominance over younger animals. On August 15, 1955, i n the Thelon Game Sanctuary, f o r example, an a d u l t cow i n a herd of r e s t i n g animals, walked over t o where an immature cow w$s l y i n g , stood a t her hind-quarters f o r a moment and then suddenly butted the younger cow who got up q u i c k l y and moved o f f to another spot. The e l d e r cow then l a y down i n the vacated area. On another occasion on J u l y 11, 1958, at Lake Hazen, a two year o l d male walked over to a year-l i n g f e e d i n g on w i l l o w and chased i t away. The y e a r l i n g picked another patch and the two year o l d again chased i t o f f . This time the aggressor ate some leaves and l a y down. The same animal was a l s o observed to dominate i n the same way a second two-year-old i n the herd. The f a m i l y r e l a t i o n s h i p i n muskoxen i s not c l e a r as y e t . Calves remain w i t h cows f o r probably two years i n a mother-offspring r e l a t i o n s h i p or u n t i l the next c a l f i s born. I n the second year of the c a l f ' s l i f e , the r e l a t i o n s h i p probably becomes more tenuous, although the y e a r l i n g s t i l l draws nourishment by s u c k l i n g the cow o c c a s i o n a l l y . By the end of i t s second year, a young muskox appears to be a p a r t of the herd s o c i a l s t r u c t u r e and no longer f o l l o w s i t s parent w h i l e g r a z i n g , or rushes to her when danger t h r e a t e n s . A l l observations made to date by t h i s w r i t e r suggest t h a t b u l l s show only the same concern f o r a c a l f ' s s e c u r i t y as f o r any other i n d i v i d u a l w i t h i n the same herd. - 117 -S o l i t a r y B u l l s There has been much d i s c u s s i o n i n the l i t e r a t u r e about the s o l i -t a r y h a b i t s of b u l l s and the general o p i n i o n i s that such animals are o utcasts from herds. Ages of s o l i t a r y b u l l s , as determined by f i e l d observations of t h i s w r i t e r , range from the newly matured i n -d i v i d u a l s of f i v e or s i x years to the very o l d . There are probably a t l e a s t two f a c t o r s i n v o l v e d i n such be-h a v i o u r . One i s r e p r o d u c t i v e and the other i s the temperament of o l d e r animals. During the mating season contests between b u l l s are h e l d f o r the possession of a herd. Such contests u s u a l l y occur i n the pre-sence of a herd, but o c c a s i o n a l l y take place d u r i n g the r u t t i n g season whenever two s o l i t a r y b u l l s meet. One b u l l , i n herds so f a r observed, appeared to be i n possession of a herd at the height of the r u t and v i g o u r o u s l y r e j e c t e d or attempted t o r e j e c t other b u l l s which t r i e d to j o i n the herd. The l o s e r s of such b a t t l e s move away and search f o r another herd or remain i n the general area f o r f u r t h e r attempts or u n t i l another herd appears. I t has been suggested (Jensen, 1904) t h a t b u l l s reaching matu-r i t y i n a herd are f o r c e d to leave by an o l d e r b u l l when the r u t -t i n g season commences. That has never been observed by t h i s w r i t e r , but on the other hand a l l of the young a d u l t b u l l s , which can be recognized by t h e i r l i g h t coloured horns, have been found to be e i t h e r by themselves or w i t h other o l d e r b u l l s at t h a t season. The p r e c i s e process i n v o l v e d i n the departure of young mature b u l l s from the herds has yet t o be d e f i n e d , but i t may centre around e j e c t i o n by an o l d e r , more experienced animal. I t i s a l s o p o s s i b l e - 118 -t h a t i t may r e f l e c t an increased i n t o l e r a n c e to others w i t h i n -creased hormone l e v e l s . P o s s i b l y because of such incr e a s e d i n t o l e r a n c e of b u l l s f o r other s , s o l i t a r y b u l l s wander f a r and wide, o f t e n many m i l e s from others of t h e i r k i n d . Pedersen (1931) has suggested t h a t c o l o n i z a -t i o n o f an area by the animals i s preceded by the appearance o f these s o l i t a r y i n d i v i d u a l s . Recent records i n d i c a t e t h a t t h i s may be so. The f i r s t s i g h t i n g i n 39 years of a muskox on Banks I s l a n d , an' a d u l t b u l l , was made i n 1952 by Mr. T.H. Manning (1953) a t the northern end of the i s l a n d . I n 1954 a herd of 30 was observed t h e r e . Muskoxen were b e l i e v e d to have been e x t i n c t on V i c t o r i a I s l a n d but three b u l l s appeared near Cambridge Bay during the summer of 1958, suggesting the reoccupation of the southern p a r t of the i s l a n d . Apart from the p o s s i b i l i t y of r e c o l o n i z i n g an area, the wide ranging i n d i v i d u a l s would ensure a mixing of the gen e t i c characters of the subspecies. I n my experience s o l i t a r y b u l l s are not confined to o l d animals, unable to breed but a l s o i n c l u d e the r e c e n t l y mature but inexperienced i n d i v i d u a l s which e v e n t u a l l y may be ab l e to prove stronger or more capable f i g h t e r s and so ga i n a herd. B u l l s which have l e f t herds on occasion group together to form s m a l l herds of t h e i r own during the non-breeding season. These herds, i n the Thelon Game Sanctuary and on Ellesmere I s l a n d , v a r i e d i n s i z e from two i n d i v i d u a l s to seven. There i s a tendency, as the data show i n Table XIX, f o r the herds o f b u l l s to form i n w i n t e r and to break up i n summer, although as many as s i x have been seen together as late as e a r l y August on Fosheim P e n i n s u l a . That p a r t i c u l a r herd was watched f o r s e v e r a l hours and i t was i n t e r e s t i n g t o see i t e v e n t u a l l y 119 -break up w i t h the animals going t h e i r s e v e r a l ways* A second p o s s i b l e reason f o r s o l i t a r y behaviour by o l d b u l l s i s the l o s s of re p r o d u c t i v e v i g o u r and a s s o c i a t e d d e s i r e t o ac-q u i r e a herd. Some o l d b u l l s , i n summer, appear content t o feed and r e s t . I n the Thelon Game Sanctuary, b u l l s have been seen to spend the r e p r o d u c t i v e p e r i o d i n i s o l a t i o n on i s l a n d s i n the Thelon R i v e r . Some show l i t t l e concern over the presence o f man or wolf and do not e x h i b i t the aggressiveness of s e x u a l l y a c t i v e younger b u l l s during the r u t . Whether or not an a n t i s o c i a l d i s p o s i t i o n accompanies the reduced v i g o u r of a b u l l which may no longer take p a r t i n the r u t i s open to question, but from the observations of o l d animals i t would appear t h a t t h e i r p r i n c i p a l d e s i r e i s t o eat and s l e e p . I n c o n t r a s t i s the b e l l i g e r e n c y of s o l i t a r y b u l l s which are s e x u a l l y potent and are searching f o r mates. Such animals can become q u i t e aggressive w i t h the appearance of a person. On J u l y 22, 1952, f o r example, the w r i t e r and h i s a s s i s t a n t were chased back to t h e i r canoe by a s o l i t a r y b u l l . There are other examples i n l i t e r a t u r e of t h i s aggressiveness and the reader i s r e f e r r e d t o Hone (1934) f o r a good summary. Prebreeding Behaviour The time of the mating season has been discussed i n the section on r e p r o d u c t i o n (see p. 98 ). Some aspects of prebreeding behaviour have been c l a r i f i e d , but much remains t o be i n v e s t i g a t e d . The approach of the breeding season becomes evident i n l a t e June o r e a r l y J u l y when one b u l l contests the presence of other bulls - 120 * which may be i n or near a herd o f muskoxen . Such f i g h t s are i n -frequent and r a r e l y l a s t l o n g , the i n t r u d i n g animal u s u a l l y , i n my experience, r e t i r i n g from the f i e l d a f t e r s e v e r a l c l a s h e s . In l a t e J u l y o r e a r l y August, however, c o n f l i c t s are more numerous and of longer d u r a t i o n . S o l i t a r y b u l l s show more i n t e r e s t i n herds and b u l l s i n possession of them are more aggressive i n r e p e l l i n g advances of those b u l l s . Examples of the seasonal d i f f e r e n c e i n f i g h t i n g i n t e n s i t y have been given by Tener (1954). F i g h t s between b u l l s , which have been recorded i n l a t e winter, (Jennov, 1933). and e a r l y s p r i n g (Tener, 1954), are not considered to be motivated i n the same way as contests i n the breeding season. As I have p o s t u l a t e d i n an e a r l i e r paper (1954), there may be some d e s i r e on the p a r t of on b u l l to dominate another, but such f i g h t -i n g may be p r i n c i p a l l y a response to c e r t a i n s t i m u l i i n a behaviour p a t t e r n e s s e n t i a l l y r e l a t e d t o the mating season. Once the s t i m u l i have i n i t i a t e d a response, the r e s u l t may be the p a r t i a l comple-t i o n of a f i g h t . Subsequent to the Eureka observations i n 1951 by t h i s w r i t e r (1954), s e v e r a l b r i e f f i g h t s o u t s i d e the mating season were noted i n the Thelon Game Sanctuary. On A p r i l 9, 1956, f o r example, a herd of 38 muskoxen became alarmed a t our presence and took f l i g h t , l e d by an o l d cow. As the herd moved o f f , two a d u l t b u l l s r an a t each other banging heads together s e v e r a l times. Again on J u l y 31. 1957, two b u l l s were observed a t c l o s e quarters as they f e d i n a w i l l o w t h i c k e t . One b u l l e v e n t u a l l y n o t i c e d the observers and u t t e r e d a t h r o a t y noise as i f a i r were f o r c e d from i t s lungs through the nose and t h r o a t without a c t i v a t i o n of the l a r y n x . The b u l l then stamped i t s f r o n t f e e t together w i t h a n o t i c e a b l e thump, shaking the - 121 -ground, and ran to i t s companion f e e d i n g p e a c e f u l l y some 100 yards away. When near the l a t t e r , the aroused b u l l suddenly i n c r e a s e d i t s pace and charged i t s companion who turned towards the aggressor and ran t o meet i t i n a head-on crash. Both then turned away and walked o f f together to another f e e d i n g area u p - r i v e r . The a c t i o n s described above suggest displacement a c t i v i t y i n a c o n f l i c t between a t t a c k and escape d r i v e s , Pedersen (1958) has commented on the e l i c i t a t i o n of the f i g h t i n g response i n b u l l s by s t i m u l i other than the immediate defence or r e t e n t i o n of a herd. F u l l e r ( i n press) has given the r e a c t i o n s of b i s o n (Bison b i s o n b i s o n X B. b, atha-bascae) when suddenly confronted w i t h a s i t u a t i o n which arouses simultaneously the a t t a c k and escape d r i v e s of the animals. B r i e f f i g h t s occur on such occasions before the b i s o n run away. The nature of muskox f i g h t s by b u l l s has been de s c r i b e d o f t e n i n the l i t e r a t u r e (see Hone f o r r e v i e w ) . One a c t i o n which has not been p r e v i o u s l y reported to my knowledge i s the head-swinging of a, b u l l which has charged another i n possession of a herd. The action was observed twice w h i l e the w r i t e r was a t Lake Hazen, Ellesmere I s l a n d , I n the evening of J u l y 1, 1958, a herd of eight muskoxen was observed g r a z i n g on the slope of a mountain, A s o l i t a r y b u l l , which had l i g h t - c o l o u r e d horns, approached the s i n g l e herd b u l l d i r e c t l y upon s i g h t i n g the s l o w l y moving herd. The defending b u l l was o l d ; the l e f t horn and the centre of the boss were m i s s i n g . The o l d animal stood i t s ground w h i l e the younger charged. A f t e r impact, the younger b u l l backed away, swinging i t s head from s i d e to s i d e . Three times the younger animal charged and each time as i t backed up, the head swinging a c t i o n was c a r r i e d out. On - 122 J u l y 26 another s o l i t a r y b u l l charged the same herd b u l l t w i c e , r e p e a t i n g the head swinging motion as before. F u l l e r (I960) r e f e r s to s i m i l a r head swinging of b u l l b i s o n d u r i n g a g o n i s t i c behaviour. While b u l l s are f i g h t i n g , the cows and immature animals u s u a l l y show l i t t l e i n t e r e s t i n the proceedings. I t was unusual, t h e r e f o r e , to note the behaviour of f o u r cows and two calves on J u l y 26, 1958, at Lake Hazen. There were two b u l l s i n the herd when i t was f i r s t observed and s h o r t l y a f t e r the younger of the two suddenly turned and charged the "herd" b u l l . The cows and calves s c a t t e r e d b r i e f l y and then formed a c i r c l e around the con-t e s t a n t s , t u r n i n g t o watch. A f t e r the second c l a s h the b u l l s resumed g r a z i n g as d i d the cows and c a l v e s . Mating Behaviour The behaviour of the b u l l s w i t h herds i n mid-August was such as to i n d i c a t e t h a t cows must have s t a r t e d to come i n heat. On August 15, 1955, f o r example, a herd of 40 muskoxen was observed browsing on w i l l o w s and r e s t i n g on the shores of the Thelon R i v e r . There were 7 a d u l t b u l l s i n the herd, but s i x of these were on the periphery and any attempt on t h e i r p a r t to mix w i t h the cows was opposed by the seventh, a l a r g e and r e s t l e s s animal. That b u l l p a i d p a r t i c u l a r a t t e n t i o n t o two of the 14 cows present. He mated b r i e f l y w i t h one cow. On August 16, 1958, a herd of nine muskoxen were under observa-t i o n f o r n e a r l y seven hours a t Lake Hazen. Only one a d u l t b u l l was wi t h the herd and the two a d u l t s cows were without calves but had y e a r l i n g s . When one cow got up a f t e r r e s t i n g f o r h a l f an hour, the b u l l immediately arose, went over to the cow and mounted her f o r twenty seconds. The b u l l made three more attempts s h o r t l y a f t e r - 123 -but on each occasion the cow walked forward a few paces. On another occasion, about 15 minutes l a t e r , the b u l l again approached the cow but stopped a short d i s t a n c e behind her. Both animals stood s t i l l f o r a moment and then the b u l l moved forward along her r i g h t f l a n k , standing w i t h h i s head beside her shoulders. They again remained motionless u n t i l the cow moved ahead. The per-formance was repeated, but the cow then l a y down. Two hours l a t e r the b u l l attempted to serve both cows, i n each approaching the females from the r e a r , standing beside e i t h e r t h e i r l e f t or r i g h t f l a n k before mounting. The cows c o n s i s t e n t l y evaded h i s attempts. The b u l l then went to the immature females i n the herd (two 2 year o l d and one 3 year o l d ) who a l s o walked away. A f t e r being alarmed by the w r i t e r , the herd moved away, an< a d u l t cow l e a d i n g a t a good pace. This seemed to annoy the b u l l , f o r he rumbled s e v e r a l times and set out a f t e r her at a f a s t walk. When he caught up w i t h her he attempted to serve her once q u i e t l y and once i n a rush but both times was unsuccessful as the cow walked away. Throughout the day the b u l l o c c a s i o n a l l y snorted and rumbled a deep, t h r o a t y sound. P r e c o c i a l r u t t i n g behaviour was observed twice, on each occa-s i o n i n the Thelon Game Sanctuary. On March 28, 1956, d u r i n g the course o f an hour's observation of a herd of 38 muskoxen, an imma-t u r e b u l l was observed on three occasions t o mount momentarily a second immature b u l l . On A p r i l 9, a two year o l d b u l l mounted another two year o l d , and an a d u l t b u l l went over to them, presuma-b l y to i n v e s t i g a t e . - 124 Other Behaviour Muskoxen u s u a l l y have a q u i e t d i s p o s i t i o n , and most f r e q u e n t l y when observed, present a p i c t u r e of e i t h e r p e a c e f u l l y g r a z i n g or browsing or of r e s t i n g and ruminating q u i e t l y . T h e i r movements appear purposeful and slow u n t i l aroused by danger or combat. Many authors have commented on muskox d i s p o s i t i o n , i n c l u d i n g Pedersen (1958) i n h i s r e p o r t of h i s many observations of the Greenland animals. When g e t t i n g up a f t e r r e s t i n g , a muskox does so by throwing the body weight forward on i t s knees, l i f t i n g up i t s hindquarters by standing on i t s hind l e g s and then standing up f u l l y by u s i n g i t s f r o n t l e g s . To l i e down the muskox f i r s t k neels, lowers i t s hindquarters and then tucks i t s f o r e l i m b s under i t s e l f . Frequently an animal w i l l k i c k the surface of the ground w i t h i t s f r o n t hoof before l y i n g down. O c c a s i o n a l l y when a muskox i s alarmed w h i l e r e s t i n g , i t w i l l t h r u s t both f o r e l e g s i n f r o n t of i t , r a i s i n g the a n t e r i o r p a r t of i t s body from the ground but l e a v i n g the h i n d -quarters down. I f f u r t h e r alarmed the animal i s able to throw i t s weight forward s u f f i c i e n t l y to r a i s e i t s hindlegs and so be able to run o f f . The animals have been observed a t times t o r a i s e t h e i r , f o r e q u a r t e r s i n t h i s manner, when not alarmed, and to remain i n t h a t incongruous p o s i t i o n f o r s e v e r a l minutes. When f l e e i n g from p o s s i b l e danger or when i n v o l v e d i n combat the muskox i s capable of unexpectedly f a s t movement. The l i t e r a t u r e contains many references on t h i s p o i n t and i t was v e r i f i e d many times by t h i s w r i t e r . I n s p i t e of s h o r t , heavy l i m b s , the animals are able to move very q u i c k l y across broken ground or up shale slopes or 125 h i l l s and are able to maintain t h e i r speed f o r s e v e r a l m i l e s . When a herd runs from danger the animals u s u a l l y form a t i g h t group w i t h shoulders touching. Calves and immature animals stay w i t h i n the group and are d i f f i c u l t to i d e n t i f y . I f a h i l l (or high ground) i s w i t h i n v i s i o n of an alarmed herd, the animals o f t e n run toward i t and do not stop u n t i l i t has been reached and climbed. I t has been f r e q u e n t l y observed, too, t h a t a t l e a s t one animal i n a herd a t r e s t on a h i l l s i d e w i l l take a commanding view of the surrounding t e r r a i n . A b ehavioural t r a i t which has not yet been explained s a t i s -f a c t o r i l y i s the d i g g i n g of shallow p i t s , which i n the experience of the present w r i t e r have been l i m i t e d to f r i a b l e , sandy or c l a y s o i l s i n the study areas on Ellesmere I s l a n d . I n most cases the p i t s have had exposed and broken r o o t s or branches of the A r c t i c w i l l o w ( S a l i x a r c t i c a P a l l . ) w i t h i n . I t i s p o s s i b l e t h a t the animals s a t i s f y c e r t a i n mineral requirements by e a t i n g s o i l i n the p i t s , or the p i t s may have a sign-post value i n t e r r i t o r i a l marking. Many w r i t e r s have commented on the nose-rubbing behaviour a d u l t b u l l and cow muskoxen perform when danger threa t e n s . The behaviour i s c h a r a c t e r i z e d by the animal s t r e t c h i n g out one f o r e -l e g and rubbing the s i d e of i t s head i n the v i c i n i t y of the ante-o r b i t a l gland. Pedersen (1956) b e l i e v e s t h a t the a c t i o n serves the purpose of l u b r i c a t i n g the h a i r about the eye so t h a t i t w i l l form a t u f t and be kept out of the l i n e of v i s i o n of the animal. He a l s o suggested t h a t i t might serve a r e p r o d u c t i v e purpose by p r o v i d i n g scent. B e l l (1934) e a r l i e r put forward the same concept. 126 * The above behaviour was noted many times d u r i n g the present study and on one occasion i t appeared to have a s c e n t - d e p o s i t i n g purpose. On August 5, 1955, a s o l i t a r y a d u l t b u l l was observed i n a g u l l y beside the Back R i v e r about 15 m i l e s above the J e r v o i s e R i v e r mouth. The b u l l was observed, a t c l o s e range, to rub v i g o r -o u s l y i t s f a c e and s i d e of head by the a n t e o r b i t a l gland, on w i l l o w r o o t s , w i l l o w bushes and the earth s i d e of the g u l l y . A f a i n t sweetish odour was present immediately a f t e r the b u l l ' s departure. I t i s a l s o p o s s i b l e , however, that u r i n e may have c a r r i e d the scent. Such behaviour may s i g n i f y t e r r i t o r i a l marking, which occurs i n other ungulates such as the Roosevelt e l k (Graf, 1956). D i s c u s s i o n o f R e s u l t s Range Vegetation Analyses Comparisons of the Thelon and Lake Hazen range analyses y i e l d some i n t e r e s t i n g r e s u l t s . The data i n Tables VI and V I I b r i n g out the higher p r o p o r t i o n of woody species i n the Thelon. Willow, pro-bably the most important summer food f o r muskoxen i n both areas, covered s u b s t a n t i a l l y l a r g e r p r oportions of the summer ranges i n the Thelon, the percentages f o r the two ranges there averaging 29 and 47.6 per cent, w h i l e the percentage f o r the Lake Hazen summer range averaged 12.7 per cent. The per cent of bare ground i n both, regions was somewhat s i m i l a r to the values f o r the two Thelon ranges, averaging 62 and 34 per cent, w h i l e the two Lake Hazen values were 66.4 and 68.7 per cent. Comparison of the r e s u l t s of the analyses of wi n t e r range data from the Thelon and Lake Hazen areas i n Tables V I I and X r e v e a l s as - 127 i n summer range comparisons, the greater number of shrubby, woody genera on Thelon ranges. Genera, which are food plants, such as Betula. Empetrum. Ledum and Vaccinium (two species) are absent i n the Lake Hazen region, where Salix and Dryas occur (Cassiope tetra-gona also i s present i n certain areas but i s not a muskox food). Some of the important winter range foods i n the Thelon.Game Sanetuary were found to be Betula glandulosa. Empetrum nigrum, Ledum decumbens. Vaccinium uliginosum and V. V i t i s - Idaea L. var minus. They covered 18.4 and 29.4 per cent of ranges I and II respectively and contributed 85.79 per cent of the dry weight pro-duction of food of winter range I and 100 per cent of winter range II production. The important winter foods at Lake Hazen, Salix arctica. Carex  stans. Poa glauca. Festuca brachyphvlla. Alopecurus alpinus and possibly Dryas i n t e g r i f o l i a on winter ranges I and II constituted 21.32 and 20.17 per cent respectively of the area covered. The only food production figures available are those for Salix and Carex  stans and so i t i s not possible to evaluate their importance i n the total production of food by a l l food species. Unproductive ground on the Thelon winter ranges I and II totaled 64.97 and 61.8 per cent respectively. At Lake Hazen such ground averaged 20.36 and 68.75 per cent on the two ranges studied. Both of the latter figures do not reflect the area of ground without chamaephytes and hemicryptophytes, for a tiny moss species was recorded over much of the area. If the percentage of moss cover i s added to the clay, the figures then become 71.76 and 78.42 per cent. Those figures are comparable to that found by Tener (1954) - 128 -on Fosheim P e n i n s u l a , some 200 miles to the southwest of Lake Hazen, to those by Cowan (1946) on w i n t e r ranges ofumbuntain sheep and elk i n Jasper N a t i o n a l Park and by Webb (1957) on deer, sheep and e l k ranges i n Banff N a t i o n a l Park, Dry weight production of s e l e c t e d food species per acre a l s o was much higher i n the Thelon r e g i o n , although d i r e c t p l a n t species comparisons are d i f f i c u l t because of d i f f e r e n c e s i n genera and species of p l a n t s i n the h i g h and low A r c t i c , A comparison of w i l l o w food speci e s , S a l i x a l a x e n s i s and S^ a r c t i c a . however, r e v e a l s that the annual production o f the former was over s i x times as great as the l a t t e r and t h a t the t o t a l annual production of a l l food species i s about seven times as l a r g e per acre i n the Thelon, Comparison of food production on the w i n t e r ranges gives similar r e s u l t s . From s i x to t e n times as mueh i s produced on the Thelon ranges s t u d i e d as at Lake Hazen, A d u l t beef c a t t l e r e q u i r e about 3 l b s , of dry food matter per 100 l b s . of animal per day f o r maintenance ( G u i l b e r t and Rockford, 1940), While p r e c i s e muskox maintenance requirements are unknown, assuming the q u a l i t y of food i s equal a s i x hundred to eight hundred pound muskox, by e x t r a p o l a t i o n , would r e q u i r e between 18 and 24 l b s , , or between 8,17 and 10.89 Kilograms, of dry, good-quality forage per day. Based on food production alone one acre of the Thelon summer range stu d i e d would support on the above b a s i s , 1.6 a d u l t 800 lb,., muskoxen per month. This i s a minimum, h i g h l y t h e o r e t i c a l f i g u r e , f o r i t assumes complete consumption of a v a i l a b l e annual forages pro-duced, i g n o r i n g such f a c t s as wandering h a b i t s of the s p e c i e s , i t s maintenance requirements, and any t e r r i t o r i a l needs i t might have. - 129 The two w i n t e r ranges examined i n the Sanetuary would support i n a s i m i l a r way 1.2 and 1.9 muskoxen per acre per month. One acre of summer range and of winter range at Lake Hazen would support on the same b a s i s .232 and .186 muskoxen per month r e s p e c t i v e l y . I n other words an' a d u l t 800 l b . muskox a t Lake Hazen would need a t l e a s t f o u r acres of summer range t o o b t a i n s u f f i c i e n t food f o r one month and a t l e a s t f i v e acres of w i n t e r range. As pointed out above, other f a c t o r s w i l l g r e a t l y enlarge the area a c t u a l l y used by the animals, not the l e a s t of which i s the g r a z i n g i n t e n s i t y of the animals, an as yet unmeasured f a c t o r . I n summary, the data, though scanty, suggest that summer ranges i n the Thelon Game Sanctuary may support up t o about seven times as many muskoxen as summer ranges a t Lake Hazen and up to ten times as many muskoxen on the w i n t e r ranges. The a c t u a l number of muskoxen ranges i n e i t h e r area w i l l support, must be the subject of f u r t h e r study to define i n f l u e n c e s such as f e e d i n g i n t e n s i t y , d a i l y movements, t e r r i t o r i a l requirements and i n t e r s p e c i f i c compe-t i t i o n . Chemical analyses of muskox food p l a n t s and t h e i r r e l a t i o n , to muskox n u t r i t i o n D i e t a r y requirements of muskoxen l i v i n g i n the w i l d are un-known. Pending l a b o r a t o r y s t u d i e s of the animals, p r e f e r a b l y a t A r c t i c research s t a t i o n s , n u t r i t i o n a l requirements must be i n -f e r r e d from those known f o r domestic l i v e s t o c k and f o r w i l d c e r v i d s . A short d i s c u s s i o n f o l l o w s of ruminant n u t r i t i o n and of some of the n u t r i t i v e requirements of c e r t a i n ungulates. - 130 -Herbivores and c a r n i v o r e s r e c e i v e energy from the foods they consume. The gross energies of carbohydrates (4.15 Kcal/gm,) f a t s (9,40 K c a l per gram) and p r o t e i n (5,65 Kcal/gm) have been d e t e r -mined and provide a b a s i s f o r computing the gross energy values of food from t h e i r chemical compositions. However, not a l l of the gross energy as determined i n the bomb c a l o r i m e t e r i s u s e f u l to the body, as l o s s e s occur before the energy of the foods i s ac-t u a l l y u t i l i z e d . I n ruminants, such as the muskox, combustible gases, p r i m a r i l y methane, which are produced i n the breakdown of carbohydrates by microorganisms, are passed out and t h e i r energy i s l o s t t o the animal, A f u r t h e r p o r t i o n of the gross energy es-capes unused because, i n the case of p r o t e i n , the complete o x i d a -t i o n which gives r i s e to t h i s energy value does not take p l a c e i n the body. Whereas the end products of p r o t e i n o x i d a t i o n i n the c a l o r i m e t e r are carbon d i o x i d e , water and n i t r o g e n , catabolism i n the body r e s u l t s i n urea and other in c o m p l e t e l y o x i d i z e d n i t r o g e -nous end products which are excreted i n the u r i n e . Energy l o s s e s a l s o occur i n heat e l i m i n a t i o n i n d i g e s t i o n , but by f a r the l a r g e s t p a r t of the l o s s e s i s t h a t which occurs i n the faeces as a r e s u l t of Incomplete d i g e s t i o n . By determining the heat of combustion of the faeces and sub-t r a c t i n g t h i s value from the gross energy of the feed one obtains the d i g e s t i b l e energy. I f the sum of a l l energy l o s s e s i s sub-t r a c t e d from the gross energy values, a metabolizable energy value i s obtained - a value which r e f l e c t s the p o r t i o n of the t o t a l energy which i s a c t u a l l y capable of t r a n s f o r m a t i o n w i t h i n the body. - 131 -Maynard and L o o s l i (op. c i t . ) p o i n t out t h a t heat l o s s i s r e g u l a t e d by two components, p h y s i c a l r e g u l a t i o n by adjustment of the f l o w of blood to the s k i n and by p e r s p i r a t i o n , and by chemical r e g u l a t i o n or the i n c r e a s e i n metabolism. The nature o f the f o o d s t u f f s i n f l u e n c e s heat l o s s e s , apart from other i n f l u e n -c i n g f a c t o r s such as f a t and h a i r i n s u l a t i o n . The percentage of t o t a l p r o t e i n i n the r a t i o n , f o r example, has a d e f i n i t e e f f e c t on heat l o s s e s . As the p r o t e i n l e v e l i n e q u i c a l o r i c d i e t s i s i n c r e a s e d there i s a p r o g r e s s i v e decrease i n heat e l i m i n a t i o n thus i n c r e a s i n g the net energy v a l u e . Also the s u b s t i t u t i o n of f a t f o r carbohydrate i n a d i e t can r e s u l t i n a more economical use of energy from food because o f the l e s s e r amount d i s s i p a t e d i n heat. D e f i c i e n c i e s of phosphorus, r i b o f l a v i n and c e r t a i n other minerals and vitamines tend t o decrease the heat increment of a r a t i o n . I n summary there i s evidence t h a t - other f a c t o r s being equal - i f the r a t i o n i s unbalanced w i t h respect to any n u t r i e n t i n terms of p h y s i o l o g i c a l need, the wastage of heat tends to be g r e a t e r accordingly.' The a b i l i t y of a given source of p r o t e i n t o supply amino acids i n the r e l a t i v e amounts needed to form the nitrogenous t i s s u e s and compounds r e q u i r e d f o r body f u n c t i o n s i s r e f e r r e d to as i t s b i o l o -g i c a l value (Maynard and L o o s l i , op. c i t . ) . Those authors go on to say t h a t w h i l e i t i s reasonable to b e l i e v e t h a t the e f f i c i e n c y of u t i l i z a t i o n of absorbed amino a c i d s f o r maintenance purposes i n c a t t l e and sheep depends upon t h e i r q u a l i t a t i v e and q u a n t i t a t i v e d i s t r i b u t i o n i n the p r o t e i n mixture, as i s the case f o r non-ruminants, - 132 -the b i o l o g i c a l value of the mixture as consumed by the animal i s of minor importance, because r a t i o n s of poor p r o t e i n q u a l i t y are improved through the a c t i o n s of microorganisms i n the rumen. E s s e n t i a l amino a c i d s which are d e f i c i e n t i n the feed are suppl i e d by b a c t e r i a l s ynthesis but only from e x i s t i n g nitrogenous m a t e r i a l s . The absorbed acids are a mixture of those coming from the feed and from microorganisms, and there i s evidence that t h i s mixture does not vary markedly i n b i o l o g i c a l value no matter what combinations of feeds are used i n r a t i o n s . With the above d i s c u s s i o n i n mind, i t i s now p o s s i b l e to ex-amine d i e t a r y needs of domestic l i v e s t o c k and to attempt to e x t r a -p olate therefrom the needs of muskoxen. Nu t r i e n t allowances f o r beef c a t t l e have been worked out by the Committee on Animal N u t r i t i o n of the N a t i o n a l Research C o u n c i l of the United States (1950). Table XXXIII below gives the summa-r i z e d i n f o r m a t i o n of that committee. An e i g h t hundred pound b u l l muskox would r e q u i r e , on the above b a s i s , about 17 l b s . of a i r dry feed per day which should contain seven per cent d i g e s t i b l e p r o t e i n . Because a l l the p r o t e i n i n food i s not digested by an h e r b i v o r e , the t o t a l p r o t e i n content of such food must be somewhat higher. G u i l b e r t and Rockford (1940), f o r example, s t a t e that good q u a l i t y roughage f o r maintenance of a d u l t s should contain at l e a s t seven to eight per cent p r o t e i n , but that growing animals should have 10 to 12 per cent t o t a l pro-t e i n i n t h e i r r a t i o n . Espe and Smith (1952), however, suggest that f o r maintenance of l i f e , domestic stock r e q u i r e four per cent pro-t e i n . Those authors a l s o suggest that a four to f i v e per cent f a t content i n the d i e t i s a d e s i r a b l e optimum. - 133 -Table ZXXJLII D a i l y N u t r i e n t Allowances f o r Beef C a t t l e Body T o t a l A i r Digest T o t a l D i g e s t i b l e Calcium Phosph. Carotene Wt dry feed P r o t e i n N u t r i e n t fo % % mg./lb. ( l b . ) ( l b . ) fo Normal growth s t e e r s and h e i f e r s 400 12 7.5 58 0.37 0.28 2.0 600 16 5.6 53 0.25 0.21 2.2 800 19 4.7 50 0.16 0.17 2.5 B u l l s growth and maintenance (mod. a c t i v i t y ) 600 16 8.1 63 0.33 0.25 2.2 800 17 8.2 65 0.30 0.23 2.8 1000 20 7.0 60 0.24 0.20 3.0 Wintering weanling calves 400 11 6.4 55 0.32 0.24 2.2 500 13 6.2 54 0.27 0.20 2.3 600 15 5.3 53 0.24 0.18 2.4 Wintering mature pregnant cows 800 22 4.5 50 0.20 0.18 2.2 900 20 4.5 50 0.20 0.18 2.7 Cows n u r s i n g c a l v e s . 1 s t 3-4mo. a f t e r p a r t u r i t i o n 900-1000 28 * 5.0 50 0.24 0.18 11.0 According t o the above t a b l e , an 800 l b . b u l l would r e q u i r e 0.30 per cent calcium and 0.23 per cent phosphorous i n i t s d i e t . Watkins (1937) s t a t e s t h a t below normal r e s u l t s w i l l ensue i f the calcium content of range forage i s l e s s than 0.25 per cent and i f the phosphorous value i s l e s s than 0.12 per cent. Adequate calcium and phosphorous n u t r i t i o n , however, i s dependent on three f a c t o r s : a s u f f i c i e n t supply of each element, a s u i t a b l e r a t i o between them (2:1 to 1:2) and the presence of v i t a m i n D, the l a t t e r promoting calcium and phosphorous a b s o r p t i o n . 134 Vitamins A, and D must be obtained from food consumed, but f o r ruminants, once the rumen begins to f u n c t i o n , there i s no dietary-need f o r the B v i t a m i n s , as they are then s y t h e s i z e d i n adequate amounts (e.g. Dukes, 1955). Vitamin A.- i s found i n f r e s h , l e a f y forage and plays a v i t a l r o l e i n r e p r o d u c t i o n . The v i t a m i n can be sto r e d i n the l i v e r , where i t provides newborn w i t h colostrum and mi l k which are r i c h e r i n the v i t a m i n t h a t they would be otherwise. U n t i l such times when the young are able to o b t a i n v i t a m i n A from forage, m i l k vitamins p l a y an e s s e n t i a l r o l e i n the growth and sur-v i v a l of young. This may be an important f a c t i n s u r v i v a l of muskox calves which are born i n a winter environment and which do not eat green food u n t i l they are one to two months of age. Muskoxen would have t o s a t i s f y t h e i r v i t a m i n A requirements during the s p r i n g and summer months - mid-June to e a r l y August, when forage i s green. By l a t e August v e g e t a t i o n u s u a l l y has matured and i s undergoing the us u a l chemical changes a s s o c i a t e d w i t h autumn. The l i v i n g t i s s u e s of pasture grass and other forages are p r a c t i c a l l y devoid of v i t a m i n D. During the sun c u r i n g o f p l a n t s , however, which occurs n a t u r a l l y i n . A r c t i c regions where f a s t matu-r a t i o n , 24 hour s u n l i g h t , low p r e c i p i t a t i o n and e a r l y f r o s t s pre-v a i l , v i t a m i n D i s formed under the a c t i o n of r a d i a n t energy upon e r g o s t e r o l or some other provitamin (Maynard and L o o s l i , op. c i t . ) , and such p l a n t s then would provide some of the v i t a m i n . S u n l i g h t i s l e s s e f f e c t i v e l y obtained through heavy coats of h a i r . F r a n k l i n (1953) has suggested t h a t when the sun i s below the 25° azimuth i n A u s t r a l i a , the heavy wool cover on sheep produced a v i t a m i n D d e f i c i e n c y . Not only do muskoxen have an e x c e p t i o n a l l y - 135 heavy coat o f i n n e r and outer h a i r , but the animals on the higher A r c t i c i s l a n d s r e c e i v e no s u n l i g h t f o r as long as f o u r months o f the year and f o r an a d d i t i o n a l p e r i o d of a t l e a s t a month r e c e i v e low i n t e n s i t y amounts. I t i s probable t h a t muskoxen, and other A r c t i c h e r b i v o r e s , r e c e i v e t h e i r v i t a m i n D through exposure to 24 s u n l i g h t i n summer and v e g e t a t i o n i n w i n t e r . I t would be i n t e r e s t -i n g t o see i f muskoxen s t o r e v i t a m i n D i n some way to counteract the long dark p e r i o d s . I n a d d i t i o n t o increased requirements f o r n u t r i e n t s during growth of immature animals, g e s t a t i o n and l a c t a t i o n by females c r e a t e g r e a t e r demands f o r c e r t a i n elements o f the d i e t . I n early pregnancy, f o r example, q u a n t i t a t i v e demands f o r n u t r i t i v e material are s m a l l but they p r o g r e s s i v e l y i n c r e a s e t o become s e v e r a l times as l a r g e towards term. The U.S. Department of A g r i c u l t u r e (1939) s t a t e s t h a t the p r o t e i n requirement may r i s e 40 per cent above that of maintenance during the l a s t three months of pregnancy of cows and t h a t the average through pregnancy i s about 17 per cent higher. Not o n l y i s i t important f o r the pregnant animal to have a d d i t i o n a l p r o t e i n , minerals and vitamins f o r f o e t a l growth, but she must be a b l e t o s t o r e reserves f o r the p e r i o d immediately f o l l o w i n g p a r t u -r i t i o n when the food supply may be incapable of meeting demands f o r l a c t a t i o n . I f t h a t should happen the cow then has to draw on her r e s e r v e s . I n the d i s c u s s i o n on l a c t a t i o n (Tener, 1956), the r e l a t i v e l y h i g h f a t content of muskox mi l k was p o s t u l a t e d to be a means of a s s i s t i n g the calves to cope w i t h a r i g o r o u s environment. I n t h i s connection i t i s i n t e r e s t i n g to note t h a t Maynard and L o o s l i (op.cit.) - 136 -have pointed out th a t environmental temperature i s the primary cause of v a r i a t i o n i n f a t values i n m i l k of domestic cows which has i t s highest value i n winter and lowest i n summer. Pregnant muskoxen have t h e i r g r e a t e s t n u t r i t i v e requirements i n the l a t t e r p a r t of the w i n t e r when temperatures are w e l l below zero and when n u t r i t i v e values of food species would be lower than i n summer. The analyses of p l a n t s of temperate c l i m a t e s show that w i t h advancing age crude p r o t e i n and phosphorous decrease i n value and crude f i b r e , l i g n i n , c e l l u l o s e and other carbohydrates i n c r e a s e (Stoddard and Smith, 1955; Einarsen 1946: among o t h e r s ) . Seasonal changes are a f f e c t e d by both changes i n the stem-leaf r a t i o and a c t u a l changes i n composition w i t h i n each p l a n t . Browse p l a n t s g e n e r a l l y show l e s s seasonal f l u c t u a t i o n s than grasses. Being deep rooted g e n e r a l l y and tending to store i n the stems r a t h e r than i n the r o o t s , they do not decrease i n p r o t e i n , v i t a m i n A and car-bohydrates d u r i n g w i n t e r as much as do grasses. Forbs do not cure w e l l , being i n f e r i o r as forage during the non-growing season (Stoddard and Smith, op. c i t . ) . G e l t i n g (1937), among other s , has suggested t h a t the r a p i d c u r i n g of v e g e t a t i o n i n A r c t i c regions and the e a r l y and consistent f r o s t s would tend to preserve n u t r i e n t s i n grasses and other p l a n t s . An a d d i t i o n a l f a c t o r i s the r e l a t i v e l y low p r e c i p i t a t i o n of the short autumn, which would reduce the l e a c h i n g a c t i o n more common i n southern v e g e t a t i o n i n autumn and e a r l y w i n t e r . Systematic c o l -l e c t i o n s of Ar c t i c p l a n t s are needed t o determine what changes i n n u t r i e n t s occur w i t h changes i n season. - 137 The p l a n t s c o l l e c t e d i n A p r i l , 1956, were the only specimens obtained i n w i n t e r during the present study. P l a n t s from other w i n t e r ranges i n the Thelon Game Sanctuary and a t Lake Hazen were c o l l e c t e d a t or near the end of the growing season and so do not r e f l e c t the n u t r i t i v e value they would have f o r the animals i n mid- o r l a t e w i n t e r . The 1956 samples, however, y i e l d q u i t e use-f u l i n f o r m a t i o n , f o r they g i v e some i n d i c a t i o n of the n u t r i t i v e q u a l i t y of the important foods i n l a t e w i n t e r a f t e r most of the degenerating changes have taken p l a c e . The samples suggest t h a t the browse species - l a b r a d o r t e a , b i r c h and the vacciniurns -o f f e r the highest p r o t e i n content and t h a t crowberry and la b r a d o r t e a provide the h i g h e s t f a t v a l u e s . The p r o p o r t i o n s of the v a r i o u s food p l a n t s i n the d i e t o f muskoxen are not known and i t f o l l o w s t h a t the metabolizable energy a v a i l a b l e t o the animals a l s o i s unknown, w i t h a l l t h a t the l a t t e r f a c t i m p l i e s , i . e . d i g e s t i o n c o e f f i c i e n t s , energy l o s s e s i n u r i n e , faeces and r e s p i r a t i o n and heat d i s s i p a t i o n . Smith (1959) has pointed out the dangers i n e v a l u a t i n g range p l a n t s , i n terms of food f o r ungulates, on the bases of chemical analyses alone. A l l tha t can be s a i d a t present i s t h a t on c e r t a i n ranges the animals consume unknown q u a n t i t i e s of known p l a n t s whose chemical composi-t i o n f o r a p a r t i c u l a r year are known. The data a v a i l a b l e do i n d i -cate a parameter about which f u t u r e s t u d i e s can be formed and do permit t e n t a t i v e conclusions to be drawn about the n u t r i t i o n a l value of the d i e t of muskoxen i n the Thelon Game Sanctuary and a t Lake Hazen. - 138 -The summer food of muskoxen, p a r t i c u l a r l y w i l l o w s , i n the Sanctuary would appear t o provide more than adequate amounts o f p r o t e i n , carbohydrates ( n i t r o g e n - f r e e e x t r a c t ) , calcium and phos-phorous, w i t h perhaps l e s s f a t than d e s i r a b l e . Winter range p l a n t s there probably provide s u f f i c i e n t p r o t e i n , f a t , carbohydrate and calcium f o r maintenance of l i f e . Phosphorous values are below those recommended by the American N a t i o n a l Research C o u n c i l (Table XXXIV) and by Watkins (1937) and those low values together w i t h the barely adequate p r o t e i n i n t a k e may have some i n f l u e n c e on the r e p r o d u c t i v e performance of females. I n view of the f i n d i n g s of Hart and GuUbert (1928) and others of the adverse e f f e c t s of phosphorous d e f i c i e n -c i e s a s s o c i a t e d w i t h a low p r o t e i n i n t a k e upon re p r o d u c t i o n i n range e a t t l e , such d e f i c i e n c i e s i n the d i e t of Thelon animals should be the subject of f u r t h e r study to determine i f the r e l a t i v e l y low muskox p r o d u c t i v e l y there has a d i e t a r y b a s i s i n p a r t . The Lake Hazen summer range foods examined have lower values of p r o t e i n and f a t (except f o r Melandrium t r i f l o r u m (R. Br.) J. Vahl than t h e i r Thelon counterparts, but probably are adequate f o r musk-oxen requirements. Calcium i n t a k e would be s u f f i c i e n t , f o r only Poa glauca M. Vahl has a calcium content l e s s than the recommended minimum. The l a r g e q u a n t i t i e s of w i l l o w muskoxen are known to con-sume probably would provide an adequate amount of phosphorous i n t h e i r d i e t . I t i s more d i f f i c u l t to i n t e r p r e t Lake Hazen winter range food values because of the unknown degree to which the obtained values are subject to chemical change as the season progressed from the time the p l a n t s were c o l l e c t e d t o w i n t e r . On the assumption t h a t - 139 willow, a browse species, does not loose much of i t s n u t r i t i v e value with time, i t would appear that the plant offers s u f f i c i e n t protein, f a t , carbohydrate, calcium and probably phosphorous f o r maintenance. Carex stans Drej values are equally as high as willow but not being a woody plant, chemical degeneration probably would be greater and hence the sedge would be of lower food value. D i s t r i b u t i o n The d i s t r i b u t i o n and abundance of any mammal are governed by many i n t e r a c t i n g c h a r a c t e r i s t i c s of the animal and i t s environment; certain fundamental requirements are necessary f o r sustained l i f e . In A r c t i c regions the number of ecological niphes i s often very l i m i t e d f o r mammals and consequently v a r i e t i e s are scarce. The number of genera" of resident t e r r e s t r i a l mammals north of t r e e l i n e i n the Canadian A r c t i c , f o r example, i s only about 19 (Anderson, 1946) i n an area of about one m i l l i o n square miles. Where l i f e circumstances are favourable, a species may number i n the thousands of i n d i v i d u a l s but apparently the muskox was never p a r t i c u l a r l y abundant though widely d i s t r i b u t e d (Hone, 1934), This possibly may be attr i b u t e d to the d i r e c t effect of the harsh A r c t i c climate on muskox s u r v i v a l i n winter, to the i n d i r e c t effect of climate on food plant occurrence and growth, to the low reproductive perform-ance of the species, to predation, or to some density dependent f a c t o r . The information about muskox d i s t r i b u t i o n obtained by the various methods outlined previously i n t h i s thesis indicates that the t o t a l population of muskoxen i n Canada today i s about 5,000, Of t h i s number about 1,500 are on the mainland and the rest on - 140 v a r i o u s i s l a n d s as discussed e a r l i e r . D i f f e r e n c e s between these f i g u r e s and those of Anderson (1930) given i n an e a r l i e r s e c t i o n of t h i s t h e s i s r e f l e c t a more accurate assessment of Canadian muskox p o p u l a t i o n s . A e r i a l and ground a c t i v i t i e s i n recent years i n the Northwest T e r r i t o r i e s have provided b e t t e r data upon which to estimate numbers and d i s t r i b u t i o n of the animals. T h e i r d i s t r i b u t i o n on the mainland r e f l e c t s s l o w l y i n c r e a s i n g and expanding groups, o f t e n i s o l a t e d , a f t e r 55 years of hunting f o r hides and meat and the subsequent 42 years of p r o t e c t i o n . Parts of t h e i r former range, such as t h a t i n the Yukon, probably never w i l l be restocked n a t u r a l l y b.ecause of e c o l o g i c a l b a r r i e r s and b a r r i e r s created by man. Undoubtedly they could be r e - e s t a b l i s h e d s u c c e s s f u l l y i f s m a l l groups were introduced i n t o former ranges and given p r o t e c t i o n from predators, i n c l u d i n g man, during the f i r s t years of establishment. Other regions now devoid of muskoxen, such as the Dubawnt and Kazan r i v e r v a l l e y s , and the country east of Bathurst I n l e t should e v e n t u a l l y be restocked by n a t u r a l spread. The recent d e c l i n e i n c a r i b o u numbers ( B a n f i e l d , 1956) may have a s e r i o u s e f f e c t on muskoxen f o r Eskimos must seek a l t e r n a t i v e sources o f food when they cannot f i n d c a r i b o u , Clarke (1940) f o r e c a s t t h i s danger. S t r i n g e n t .enforcement w i l l be r e q u i r e d f o r adequate pro-t e c t i o n . There i s no suggestion as yet t h a t muskoxen have reached den-s i t i e s exceeding t h e ^ a ^ r y i n g c a p a c i t y of the ranges on the mainland, although t h i s aspect must be i n v e s t i g a t e d much f a r t h e r before d e f i -n i t e conclusions may be drawn. As they do not appear to move long d i s t a n c e s t o s a t i s f y w i n t e r and summer range requirements, the - 141 number any area can support i s probably small. In addition, as demonstrated earlier i n this thesis, food production generally i s low on the winter ranges and the nutritive value of the winter foods particularly has not been found high. On some Arctic islands where muskoxen were k i l l e d for food and hides, the populations are increasing, although i t i s difficult to judge the residual numbers at the time hunting ceased i n 1917• It i s known that the American Arctic explorer, Robert E. Peary, k i l l e d many muskoxen (about 600) i n the Lake Hazen region of northern Ellesmere Island prior to 1909, yet today about two hundred exist there. The situation on Banks Island i s more obscure; they appeared at the north end of the island after an absence of records for 39 years. The recent sightings may have been the result of an influx of a group from another island, such as Melville, or may reflect the increase of a remnant herd. On Arctic islands where muskoxen have been hunted relatively l i t t l e , they have probably reached an equilibrium with their en-vironment. There i s a suggestion that on Prince Patrick Island their food requirements may have exceeded winter range production, as dead animals which appeared to have starved were found there i n late winter, and as indicated previously, the species has virtually and rapidly disappeared from the island since 1947. Contributing causes may have been a series of dry years, providing insufficient moisture for plant survival or possibly a series of winter sleet storms covered vegetation with a thick coating of ice preventing use by muskoxen. On Cornwallis Island a cow muskox was also found dead, which i n the opinion of the local R.C.M. Police officer died «• 142 ** from s t a r v a t i o n because of a hard snow cover over v e g e t a t i o n . Apart from the immediate e f f e c t s of seasonal changes i n the environment, the recent warming t r e a d i n the A r c t i c . c l i m a t e may be i n f l u e n c i n g animal d i s t r i b u t i o n and numbers i n ways not yet apparent. Future s t u d i e s may shed l i g h t on the degree of t h i s i n f l u e n c e on muskoxen. Reproduction and P o p u l a t i o n Increase Information obtained during the present study suggests t h a t the peak of the r u t occurs i n the t h i r d week of August, and t h a t the season probably extends two weeks e i t h e r s i d e of t h a t time. C a l v i n g appears to occur from the l a s t week i n A p r i l to the end of May, suggesting a g e s t a t i o n p e r i o d of about ei g h t t o nine months. References i n the l i t e r a t u r e i n d i c a t e t h a t mating times are s i m i l a r throughout Canada and Greenland, as are c a l v i n g times. Greely (1894), Sverdrup (1904) and Ekblaw (1918) who were on E l l e s m e r e I s l a n d , Storkerson (1920) who was on M e l v i l l e I s l a n d , Pedersen .(1958) and Vibe (1954) who s t u d i e d Greenland muskoxen, and Clarke (1940) who worked i n the Thelon Game Sanctuary, have found s i m i l a r c a l v i n g and mating p e r i o d s . The t i m i n g of the mating season i n muskoxen was discussed by Tener (1954) who p o s t u l a t e d a photoperiodic mechanism, a c t i n g during the v e r n a l equinox, as the r e g u l a t o r y f a c t o r producing a s i m i l a r breeding season among animals l i v i n g under q u i t e d i f f e r e n t regimes o f l i g h t . Such a mechanism had been p o s t u l a t e d e a r l i e r as i n -f l u e n c i n g r e p r o d u c t i o n i n s e v e r a l orders of mammals by other writers (Hart, 1950, Bissonnette and Csech, 1937 e t c . ) . Experimental t e s t -i n g of t h a t hypothesis w i t h muskoxen would be u s e f u l . - 143 -Storkerson (1920) has a t t r i b u t e d the death of some calves to t h e i r b i r t h s i n A p r i l when wi n t e r c o n d i t i o n s s t i l l p r e v a i l . Green forage does not appear i n the Thelon area u n t i l e a r l y June and i n the high A r c t i c u n t i l the l a t t e r h a l f of th a t month. The i n f l u e n c e of c l i m a t e and w i n t e r range food on the s u r v i v a l of calves cannot be too great or otherwise one might expect s e l e c t i o n i n favour of l a t e r c a l v i n g by the e l i m i n a t i o n of e a r l y breeders i n the p o p u l a t i o n , A.number o f authors have commented upon the frequency of muskox c a l v i n g , Jensen (1904), Freuchen (1915), Hennessy (1920), Johansen (1920), C r i t c h e l l - B u l l o c k (1930), Clarke (1940) and others b e l i e v e t h a t muskox cows c a l v e i n a l t e r n a t e y e a r s . I f a newly born c a l f d i e s soon a f t e r b i r t h , then i t may be p o s s i b l e f o r the cow to con-c e i v e i n the same year and to produce a c a l f the f o l l o w i n g s p r i n g , Pedersen 0.958) b e l i e v e s that the r e p r o d u c t i v e r a t e i s due d i r e c t l y to winter feed supply and summer c l i m a t e . I f a cow i s i n poor n u t r i t i o n a l c o n d i t i o n at the beginning of the r u t , according to Pedersen, she does not come i n t o heat. On the other hand, i f she enters the r u t i n good c o n d i t i o n , she may produce a c a l f every year and o c c a s i o n a l l y t w i n s. Hone (1934) c i t e s a number of observ-a t i o n s of twins and one case was observed at A l e r t , Ellesmere I s l a n d , i n 1952, by Mr. P i e r r e Gadbois (pers. comm.), A d o u b t f u l case of t w i n calves was recorded by me a t Lake Hazen i n 1958, when a herd was under o b s e r v a t i o n f o r s e v e r a l days. The two calves of equal s i z e i n the herd moved everywhere together, but when the herd was alarmed, the cal v e s e i t h e r r an t o the same cow or, f r e q u e n t l y , s p l i t up and ran to d i f f e r e n t cows. - 144 -The i n f l u e n c e of the n u t r i t i o n a l s t a t e of the female on p r o d u c t i v i t y of c a t t l e has been s t u d i e d f o r many years. I t i s a w e l l recognized f a c t t h a t h a l f starved animals are r e l a t i v e l y i n f e r t i l e (Maynard and L o o s l i , 1956). A s d e l l (1949) p o i n t s out that e a r l y m a l n u t r i t i o n prevents the o r d e r l y growth of the r e -productive organs as a p h y s i o l o g i c a l l y i n t e g r a t e d system, delaying puberty i n both males and females. I n o l d e r animals under-n u t r i t i o n r e s u l t s i n i r r e g u l a r heat periods and low f e r t i l i t y . D e f i c i e n c i e s of phosphorous, p a r t i c u l a r l y when a s s o c i a t e d w i t h a low p r o t e i n i n t a k e and a calcium d e f i c i e n c y , have been a t t r i b u t e d to be the cause, i n p a r t , of poor re p r o d u c t i o n i n range herds i n C a l i f o r n i a (Hart and G u i l b e r t , 1928). Poor breeding performance was report e d i n Minnesota by E c k l e s , Beaker and Palmer (1926) who found t h a t on many farms not more than one c a l f was obtained every two years and t h a t h e i f e r s sometimes d i d not come i n heat u n t i l they WBce over two years of age. I n t h a t study, and another by E c k l e s , G u l l i c k s o n and Palmer (1932), a d e f i c i e n c y of phosphorous was a t -t r i b u t e d to be the causal f a c t o r i n poor p r o d u c t i v i t y of cows. I n the l a t t e r study i t i s i n t e r e s t i n g to note the authors found th a t cows a f f e c t e d by a phosphorous d e f i c i e n c y tended to have one or two heat periods a f t e r they calved. I f they became pregnant a t t h i s time, the calves were c a r r i e d to term. I f not, they tended to show anoestrum f o r the r e s t of t h e i r l a c t a t i o n ; a f t e r d r y i n g o f f , heat periods returned and they had a normal chance of con-c e p t i o n . Palmer (1941) and R i d d e l l (1935) found th a t o v u l a t i o n occurred w i t h absence of heats i n cows on a phosphorous d e f i c i e n t r a t i o n , and Palmer a l s o found a delayed f i r s t heat i n h e i f e r s . - 145 -A s d e l l (op. c i t . ) summarizes by saying t h a t i t appears that a phosphorous d e f i c i e n c y i n t e r f e r e s w i t h o v a r i a n f u n c t i o n , probably causing a lowered oestrogen s e c r e t i o n i n the e a r l y stages. I n more severe c o n d i t i o n s , f o l l i c u l a r development i s i n t e r f e r e d w i t h . Studies c a r r i e d out by Cheatum and Severinghaus (1950) on w h i t e - t a i l e d deer (Odocoileus v i r g i n i a n u s ) i n d i c a t e d a r e l a t i o n -s h i p between the l e v e l of n u t r i t i o n of the does and. the number and frequency of t h e i r o f f s p r i n g . The b e t t e r the food, the gr e a t e r the number of twins produced and the l a r g e r the percentage of fawns co n c e i v i n g . The work c a r r i e d out by Robinette, et a l , (1955), sug-gests the p o s s i b i l i t y t h a t the n u t r i t i o n a l s t a t e of the mother may i n f l u e n c e the v i g o r of the fawn a t i t s b i r t h as w e l l as the n u t r i -t i v e value of her m i l k . The i n f o r m a t i o n gathered i n t h i s study suggests t h a t the n u t r i t i v e values of muskox food species are adequate f o r mainte-nance of l i f e , i f standards f o r l i v e s t o c k or deer are used as a ba s i s f o r e v a l u a t i o n . The low values of phosphorous and p r o t e i n found i n p l a n t s from w i n t e r ranges examined i n the Thelon Game Sanctuary, however, would suggest t h a t the r e p r o d u c t i v e performance of muskoxen there may be lower than' what i s g e n e t i c a l l y p o t e n t i a l l y p o s s i b l e . Two species of win t e r forage a t Lake Hazen w h i l e l i m i t e d i n extent, are b e t t e r sources of n u t r i e n t s f o r pregnant cows, par-t i c u l a r l y i n t h e i r phosphorous v a l u e s . I t was demonstrated e a r l i e r , however, t h a t the amount of food produced by Lake Hazen ranges i s very low and i t i s p o s s i b l e t h a t the n u t r i t i o n of a d u l t s s u f f e r s a c c o r d i n g l y . 146 -The low frequency of calves i n muskox populations under study, the apparent f a i l u r e of i n d i v i d u a l a d u l t cows to breed every year, the m a r g i n a l ' q u a l i t y and l i m i t e d amounts of w i n t e r foods and the known r e l a t i o n s h i p between n u t r i t i o n and re p r o d u c t i o n suggest t h a t food i s a f a c t o r c o n t r o l l i n g the r e p r o d u c t i v e r a t e of muskoxen. The comparison of mean summer herd s i z e s of the Thelon Game Sanctuary and of Ellesmere I s l a n d cannot be t e s t e d s t a t i s t i c a l l y beeause of sampling e r r o r s . The means do suggest, however, t h a t Thelon herds i n summer are larger,and t h a t there was no d i f f e r e n c e between mean herd s i z e s found i n w i n t e r i n the two areas. Much l a r g e r herds were found i n both summer and w i n t e r i n the Thelon area, which may r e f l e c t l e s s need f o r d i s p e r s a l i n the se a r c h f o r food. The gr e a t e r v e g e t a t i v e cover and greater annual production of food species demonstrated i n the Thelon area would permit a l a r g e r c a r r y i n g c a p a c i t y . Animals on Ellesmere I s l a n d s t i l l herd together f o r group p r o t e c t i o n , but p o s s i b l y are l i m i t e d i n herd s i z e by food r e s t r i c t i o n s . The l a r g e seasonal d i f f e r e n c e i n the number of observations of s o l i t a r y b u l l s between summer and w i n t e r may r e f l e c t a seasonal d i f f e r e n c e i n n e c e s s i t y f o r p r o t e c t i o n from predators. Food i s sc a r c e r f o r wolves i n w i n t e r and i t i s conceivable t h a t they i n -crease t h e i r p r e d a t i o n pressure a g a i n s t muskoxen a t t h a t time. A second f a c t o r may be the p r o t e c t i o n an animal gets by being a member of a group when severe w i n t e r storms occur. A t h i r d , and probably most important f a c t o r , i s t h a t when re p r o d u c t i v e hormone l e v e l s are high i n summer, the b u l l s tend to shun one another. ~ 147 -Because the c a l f crop data were not gathered under uniform c o n d i t i o n s each year, i t i s not p o s s i b l e to compare populations s t a t i s t i c a l l y . The data i n Tables XXI and XXV do suggest, however, t h a t a higher percentage of calves i s produced by muskoxen i n the Thelon Game Sanctuary than by those on Ellesmere I s l a n d . I n both areas, however, the observations o f one year revealed no c a l v e s . The sample s i z e i n the Thelon area i n 1957 was only 63 animals and may not have been l a r g e enough to r e f l e c t the t r u e c a l f crop. At Eureka, however, the sample of 150 animals observed i n 1954 r e p r e -sented n e a r l y the e n t i r e l o c a l p o p u l a t i o n . I t i s not known what f a c t o r or f a c t o r s c o n t r i b u t e to t h e absence of c a l v e s . Severe weather at b i r t h , heavy wolf p r e d a t i o n , f a i l u r e of cows to conceive or to b r i n g calves t o term, may s i n g l y or together r e s u l t i n no calves s u r v i v i n g the f i r s t month of l i f e . The observations of Vibe (1954) shed some l i g h t on the absence of calves i n c e r t a i n high A r c t i c regions' i n 1954 f o r he found no calves i n 350 muskoxen during an a e r i a l s e arch f o r muskox calves i n the summer of t h a t year on the east coast of Greenland i n the Scorsby sound area. Vibe a t t r i -buted the absence of calves and the death of other animals to s t a r v a t i o n , brought about by an un u s u a l l y deep s n o w f a l l which covered w i n t e r pastures w i t h a l a y e r one to fo u r meters i n depth over vast areas of the coast. I n a d d i t i o n , s p e l l s of m i l d weather i n November, 1953, and i n February, 1954, produced an i c e c r u s t which eovered the e n t i r e east coast of Greenland. Vibe concluded t h a t the c a t a s t r o p h i c w i n t e r of 1953-54, i n which he reported many hundreds of muskoxen peris h e d , was a r e s u l t of the warming t r e n d i n the A r c t i c c l i m a t e and tha t s i m i l a r catastrophes w i l l occur. - 148 -An examination of the m e t e o r o l o g i c a l data obtained a t the Eureka weather s t a t i o n by the Department of Transport r e v e a l s that there were no unusual weather c o n d i t i o n s i n t h a t area during the wi n t e r of 1953-54 to which could be a t t r i b u t e d the absence of calves. Some other f a c t o r must be considered, as i n d i c a t e d e a r l i e r i n t h i s d i s c u s s i o n , but there are i n s u f f i c i e n t data t o examine the s i t u a t i o n f u r t h e r . By most ungulate standards, muskoxen produce few c a l v e s , B a n f i e l d (1954) found the r a t i o of calves i n herds of barren-ground c a r i b o u segregated i n summer to be between 17 and 24.9 per cent. The annual c a l f increment to t h e herds under study was c a l c u l a t e d to be 21.6 per cent. K e l s a l l (1957) i n f u r t h e r s t u d i e s of the species, found the per cent of calves to vary annually. I n the Rae herd, the p r o p o r t i o n v a r i e d between 6.7 per cent i n the w i n t e r of 1951-53 to 28.5 per cent a year l a t e r . During the same p e r i o d a e r i a l counts of c a l v e s i n the Great Bear herd ranged between 15.1 per cent and 20.6 per cent. F u l l e r ( i n press) found t h a t b i s o n (Bison b i s o n b i s o n X B.b.  athabascae) calves i n Wood B u f f a l o N a t i o n a l Park c o n s t i t u t e d 20 to 25 per cent of herd s t r e n g t h immediately a f t e r the c a l v i n g season ( e a r l y J u l y ) but l e s s than 10 per cent by l a t e w i n t e r . Couey (1950) has reported an average lamb crop of 26 per cent d u r i n g the 1942-43 w i n t e r observations of mountain sheep (Ovis  canadensis spj i n Montana. Cowan (1943) noted t h a t 29 lambs were seen w i t h 37 ewes examined a f t e r the lambing season ended i n Banff N a t i o n a l Park, a percentage of 78.3, I n 1944 be reported t h a t the C a i r n Pass band i n Jasper N a t i o n a l Park i n 1943 contained a lamb-ewe - 149 -r a t i o of 14 per cent, but i n 1944 a r a t i o of 44 per cent. The 1944 r a t i o of Athabasca V a l l e y bands i n that park was 34 per cent. Flook (1955) r e p o r t e d t h a t on the Brazeau watershed of Jasper Park lambs c o n s t i t u t e d 29 per cent o f a l l animals i n the bands sexed and aged. He was not able to get a lamb-ewe r a t i o . Information about the p r o p o r t i o n of calves at the end of t h e c a l v i n g season i n most Cervidae i s u s u a l l y l i m i t e d to cow-calf per-centages because of the s e p a r a t i o n of the sexes at t h a t time and because of the s o l i t a r y h a b i t s of many of the males. For t h i s reason i t i s not p o s s i b l e t o compare muskox c a l f percentages w i t h most of the d a t a r e l a t i n g to c e r v i d s . Pre-hunting season data are a v a i l a b l e , however, f o r some white- t a i l e d deer populations, which provide a measure of deer p r o d u c t i v i t y . Dahlberg and Guettinger (1956) i n t h e i r study of those deer i n Wisconsin, found t h a t over a p e r i o d o f 11 years fawns averaged 39 per cent i n herds censused. The end-of-the-year fawn composition i n f o u r mule deer herds i n four s t a t e s of western United States was reported by Robinette (1956) to vary between 30.5 and 45.3 per cent. The r a t e of i n c r e a s e i n e l k was discussed by Murie (1951). Again c a l f percentages were based on i n f o r m a t i o n gathered during the hunting season or during c l a s s i f i e d counts i n mid-winter, w i t h i n , and j u s t north o f , Yellowstone Park. The average c a l f crop over a s i x year p e r i o d north of the park was 16.3 per cent, a c c o r d i n g to hunter k i l l data. I n the Jackson Hole herd to the south winter counts revealed an average c a l f r a t i o of 18.8 per cent. Cowan (1943) r e p o r t e d t h a t 48 per cent of a d u l t cows i n Banff N a t i o n a l Park i n 1943 had c a l v e s . Expressed d i f f e r e n t l y , calves were 21 per cent of a l l animals seen. - 150 -Peterson (1955) t a b u l a t e d data gathered from numerous sources about the summer age composition of moose p o p u l a t i o n s . The per cent calves of a d u l t s i n moose populations i n Banff, Jasper and Kootenay N a t i o n a l Parks ranged between eight and 43 per cent, i n Montana was 21 per cent and gave a three year average i n Ontario o f 22 per cent. There i s a p a r a l l e l i n the d i f f e r e n c e s i n the r a t i o of year-l i n g s i n muskox populations and i n those of other ungulates, B a n f i e l d (op, c i t , ) , f o r example, found t h a t y e a r l i n g s i n summer c o n s t i t u t e d between 8,9 and 12,9 per cent of herds. P u l l e r ' s (op, c i t , ) data i n d i c a t e d t h a t y e a r l i n g s composed seven t o nine per cent of b i s o n herds segregated. Comparable data f o r deer are d i f f i c u l t to o b t a i n because most researches group y e a r l i n g s and a d u l t s t o -gether, Murie((op, c i t , ) b e l i e v e d t h a t about one t h i r d of the i d e a l e l k c a l f crop (one c a l f f o r each cow) reached 10 months of age. Cowan (1945) found t h a t e l k y e a r l i n g s i n Banff N a t i o n a l Park i n the s p r i n g of 1945 were 14 per cent of a l l animals and i n 1946, i n Jasper N a t i o n a l Park, were 11 per cent (Cowan, 1946), H i s 1943 s t u d i e s a t Banff N a t i o n a l Park r e v e a l e d that y e a r l i n g s were 20 per cent of the cows, Peterson's (op, c i t . ) t a b u l a t i o n of moose data shows y e a r l i n g percentages of a d u l t s ranging between 6 and 12 i n the western n a t i o n a l parks, 16 i n Montana, between 10 and 22 w i t h a 19 per cent three year average i n Newfoundland, and a 16 per cent three year average i n O n t a r i o , The data a v a i l a b l e suggest t h a t roughly one t h i r d of b u f f a l o calves (and p o s s i b l y e lk calves) s u r v i v e to t h e y e a r l i n g stage. The s u r v i v a l of moose calves to y e a r l i n g s d i f f e r e d somewhat i n - 151 d i f f e r e n t areas and i n d i f f e r e n t years, as might be expected, Peterson quotes Cowan's f i g u r e s f o r Jasper N a t i o n a l Park, where there was a 75 per cent s u r v i v a l i n 1943 and a 57 per cent s u r v i v a l i n 1944, He a l s o quotes data from Alaskan s t u d i e s which i n d i c a t e d a 75 per cent s u r v i v a l up t o midwinter. The combined s u r v i v a l r a t e i n . Peterson's data was 71 per cent. Y e a r l i n g t o lewe percentages i n the Athabasca V a l l e y bands i n Jasper N a t i o n a l Park were given by Cowan (1946) f o r the years- 1943 to 1946 i n c l u s i v e , and were as f o l l o w s : 18, 30, 43 and 25 per cent. The 1943 f i g u r e s were obtained i n summer but those of subsequent years were May counts. I n 1944 Cowan (1944) found t h a t c e r t a i n bands of the Athabasca V a l l e y e x h i b i t e d poor s u r v i v a l to y e a r l i n g age, some bands c o n t a i n i n g few or no y e a r l i n g s . I n Banff N a t i o n a l Park i n 1943, Cowan found t h a t y e a r l i n g s comprised 26 per cent of the a d u l t ewe po p u l a t i o n but only 15 per cent of the t o t a l popula-t i o n sexed and aged. Couey's (1950) f i g u r e of the Montana popula-t i o n y e a r l i n g percentage was 9, but h i s counts were taken i n winter. P r e l i m i n a r y i n f o r m a t i o n i n d i c a t e s t h a t muskox c a l f s u r v i v a l i s b e t t e r than t h a t of b u f f a l o i n Wood B u f f a l o Park, p o s s i b l y because the b r u c e l l o s i s i n c i d e n c e i n b u f f a l o may reduce c a l f v i a b i l i t y . Novakowski (ms. r e p o r t , 1958) has commented on tha t aspect of buf-f a l o c a l f s u r v i v a l . Moose c a l f s u r v i v a l , however, i s g r e a t e r than t h a t of muskoxen. The r e l a t i v e l y good muskox c a l f s u r v i v a l i s somewhat s u r p r i s i n g i n view of the harsh environment calves must endure, p a r t i c u l a r l y i n w i n t e r . I t i s a product, perhaps, of maternal s o l i c i t u d e , herd p r o t e c t i o n from predators and a v a i l a b i l i t y of adequate food, - 152 -i n c l u d i n g m i l k from the mothers. Prolonged l a c t a t i o n , evidence of which was found by Freuchen (1915), Pedersen (1936) and by the author i n the present study, may serve the purpose of supplementing forage the calves o b t a i n during the c r i t i c a l w i n t e r months of t h e i r f i r s t year of l i f e , thus a i d i n g s u r v i v a l . T h e o r e t i c a l c o n s i d e r a t i o n of the i n t r i n s i c r a t e of n a t u r a l i n c r e a s e .  Mr. P.H. L e s l i e , the eminent B r i t i s h b i o m e t r i c i a n of the Bureau of Animal P o p u l a t i o n , Oxford, i n 1953,prepared, at my r e -quest, a t h e o r e t i c a l e v a l u a t i o n of the r a t e at which a p o p u l a t i o n o f muskoxen would i n c r e a s e . The c o n s i d e r a t i o n was based on b i o l o -g i c a l data I f u r n i s h e d him and i s given i n Appendix I I as a theo-r e t i c a l parameter around which e x p l o i t a t i o n of the species might be considered. When s p e c i f i c l i f e t a b l e s have been prepared, a more r e a l i s t i c a p p r a i s a l of p o p u l a t i o n i n c r e a s e can be formulated, f o r L e s l i e ' s d i s c u s s i o n contains many assumptions which do not p e r t a i n to the l i v i n g animal. Adaptations of the muskox to the A r c t i c Environment. Animals l i v i n g i n A r c t i c regions have adapted i n a number of ways to the r i g o r s of the tundra environment. Nearly a l l b i r d s which occupy v a r i o u s niches i n the tundra f o r n e s t i n g and r a i s i n g young migrate t o warmer southern regions before w i n t e r a r r i v e s . Exceptions are;, rock ptarmigan and, i n areas where some day l i g h t occurs d a i l y , w i l l o w ptarmigan, ravens, g y r f a l c o n s and snowy owls which e x i s t when food i s a v a i l a b l e . The ground s q u i r r e l ( C i t e l l u s  p a r r y i i p a r r v i i (Richardson) hibernates during w i n t e r months and the g r i z z l y (Ursus a r c t o s r i c h a r d s o n i Swainson) undergoes what - 153 -Hock (1958) has r e f e r r e d to as "carnivorean l e t h a r g y " f o r some f i v e months duri n g t h a t c o l d season. Caribou o c c a s i o n a l l y w i n t e r on the tundra i n r e l a t i v e l y s m a l l groups but most i n d i v i d u a l s on the A r c t i c mainland migrate t o timbered regions t o the south. On the i s l a n d s , however, ca r i b o u remain i n the tundra biome during w i n t e r . Small mammals such as lemmings (Dicrostonyx sp. and Lemmus sp.) and weasels (Mustela) are a c t i v e throughout the w i n t e r under the snoTf cover. Along w i t h hares (Lepus a r c t i c u s ) , foxes (Alopex s p . ) , some wolverines (Gulo luscus luscus (Linnaeus), some wolves (Canis lupus) and those c a r i b o u on the Arctic" I s l a n d s , muskoxen are tundra d w e l l e r s the year round, and so must be a b l e to get t h e i r l i f e requirements even i n the depths of w i n t e r . The number of ways i n which muskoxen have adapted t o l i v e s u c c e s s f u l l y i n the A r c t i c the year round are explored i n t h i s s e c t i o n . Three kinds of adaptations w i l l be d i s -cussed, b e h a v i o u r a l , p h y s i o l o g i c a l and morphological. Before pro-ceeding w i t h the d i s c u s s i o n s , however, i t would be d e s i r a b l e to r e c a l l the s t r u c t u r e of an adult muskox. I t i s a comparatively l a r g e ungulate, a b u l l weighing 700-900 pounds. I t has a short t a i l covered completely by the body h a i r and i t s limbs are short and heavy. The animal i s covered, except: f o r i t s nose and eyes, by f i n e dense i n n e r h a i r and a coat of long outer coarse h a i r . I t s f r o n t -hoofs are l a r g e r than i t s hindhoofs. The c a r r i a g e of i t s l a r g e head ,'in a depressed p o s i t i o n ! suggests a g r a z i n g animal, s u i t e d to f o r a g i n g on low growing p l a n t s such as chamaephytes, hemicryptophytes and geophytes, but a l s o suggests t h a t the s t r u c t u r a l l y rugged head and horns are adaptations f o r defensive and o f f e n s i v e purposes. 154 * Behavioural Adaptations A s t r i k i n g f e a t u r e of the tundra i s the absence of v e g e t a t i v e cover f o r escape of l a r g e r animals. An ungulate, f o r example, e i t h e r must be f l e e t enough to escape predators, r e l y on the s a f e t y -in-numbers concept or possess means of i t s own to r e p e l a t t a c k e r s . The muskox f a l l s i n t o the l a t t e r category. The sharp , massive horns of muskoxen are formidable weapons agai n s t a s i n g l e wolf but there i s l i t t l e p r o t e c t i o n a g a i n s t a t t a c k s from the r e a r . The herd defense system discussed i n the behavioural s e c t i o n of t h i s t h e s i s over-comes t h a t weakness and i s an e f f e c t i v e adaptation to predatory attempts by wolves under c o n d i t i o n s where prey can be detected f o r many m i l e s and no escape cover i s a v a i l a b l e . When alarmed to pos-s i b l e danger by a i r c r a f t , v e h i c l e s or a walking man, muskoxen o f t e n run and may do so s u r p r i s i n g l y q u i c k l y and. i f a b l e , w i l l i n v a r i a b l y head f o r high ground. A herd w i l l reform there, commanding a wide view of approaches to i t from a l l s i d e s . As p r e v i o u s l y pointed out, the existence of herd u n i t s keeps the sexes together d u r i n g the mating season, where otherwise the animals sparseness i n a vast country might r e s u l t i n f a i l u r e of cows to breed. Herd behaviour undoubtedly a s s i s t s the s u r v i v a l of young animals f o r the knowledge of f e e d i n g areas, p a r t i c u l a r l y i n w i n t e r , h e l d by o l d e r , experienced i n d i v i d u a l s would be passed on to the immature groups. Previous s e c t i o n s of t h i s t h e s i s have revealed the sparseness of v e g e t a t i o n on muskox ranges and muskox fe e d i n g h a b i t s have been examined. I t i s obvious t h a t w h i l e the species has d e f i n i t e pre-ferences f o r c e r t a i n p l a n t s such as w i l l o w and sedges, i t s food i s - 155 -not confined to those plants but i t w i l l eat a considerable number of different forms, including grasses, forbs and woody-species. Were i t otherwise, i t is doubtful i f muskoxen could survive in the Arctic where annual production of food i s so low. It has been indicated in previous sections that large con-centrations of muskoxen, such as herds of several hundred or more, do not exist. The barren ground caribou, the other large ungulate of the Arctic, does occur in large herds, but the essential be-havioural difference i s that caribou are migratory and so do not depend on a given area of the tundra for winter subsistence. Musk-oxen, which forage over a much smaller area and which do not mi-grate to forested areas for winter, occur in widely scattered small herds. This behaviour, as postulated earlier, would have definite survival value in spreading range u t i l i z a t i o n by a population over a large area. This is true particularly for muskoxen of the Arctic Islands. Physiological and Morphological Adaptations. As a ruminant, the muskox possesses certain characteristics which enable i t to survive in the Arctic. The various B vitamins are produced in the rumen and hence are unnecessary in the diet and amino acid synthesis from existing nitrogenous materials by rumen microorganisms probably supplements any amino acid deficiency which might occur in food plants consumed. The muskox eye probably is typically ungulat©, possessing a duplex retina with a tapetum fibrosum for visual sensitivity during the long winter darkness. The eye also possesses an area centralis, or pure cone area for visual acuity, a desirable asset in open f l a t terrain, as well as corpora nigra and a s l i t pupil for reduction - 156 -of i n t e n s e i l l u m i n a t i o n , such as would occur during l a t e w i n t e r and s p r i n g . The present study has i n d i c a t e d t h a t other p h y s i o l o g i c a l adaptations e x i s t . The marked i n c r e a s e of l i v e r weights as the summer season progressed suggests t h a t food stored i n t h a t organ i s an important source of energy during w i n t e r months. The pro-d u c t i o n of m i l k w i t h a r e l a t i v e l y h i g h f a t content would a s s i s t calves to eope wi t h low temperatures and d r i e d forage u n t i l green v e g e t a t i o n of s p r i n g appeared. I n t h i s connection, the v i t a m i n A content of m i l k , e s s e n t i a l t o growth of young, would be important a l s o . Prolonged l a c t a t i o n by the muskox, which may continue u n t i l the c a l f i s a t l e a s t 15 months of age and perhaps longer, would provide supplemental food to the c a l f during periods of environ-mental s t r e s s and reduced food values and of great demands f o r n u t r i e n t s f o r growth during the w i n t e r months. The c h a r a c t e r i s t i c s described above are e s s e n t i a l l y those f o r coping w i t h l e s s n u t r i t i o u s and l e s s abundant food of w i n t e r . What are the adaptations of the i n d i v i d u a l animal to the c o l d of winter, which can be i n t e n s e and prolonged? Scholander, et a l (1950c) have i n d i c a t e d three p o s s i b l e avenues by which animals can adapt t o cold. These are 1. by l i v i n g i n areas where the body to a i r temperature gradient i s low, 2. by adjustment of the b a s a l metabolic r a t e and 3. by i n s u l a t i o n . I n A r c t i c r e g i o n s , the temperature gradient of mammals i s h i g h , reaching 160°-170°F. The average body temperature of s i x A r c t i c species ( p o l a r bear, A r c t i c f o x , A r c t i c hare, ground s q u i r r e l , c a ribou and reindeer) averaged 100.8°F. ( I r v i n g and Krog. 1954). The muskox body temperature of 100.6° found i n the present 157 -study indicates that i t s temperature has not been altered to adapt to the high thermal gradient existing i n winter and there-fore, has adapted to the cold by other means. As Irving and Krog (1954) point out, a l l of the Arctic mammals belong to systematic groups with extensive heat regulation and the level of regulation i s not affected by environmental temperature so different as those of Arctic winter and the hot summer of temperate regions. The body temperature of mammals i s a fundamental non-adaptive constant i n their biochemical makeup. Equally non-adaptive, according to Scholander, et a l (1950c) i s the basal metabolic rate of t e r r e s t r i a l mammals, Benedicts mouse to elephant curve indicates that the basal metabolic rate i s determined by body size irrespective of climate. Phylogenetic adaptation to cold therefore rests entirely on the plasticity of factors which determine the heat loss, mainly insulation. For any temperature gradient where the body temperature i s maintained the overall insulation and the metabolic rate must be so adjusted that their product i s proportional to that gradient. The above authors believe that a l l large mammals of the Arctic have a c r i t i c a l tem-perature ( i . e . an environmental temperature where metabolism must be increased to maintain body temperature) of between -45°C. and -50°C. If the c r i t i c a l temperature of muskoxen f a l l s within that range then there must be occasions when their metabolic activity would be increased frequently for temperatures exceeding the above minima are encountered often i n the Arctic. A factor not considered by the above authors i s windchill. Windchill expresses the rate at which the unclothed human body loses heat i f placed out-of-doors 158 -under given weather conditions. It i s measured i n units based on the amount of heat the atmosphere i s capable of absorbing an hour from an exposed surface one meter square at a temperature of 91.4°F. Windchill values have been calculated and these show that as much heat can be lost at 32°F. with 20 m.p.h. wind as at -25°F. with no wind (Siple and Passel ,;1945). Those data suggest that any consideration of the c r i t i c a l temperature of an Arctic mammal should also include the influence of windchill. Neither body temperature nor the basal metabolic rate of mammals i s altered to cope with heat loss. The third avenue for cold adaptation proposed by Scholander et a l (1950c), insulation, i s one we w i l l explore next. It has been pointed put by Scholander et a l (1950a) that as a means of conserving heat, the l i v i n g animal may vary the fur and skin insulation greatly by erecting the hairs, by vasomotor control of the skin and tissue temperature immediately under the fur, by changes i n evaporation,etc. A good correlation exists between fur thickness and i t s insulation value. There are also considerable regional differences i n heat loss of the body, legs and face. Such peripheral circulation control has been d emonstrated i n seals by Irving and Hart (1957). Cottle (1959) has reported lowered tem-peratures i n the skin of the feet of caribou calves; exposed to conditions of high heat loss, substantiating the belief of Scholander (1950) and of Scholander et a l (1950a) that the poorly insulated legs of Arctic animals i s probably a major factor i n heat regulation. Respiration, excretion and posture of an animal also are major factors i n determining total heat loss. - 159 -As y e t there i s very l i t t l e p r e c i s e i n f o r m a t i o n about the ways i n which muskoxen have adapted to c o l d . However, there are s e v e r a l p o s s i b l e a d a p t a t i o n which can be considered. Oneiis t h a t the muskox i s a good example of A l l e n 1 s Rule, f o r i t has short appen-dages. I t s t a i l i s about f o u r inches long and i t s limbs are short and stocky. C i r c u l a t i o n of blood from the body mass to the extrem-i t i e s of the limbs and back would be comparatively f a s t , reducing heat l o s s . Another p o i n t i s t h a t the muskox i s covered w i t h a dense mat of f i n e i n n e r h a i r and long outer guard h a i r s . The only bare s k i n i s a s m a l l patch on the nose. The i n n e r h a i r i s shed annually d u r i n g the s p r i n g and summer and presumably t h i s a i d s the animal i n coping w i t h the season's heat. By autumn the new h a i r has appeared and i t i s t h i s which probably provides most of the i n s u l a t i o n , f o r as Scholander et a l (1950a) p o i n t out f o r p o l a r bears, the coarse h a i r has poor i n s u l a t i n g q u a l i t i e s . Nevertheless, the long outer h a i r o f muskoxen probably provides some degree of i n s u l a t i o n . Examination of the photograph i n Pigure 26 r e v e a l s t h a t such h a i r hangs w e l l below the body and down the l e g s almost to the ankle s h i e l d i n g the g r e a t e r p a r t of the l i m b s . An a d d i t i o n a l means whereby energy may be conserved has been p o s t u l a t e d i n the s e c t i o n on f e e d i n g h a b i t s . Muskoxen u s u a l l y move sl o w l y and d e l i b e r a t e l y . Such a c t i o n s would tend t o reduce heat l o s s as w e l l as conserve energy. Another means of heat conserva-t i o n might be considered. I n w i n t e r no water i s a v a i l a b l e f o r d r i n k i n g and muskoxen and other animals consume snow. Heat would be r e q u i r e d f o r conversion of snow to water. The f a c t t h a t w i n t e r dung i s i n the form of dry, round p e l l e t s , i n c o n t r a s t w i t h the - 160 -l o o s e , s o f t m a t e r i a l of summer, suggests t h a t both water and heat are being conserved. Hart and I r v i n g (1959) have demonstrated seasonal changes i n the energetics of harbour s e a l s , based on metabolic responses to s k i n temperatures, i m p l y i n g g r e a t e r p e r i p h e r a l s t i m u l a t i o n of meta-boli s m i n summer. Bandy et a l (1957) r e f e r r e d b r i e f l y to a growth progression of Columbian b l a c k - t a i l e d deer, i n t e r r u p t e d during the w i n t e r p e r i o d by apparently homeostatic mechanisms t h a t are independent of n u t r i -t i o n a l plane and sexual a c t i v i t y , A s i m i l a r i n c r e a s e d metabolism may take place i n summer i n muskoxen and reduced metabolism may occur i n w i n t e r , I suggest t h a t f o r ungulates, and p o s s i b l e other mammals, a photoperiodic mechanism may operate, a c t i n g through the p i t u i t a r y on v a r i o u s hormones governing seasonal metabolism. I n h i s paper "The P o p u l a t i o n Consequences of L i f e H i s t o r y Phenomena", Cole (1954) s t r e s s e s the concept t h a t the such l i f e h i s t o r y f e a t u r e s o f a species as t o t a l f e c u n d i t y , maximum longevity and s t a t i s t i c a l a ge schedules of rep r o d u c t i o n and death are adapta-t i o n s r e l a t e d t o i t s requirements f o r l i v i n g and are subject to n a t u r a l s e l e c t i o n . A p o i n t he emphasizes i s t h a t the age a t which re p r o d u c t i o n begins i s one of the most s i g n i f i c a n t c h a r a c t e r i s t i c s of a species and t h a t i t , i n t e r a c t i n g w i t h the number of o f f s p r i n g produced, determine the i n t r i n s i c r a t e of n a t u r a l i n c r e a s e , A t h e o r e t i c a l c o n s i d e r a t i o n o f the i n t r i n s i c r a t e of n a t u r a l i n c r e a s e of muskoxen has been presented i n the appendix of t h i s t h e s i s where the consequences of the species c h a r a c t e r i s t i c of not c a l v i n g y e a r l y have been examined. I t i s suggested here t h a t the - 161 -low r a t e of i n c r e a s e of muskoxen has evolved i n an environment where m o r t a l i t y r a t e s are low and yet where food production a l s o i s low. I f m o r t a l i t y r a t e s i n c r e a s e d , the species would beeome e x t i r p a t e d or i f the i n t r i n s i c r a t e o f n a t u r a l i n c r e a s e were higher, the species p o p u l a t i o n would f i n d i n s u f f i c i e n t forage f o r l i v i n g and hence would become depleted or e l i m i n a t e d . The above p o s t u l a t i o n does not i n f e r t h a t there i s no p l a s t i c i t y i n the r e -p r o d u c t i v e r a t e . I t i s q u i t e p o s s i b l e t h a t given an abundance of h i g h l y n u t r i t i o u s food, muskoxen might c a l v e y e a r l y and as has been shown i n the Vermont s t u d i e s of John J . Teal ( p e r s . comm.), calv e at an e a r l i e r age, thus i n c r e a s i n g the i n t r i n s i c r a t e of n a t u r a l i n c r e a s e m a t e r i a l l y . Under the e c o l o g i c a l c o n d i t i o n s which w i l d muskoxen l i v e , however, the observed r e p r o d u c t i v e c h a r a c t e r i s t i c s probably have species s u r v i v a l v a l u e . C e r t a i n morphological c h a r a c t e r i s t i c s of muskoxen, such as short limbs and dense f u r have been considered above as adaptations to the A r c t i c w i n t e r . An a d d i t i o n a l f e a t u r e i s the l a r g e r s i z e of f r o n t hoofs of the animals. The greater s i z e suggests g r e a t e r ef-f i c i e n c y f o r d i g g i n g through snow during the nine months of w i n t e r . I n t h i s connection i t i s i n t e r e s t i n g to note t h a t McCann (1956), among ot h e r s , a t t r i b u t e s t h e greater s i z e of f r o n t hoofs of moun-t a i n sheep (Ovis canadensis subsp.) to adaptation f o r c l i m b i n g and f o r f a c i l i t a t i n g d i f f i c u l t descents. I t would be u s e f u l to compare mountain sheep and muskoxen f u r t h e r to b r i n g out adaptations of the l a t t e r to t h e i r environments. The mountain sheep of North America are animals of the western mountains. Both sheep and muskoxen belong to t h e f a m i l y Bovida.e - 162 -(Simpson, 1945), both have stocky b u i l d s , both are able to w i t h -stand low temperatures and a r i d c l i m a t e s , both forage i n w i n t e r i n areas where snow i s kept minimal by wind and both feed on a wide v a r i e t y of foods so t h a t t h e i r d i s t r i b u t i o n i s not r e s t r i c t e d by the l i m i t a t i o n of one or a few food s p e c i e s . I t i s i n t h e i r d i f f e r e n c e s , however, where adaptations of muskoxen t o the A r c t i c environment become more apparent. Muskoxen have a more dense f u r covering than sheep f o r obvious reasons. T h e i r d i s p o s i t i o n i s more phlegmatic and t h e i r movements u s u a l l y much more d e l i b e r a t e , which may r e s u l t i n heat and energy conserva-t i o n . Sheep tend to feed i n w i n t e r i n one r e s t r i c t e d area f o r pro-longed p e r i o d s , even to the serious d e s t r u c t i o n of p l a n t s p e c i e s . I t has been pointed out elsewhere i n t h i s t h e s i s t h a t muskoxen may spend one to s e v e r a l days f e e d i n g i n a r e s t r i c t e d r e g i o n but the d e s t r u c t i o n of forage species has not been observed to take p l a c e , because of t h e i r h a b i t of changing f e e d i n g s i t e s and because the numbers of muskoxen i n each herd are s m a l l . Sheep c h a r a c t e r i s t i c a l l y remain w i t h i n a short d i s t a n c e of t h e i r escape t e r r a i n , steep broken slopes o r c l i f f areas. As a r u l e they avoid broad open areas. Such behaviour i s p a r t of t h e i r escape p a t t e r n . When a band of sheep i s alarmed, the animals break away and f l e e i n d i v i d u a l l y to the nearest s l o p e , although Murie (1944) has recorded two in s t a n c e s where a band of rams bunched and faced approaching wolves. Often there i s no attempt by the rams to form p r o t e c t i v e guardianship. The s a f e t y of the i n d i v i d -u a l depends upon h i s a b i l i t y to reach p r e c i p i t o u s t e r r a i n before being caught. - 163 -Muskoxen are d w e l l e r s of r e l a t i v e l y f l a t country. If alarmed by a non-canid, they f r e q u e n t l y w i l l run as a c l o s e l y k n i t group to a nearby h i l l or i f none a v a i l a b l e , w i l l continue running u n t i l s e v e r a l m i l e s away. I f attacked by a wolf or dog, however, the animals immediately form t h e i r c h a r a c t e r i s t i c bunched defensive group and i n summer the b u l l s a c t i v e l y take the l e a d i n r e p e l l i n g a ggression. I n t h e i r remote past,:, ancestors of muskoxen may have been more c l o s e l y a s s o c i a t e d w i t h p r e c i p i t o u s country. E v o l u t i o n of the species may have taken them to open regions w i t h the con-sequent n e c e s s i t y f o r group p r o t e c t i o n . Today, muskoxen, by e v i n c i n g two escape pa t t e r n s i n response to d i f f e r e n c e s i n predators, such as man or wolf, may be r e f l e c t i n g an ancient a s s o c i a t i o n w i t h mountainous t e r r a i n . There i s no doubt t h a t group p r o t e c t i o n i n t h e i r environment i s e f f e c t i v e against wolves. Rams a s s o c i a t e w i t h ewes of sheep populations f o r a r e l a t i v e l y short time, l a t e November to mid-January when the r u t i s i n progress. At other times they form loose bands of t h e i r own sex. Muskox herds u s u a l l y c o n t a i n one or more b u l l s a t a l l seasons of the year, par-t i c u l a r l y i n w i n t e r . During the breeding season, one b u l l keeps a herd i n a harem-like manner, r e p e l l i n g a c t i v e l y the attempts of other b u l l s to acquire the herd. Sueh behaviour of b u l l s remaining more or l e s s w i t h herds of cows and immature animals has been pos-t u l a t e d e a r l i e r i n t h i s t h e s i s as s e r v i n g t o keep the sexes together f o r s u c c e s s f u l mating i n a r e g i o n so l a r g e t h a t the sexes might otherwise never meet. Mountain sheep lambs s u c k l e about f i v e months, muskox calves a t l e a s t 15 months. The longer p e r i o d has been p o s t u l a t e d to have — 164 s u r v i v a l value f o r calves f a c i n g the hardships of an A r c t i c w i n t e r T d a r k n e s s and r e l a t i v e l y scarce food. The present comparison has shown a few morphological, behavioural and p h y s i o l o g i c a l d i f f e r e n c e s i n adaptations to t h e i r environment between mountain sheep and muskoxen. Fur t h e r s t u d i e s w i l l l i k e l y show a d d i t i o n a l d i f f e r e n c e s , emphasizing adaptations of muskoxen to the A r c t i c environment. B i o l o g i c a l and Environmental F a c t o r s Involved i n Population Control E c o l o g i s t s have been concerned w i t h the t h e o r e t i c a l aspects of p o p u l a t i o n c o n t r o l i n animals f o r many y e a r s , a s c r i b i n g to the b i o l o g i c a l c h a r a c t e r i s t s of the species or to the i n f l u e n c e s of the environment, or to both (Thompson, 1939), the mechanisms whereby numbers of animals are l i m i t e d . Much of the l i t e r a t u r e , has d e a l t w i t h i n v e r t e b r a t e populations but some c o n s i d e r a t i o n has been given v e r t e b r a t e s , p a r t i c u l a r l y by Lack (1954), who suggested t h a t m o r t a l i t y may be i n f l u e n c e d by two f a c t o r s , proximate causes of death, such as the competition f o r a l i m i t e d number of refuges or f o r some other e s s e n t i a l l i f e requirement, and u l t i m a t e causes of death such as c o l d weather. Lack b e l i e v e s t h a t food i s a c r u c i a l f a c t o r i n the p r o d u c t i v i t y and s u r v i v a l of v e r t e b r a t e s . The c u r r e n t study of muskoxen has not provided c o n c l u s i v e evidence of a f a c t o r or f a c t o r s which could be s a i d to c o n t r o l t h e i r numbers, p r i n c i p a l l y because continous i n v e s t i g a t i o n of one group of animals over a p e r i o d of s e v e r a l years has not yet been undertaken. The f o l l o w i n g i s a d i s c u s s i o n of the i n f l u e n c e c e r t a i n f a c t o r s might have on Canadian muskox s u r v i v a l and increase. - 16*5 -Those f a c t o r s i n c l u d e c l i m a t e and the b i o t i c f a c t o r s of p r e d a t i o n , p a r a s i t e s 1 , diseases and competition f o r food. Climate U n t i l metabolic s t u d i e s are c a r r i e d out i t i s not p o s s i b l e to s t a t e c o n c l u s i v e l y what e f f e c t c l i m a t i c s t r e s s has on muskox metabolism. Adult muskoxen however, u s u a l l y withstand r e g u l a r l y the severest c l i m a t e t h e i r environment produces. At Lake Hazen, f o r example, temperatures below - 50°F. were recorded on 73 days durin g the w i n t e r of 1957-5$ and the temperature d i d not climb above zero Fahrenheit between October 21 and A p r i l 30 (Jackson, 1959). What i s probably more important to muskox s u r v i v a l i s the nature and depth of p r e c i p i t a t i o n . The h a b i t of the animals i n seeking areas of r e l a t i v e l y shallow snow cover to f e e d upon i n w i n t e r has already been d i s c u s s e d . P r e c i p i t a t i o n can have a c a t a s -t r o p h i c e f f e c t on muskox s u r v i v a l , an e f f e c t which i s independent of the animals. Vibe's (1954) r e p o r t of the s t a r v a t i o n of many hundreds of muskoxen i n the Scorsby Sound area of east Greenland has been discussed e a r l i e r i n t h i s t h e s i s . There are no instances of m o r t a l i t y of Canadian muskoxen from a s i m i l a r cause, probably because there are no p a r a l l e l s of weather systems moving over water from warmer regions to c o l d land masses as occurs i n east Greenland. The importance of snow depth i n ungulate m o r t a l i t y which has been recorded by many authors, has r e c e n t l y been reviewed by Edwards (1956). He was able t o s t a t e on the b a s i s of h i s s t u d i e s on moose i n c e n t r a l B r i t i s h Columbia t h a t w h i l e deep snow can r e s u l t i n con-s i d e r a b l e m o r t a l i t y , food and cover can modify the r e l a t i o n s h i p , p a r t i c u l a r l y when competition f o r those f a c t o r s i n an underpopulated - 168 -area i s minimal. P r u i t t (1959) has q u a n t i f i e d some of the charac-t e r i s t i c s of snow which i n f l u e n c e profoundly the behaviour, mi-g r a t i o n and s u r v i v a l of barren-ground c a r i b o u . S i m i l a r s t u d i e s on muskoxen probably w i l l show t h a t snow depth i s e q u a l l y as im-portant i n the s e l e c t i o n of feeding areas as snow t e x t u r e . The e f f e c t s of climate on Canadian muskoxen may be d i r e c t l y l e t h a l such as c o l d stormy weather when calves a r e born but more l i k e l y are i n d i r e c t by i n f l u e n c i n g the d i s t r i b u t i o n and growth of p l a n t s , t h e i r a v a i l a b i l i t y i n w i n t e r under snow, and the d i s t r i b u -t i o n of animals, such as wolves, which may a f f e c t the ungulates. Aside from short-term f a c t o r s of c l i m a t i c i n f l u e n c e s , l o n g -term changes i n the c l i m a t e of the A r c t i c such as the recent warming tr e n d may be causing changes i n muskox s u r v i v a l and mor-t a l i t y i n ways not yet evident. B i o t i c F a c t o r s The importance i n p o p u l a t i o n c o n t r o l , of b i o t i c f a c t o r s such as p r e d a t i o n , p a r a s i t e s , diseases, competition f o r food and the rep r o d u c t i v e r a t e of the spe c i e s , i s d i f f i c u l t to assess. On those A r e t i c i s l a n d s where hunting pressure on muskoxen has been ne-g l i g i b l e o r - n on-existent, b i o t i c f a c t o r s may be c o n t r o l l i n g muskox numbers, f o r populations i n those areas have had t h e i r environmental and d e n s i t y r e l a t i o n s h i p s undisturbed by man. On the A r c t i c main-land and on c e r t a i n of the A r c t i c i s l a n d s , where se r i o u s or a n n i h i -l a t i v e hunting took p l a c e , muskox numbers today are not a t the point y e t where d e n s i t y dependent f a c t o r s such as food competition, appear to be l i m i t i n g the abundance of the s p e c i e s . Muskoxen popu-l a t i o n s of the Thelon Game Sanctuary or of Lake Hazen are examples. - 167 -P r e d a t i o n No evidence was obtained t o suggest t h a t p r e d a t i o n by wolves or other p o s s i b l e predators, apart from man, i s c o n t r o l l i n g muskox numbers. Only two instances of wolves k i l l i n g calves have been recorded during t h i s study. However, i t i s conceivable t h a t , i n view of the low c a l f p r o d u c t i o n found i n herds, even the k i l l i n g of one or two calves i n a herd may mean the d i f f e r e n c e between an increase of a p o p u l a t i o n o r otherwise, Much f u r t h e r study i s r e q u i r e d f o r a true assesssment of wolf p r e d a t i o n as a p o p u l a t i o n c o n t r o l f a c t o r . I t i s i n t e r e s t i n g t o note t h a t the herd o f muskoxen introduced t o w o l f - f r e e Nunivak I s l a n d o f f the west coast of Alaska i s c u r r e n t l y producing twice the p r o p o r t i o n of c a l v e s found i n Canadian herds (U.S. F i s h and W i l d l i f e S e r v i c e c o r r e s p . ) . A d i r e c t comparison cannot be made, however, because of b a s i c environmental d i f f e r e n c e s between the i s l a n d and A r c t i c Canada. P a r a s i t e s The helminth fauna of muskoxen i s a l s o f o u n d i n a l l of the ruminant hosts o f the Northwest T e r r i t o r i e s (Gibbs and Tener, 1958. See attached paper). There was no evidence which suggested t h a t the p a r a s i t e s were a f f e c t i n g the h e a l t h or l o n g e v i t y of the muskoxen examined. One might expect t h a t the normal p a r a s i t e host r e l a t i o n -s h i p s between muskoxen and t h e i r p a r a s i t e s have been s t a b i l i z e d f o r a long time. The i n t r o d u c t i o n o f new p a r a s i t e s , however, may prove f a t a l t o the host, as happened t o a young muskox brought to Vermont, U.S.A., i n 1954. The animal contracted Hemonchus p l a c e ! , the bovine s t r a i n of H. contortus confined t o temperate c l i m a t e s , and d i e d . 168 -Disease P r a c t i c a l l y nothing i s known about diseases of wiM' muskoxen, p r e s e n t i n g a f i e l d of f u r t h e r study. Because of the sparseness of the animals, i t i s u n l i k e l y on t h e o r e t i c a l grounds t h a t disease would have a widespread e f f e c t on the s p e c i e s , unless the disease were c a r r i e d by a wide-ranging a l t e r n a t i v e host such as the caribou or i n an abundant species such as the lemming or A r c t i c f o x . Diseases of p o s s i b l e importance are b r u c e l l o s i s , r a b i e s and l i s t e -r i o s i s . The low i n c i d e n c e of actinomycosis (Actinomyces b o v i s ) f i n s i x out of 462 s k u l l s examined, would suggest t h a t i t i s of no s i g n i f i c a n c e i n p o p u l a t i o n c o n t r o l . Reproductive 'JSafce The genetic p o t e n t i a l of the r e p r o d u c t i v e r a t e of muskoxen has not y e t been determined. Evidence presented i n t h i s t h e s i s , how-ever, has suggested t h a t the r a t e i n w i l d muskoxen i s r e l a t i v e l y low, and the p o s s i b i l i t y of a n u t r i t i o n a l b a s i s f o r t h a t r a t e has been explored. Such low p r o d u c t i v i t y may have a p o p u l a t i o n s u r v i v a l value f o r the muskox appears to be a l o n g l i v e d s p e c i e s , a twenty-two year o l d cow being recorded (Buckley, 1957), and a r a p i d i n -crease to a h i g h d e n s i t y p o p u l a t i o n i n a harsh environment would create i n c r e a s i n g competition f o r l i m i t e d resources, p a r t i c u l a r l y i n w i n t e r . I n other words, while food q u a l i t y or q u a n t i t y may be r e s t r i c t i n g the r e p r o d u c t i v e r a t e of muskoxen, such r e s t r i c t i o n would appear to be i n the i n t e r e s t of the s u r v i v a l of the species as a whole* Food Competition Competition f o r food may be i n t r a s p e c i f i c or i n t e r s p e c i f i c * I n the case of the species under study, both types may apply i n v a r y i n g degrees. - 169 For the present, the t o t a l areas o f w i n t e r and summer ranges are unknown, making i t i m p o s s i b l e to determine the t o t a l number of muskoxen the ranges w i l l support. The i n t e n s i t i e s of browsing and g r a z i n g on d i f f e r e n t ranges during summer and w i n t e r months a l s o need q u a n t i t a t i v e expression. For those reasons i t i s not yet p o s s i b l e to a s s e s s i n t r a s p e c i f i c food competition, i f i t e x i s t s , or to examine i n d e t a i l i n t e r s p e c i f i c food competition w i t h other herbivores such as c a r i b o u , lemmings or A r c t i c hare. Food Quantity and Q u a l i t y The q u a n t i t y arid q u a l i t y of forage produced on those muskox ranges examined i n the present study do not show c o n c l u s i v e l y t h a t those two f a c t o r s are c o n t r o l l i n g muskox p o p u l a t i o n growth. The Lake Hazen p l a n t production s t u d i e s do r e v e a l the sparseness of annual forag.e grown and i n d i c a t e q u i t e c l e a r l y t h a t other f a c t o r s being equal, muskox d e n s i t y there can never reach t h a t of the b e t t e r food-producing areas of the Thelon Game Sanctuary. Q u a l i t a -t i v e analyses of forage, however, has revealed t h a t the phosphorous content of p l a n t s on the Thelon ranges i s below the minimum recom-mended f o r domestic l i v e s t o c k and as such may be i n f l u e n c i n g r e -produ c t i o n of muskoxen. Fur t h e r i n v e s t i g a t i o n s of the above forage c h a r a c t e r i s t i c s and of the metabolic requirements of muskoxen are needed t o r e f i n e the conclusions drawn. From evidence obtained during the s t u d i e s to date ho s i n g l e f a c t o r can be s t a t e d c a t e g o r i c a l l y to be l i m i t i n g numbers of muskoxen. The data do suggest t h a t p a r a s i t i s m and disease are not l i m i t i n g p o p u l a t i o n growth. Wolf p r e d a t i o n may be a f a c t o r i n c a l f s u r v i v a l , p a r t i c u l a r l y on the A r c t i c i s l a n d s where a l t e r n a t i v e sources of prey - 170 are much rarer.and where lo n g periods of darkness may make defen-s i v e a c t i o n s o f muskoxen l e s s e f f e c t i v e i n r e p u l s i n g wolf a t t a c k s . In the Canadian A r c t i c c l i m a t e has not yet been demonstrated to be d i r e c t cause of death o f muskoxen. Climate i n f l u e n c e s muskox s u r v i v a l i n d i r e c t l y by l i m i t i n g the q u a n t i t y and q u a l i t y of food resources. Future s t u d i e s of muskoxen may show t h a t the u l t i m a t e l i m i t to t h e i r p o p u l a t i o n growth i n A r c t i c regions i s set by food through i t s i n f l u e n c e on r e p r o d u c t i o n , s u r v i v a l of young and the t o t a l number of the animals a given area w i l l support. D i s c u s s i o n The b i o l o g i c a l c h a r a c t e r i s t i c s of the species under study have been elaborated e a r l i e r i n t h i s t h e s i s . I t has been sug-gested t h a t the muskox i s adapted m o r p h o l o g i c a l l y , p h y s i o l o g i c a l l y and b e h a v i o u r a l l y t o the A r c t i c . The r e l a t i v e l y l a t e age of sexual m a t u r i t y i n cows (3+ years) and i n b u l l s ( 5 + years) reported f o r w i l d l i v i n g i n d i v i d u a l s , the low percentage of calves i n p o p u l a t i o n s t u d i e d (7 - 14 per c e n t ) , the production of calves b i e n n i a l l y , the low p r o d u c t i o n of food i n the high A r c t i c and only moderate amounts i n the Thelon Game Sanctuary and the b a r e l y adequate n u t r i -t i v e value of w i n t e r food species i n d i c a t e t h a t muskox populations i n northern regions w i l l not reach d e n s i t i e s which w i l l support i n t e n s i v e u t i l i z a t i o n . I n more southern regions of North America, b i g game popula-t i o n s are e x p l o i t e d f o r sport and meat. The deer (Odocoileus sp.) p a r t i c u l a r l y i s e x t e n s i v e l y u t i l i z e d across the continent where-ever i t occurs. U t i l i z a t i o n , at a r a t e unthinkable f o r muskoxen, i s permitted and i s b i o l o g i c a l l y d e s i r a b l e because of the high - 171 -p r o d u c t i v i t y of the species i n v o l v e d . Such p r o d u c t i v i t y or poten-* t i a l r a t e of i n c r e a s e , i s a f u n c t i o n , among other f a c t o r s , of t h e i r e a r l y age of sexual m a t u r i t y (7 months) and t h e i r annual f e r t i l i t y . R obinette (1956), f o r example, gives the p o t e n t i a l r a t e of i n c r e a s e of f o u r deer herds as being between 55 and 66 per cent. This i s f o u r times or more the p o t e n t i a l r a t e of i n c r e a s e of muskoxen, as given by L e s l i e (Appendix I I ) . So long as food c o n d i t i o n s are optimum i n w i n t e r and summer, deer populations can i n c r e a s e r a p i d l y (see Robinette, 1956, f o r summary). While somewhat l e s s p r o d u c t i v e , moose (Peterson, 1955) and e l k ( B a n f i e l d , 1949) populations s i m i l a r l y can reach d e n s i t i e s where extensive u t i l i z a t i o n i s d e s i r a b l e and b i o l o g i c a l l y necessary f o r the continued s u r v i v a l of the species and t h e i r food supply. I n p r o g r e s s i v e w i l d l i f e agencies the s e t t i n g of b i g game hunting r e g u l a t i o n s i s based on such f a c t o r s as the t o t a l s i z e of the p o p u l a t i o n , the s i z e of the c a l f crop, the s u r v i v a l to y e a r l i n g age of the previous year's c a l v e s , the r a t e of p o p u l a t i o n i n c r e a s e and the r e l a t i o n s h i p between t o t a l p o p u l a t i o n s i z e and t h e . a b i l i t y of ranges to support t h a t p o p u l a t i o n . These data are necessary i f the game populations are to be harvested optimumly. Sc o t t (1954) has discussed p o p u l a t i o n growth of game species and the management which should be d i r e c t e d to r e a l i z i n g optimum y i e l d s . Any u t i l i z a t i o n of muskoxen a l s o must be based on the species b i o l o g i c a l c h a r a c t e r i s t i c s as discussed above. I t i s apparent from the i n f o r m a t i o n obtained i n the present study t h a t muskox u t i l i z a t i o n w i l l be l i m i t e d , even i n the areas most favourable f o r the species p o p u l a t i o n growth. The production and n u t r i t i v e value of food on - 172 muskox ranges s e t o u t s i d e l i m i t s on the numbers of animals able t o e x i s t t h e r e . Food i s so scarce i n high A r c t i c regions t h a t such numbers w i l l always be low unless favourable c l i m a t i c changes occur. W i t h i n t h a t l i m i t a t i o n the low re p r o d u c t i v e r a t e and feeding h a b i t s of the species operate which f u r t h e r reduces the number of musk-oxen which w i l l be found i n a given area. While s u r v i v a l of calves to y e a r l i n g age approximate t h a t of other b i g game s p e c i e s , and although l o n g e v i t y appears to exceed t h a t of some other w i l d - l i v i n g ungulates such as deer, moose, c a r i b o u , elk and mountain sheep, those f a c t o r s do not compensate muskoxen f o r t h e i r comparatively l a t e age o f sexual m a t u r i t y or t h e i r f a i l u r e to ca l v e every year. Cole (1954) has r e c e n t l y emphasized the adverse e f f e c t of delayed m a t u r i t y and of the number of young per b i r t h on the i n t r i n s i c r a t e of n a t u r a l i n c r e a s e . I n summary, the b i o l o g i c a l c h a r a c t e r i s t i c s of muskoxen and of the environment which supports them are such t h a t only the most l i m i t e d u t i l i z a t i o n of the species can be considered. Recommendations f o r U t i l i z a t i o n . From 1917to 1959, muskoxen had been completely protected i n Canada, even the Eskimos and Indians having been fo r b i d d e n t o hunt them, because o f the r e a l danger of the species extermination, par-t i c u l a r l y on the A r c t i c mainland. The d i s t r i b u t i o n a l data i n t h i s thesis,however, i n d i c a t e a general i n c r e a s e i n numbers of muskoxen and t h e i r reoccupying of former range, depleted e a r l i e r by ex-p l o r e r s , whalers and robe hunters. On the mainland the data suggest areas of r e l a t i v e abundance i n the Bathurst I n l e t r e g i o n , where about 450 are thought to e x i s t , and i n the Thelon Game Sanctuary, where some 350 l i v e . 173 -On the A r c t i c i s l a n d s numerous i n d i v i d u a l s appear to be found o n l y on Ellesmere, where two thousand are estimated to be, a l -though Axel Heiberg and M e l v i l l e I s l a n d s may have two hundred or more each. Any c o n s i d e r a t i o n given to r e s t r i c t e d u t i l i z a t i o n of muskoxen must be confined, t h e r e f o r e to the Bathurst I n l e t r e g i o n and the Thelon Game Sanctuary on the A r c t i c mainland and to Ellesmere Island, For reasons explained l a t e r , however, Bathurst I n l e t i s not a d e s i r a b l e p l a c e to u t i l i z e muskoxen. The muskox i s a polygamous s p e c i e s . Those b u l l s unsuccesful i n o b t a i n i n g a herd, or which f o r some other reason do not par-t i c i p a t e i n the r u t , are u s u a l l y found l e a d i n g a s o l i t a r y e x i s t -ence i n summer. I n w i n t e r such b u l l s tend to form herds of t h e i r own or j o i n herds of mixed sexes and ages. At any r a t e a b i o l o -g i c a l s urplus of b u l l s e x i s t s i n areas where t o t a l numbers of the animals are r e l a t i v e l y h i g h . I n areas of few muskoxen s o l i t a r y b u l l s may p l a y an important p a r t by t h e i r wanderings i n the r e -oocupation: of new or former ranges. The s o l i t a r y b u l l s i n the above three regions of abundance could be eonsidered f o r l i m i t e d and t i g h t l y c o n t r o l l e d u t i l i z a t i o n . T h e i r numbers are not such as to provide s i g n i f i c a n t amounts of food f o r Eskimo use but they are s u f f i c i e n t l y abundant to provide m a t e r i a l f o r s c i e n t i f i c purposes of museums, zoos and u n i v e r s i t i e s . I n recent years considerable i n t e r e s t has been shown by the p u b l i c i n the p o s s i b i l i t i e s of domesticating the muskox f o r animal husbandry i n s u b a r c t i c and A r c t i c regions of Canada. The Canadian Government granted permission to the I n s t i t u t e of Northern 174 * A g r i c u l t u r a l Research of Vermont, U.S.A., to capture e i g h t muskox calv e s f o r experimental domestication purposes. Seven calves were captured, f o u r i n 1954 and three i n 1955, and three subsequently d i e d . The two cows gave b i r t h i n 1958 to two c a l v e s , one of which was s t i l l b o r n and the second of which died a t s i x weeks of age. The s t i l l b o r n c a l f was produced by a three year o l d cow. I t was the o p i n i o n of the v e t e r i n a r i a n a t t e n d i n g the b i r t h t h a t c a l f was too l a r g e f o r passage. That i s a d i s t i n c t p o s s i b i l i t y f o r cows do not achieve f u l l m a t u r i t y u n t i l a t l e a s t f o u r years of age. In 1959 two c a l v e s were born, but one d i e d a t three months of age. The two b u l l s a r e l a r g e animals, and even though not y e t f u l l y grown, are l a r g e r than t h e i r w i l d counterparts, a r e s u l t of a supplemented d i e t . Before muskox husbandry i s t r i e d i n northern r e g i o n s , the social problem of herding by Eskimos must be condidered. The f a i l u r e of those people to take to r e i n d e e r herding a t A k l a v i k would suggest t h a t at present any attempts to i n t e r e s t Eskimos i n muskox r a i s i n g must be f r a u g h t w i t h the p o s s i b i l i t y of s i m i l a r f a i l u r e . A f a c t o r which must be considered i n c a p t u r i n g or k i l l i n g animals f o r s c i e n t i f i c purposes i s the e f f e c t such a c t i o n s would have on l o c a l Eskimos who have not been permitted t o hunt muskoxen by law. This law has been shown r e c e n t l y to be i n v a l i d c o n s t i t u -t i o n a l l y , but i t i s hoped that i n a r e l a t i v e l y short p e r i o d of time steps w i l l be taken to c o r r e c t the s i t u a t i o n . The f o l l o w i n g d i s -c u s s i o n i s p r e d i c a t e d on the assumption t h a t no muskox hunting w i l l be allowed. As s t a t e d e a r l i e r there are not enough animals i n any one area to withstand more than a token u t i l i z a t i o n and to be s i g n i f i c a n t i n terms of Eskimo use a r e l a t i v e l y l a r g e r number would - 175 have to be k i l l e d . I n a d d i t i o n there i s the very r e a l problem of enforcement, should Eskimos be allowed to take a few from a given a r e a . I l l e g a l k i l l i n g i s d i f f i c u l t enough to s t o p even w i t h a t o t a l ban on hunting, but once a hunter has an exeuse to possess muskox hides or meat the enforcement o f an area quota would be-come v i r t u a l l y i m p o s s i b l e i n a r e g i o n as remote as the A r c t i c and w i t h people who have l i t t l e or no concept of c o n s e r v a t i o n . By the same token i t i s d o u b t f u l i f many Eskimos would understand the pur-pose of s c i e n t i f i c c o l l e c t i o n g and they n a t u r a l l y may resent not being able to use an animal t h a t an " o u t s i d e r " may. Care must be exercised when g r a n t i n g permission to s c i e n t i f i c i n s t i t u t i o n s or to i n d i v i d u a l s f o r the capture or k i l l i n g of musk-oxen t h a t the areas s e l e c t e d f o r the removal of the animals are not ones frequented by Eskimos. Areas of some numbers of muskoxen and Eskimos, such as Bathurst I n l e t , should not be open to c o l l e c t i n g u n t i l such times as muskox numbers are great enough to permit Eskimo hunting a l s o . The u t i l i z a t i o n of muskoxen i n any area and i n any one year must be o n l y i n the l i g h t of the l a t e s t b i o l o g i c a l i n f o r m a t i o n of the p o p u l a t i o n being considered f o r e x p l o i t a t i o n . I n a d d i t i o n , c e r t a i n l i n e s of fundamental rese a r c h , elaborated elsewhere i n t h i s t h e s i s , must be pursued before an adequate under-standing of muskox b i o l o g y and range requirements i s achieved. Such b a s i c and important b i o l o g i c a l c h a r a c t e r i s t i c s as r e p r o d u c t i o n , metabolism and c o l d a d a p t a t i o n should be known thoroughly f o r a sound b a s i s upon which to undertake management of the species and f o r any f u t u r e domestication programs i n northern areas. * 176 The f o l l o w i n g recommendations f o r u t i l i z a t i o n , have been ap-proved by the Department of Northern A f f a i r s . X . Permission be granted to a c c r e d i t e d n a t i o n a l , p r o v i n c i a l or p r i v a t e o r g a n i z a t i o n s , Canadian or American, t o e i t h e r k i l l o r capture b u l l muskoxen upon request. I n i t i a l l y i t would be a d v i s a b l e to l i m i t each a p p l i c a n t to not more than two animals. The t o t a l number taken i n one area i n any one year should be subject t o review i n the l i g h t of the l a t e s t b i o l o -g i c a l i n f o r m a t i o n a v a i l a b l e . 2. For the present, a p p l i c a t i o n s f o r i n d i v i d u a l s o r i n s t i t u t i o n s f o r muskox calves f o r d i s p l a y or f o r domestication experiments should be considered o n l y on the b a s i s of a research program d i r e c t e d towards the s t u d y of the b a s i c b i o l o g y of the animal, i . e . f a c t o r s i n f l u e n c i n g or c o n t r o l l i n g r e p r o d u c t i o n , meta-bo l i s m and c o l d a d a p t a t i o n . 3. The hunting of muskoxen by Eskimos or by anyone e l s e f o r sport or food should not be permitted u n t i l the populations o f the animals have incr e a s e d m a t e r i a l l y . Future Research Problems The present study has done l i t t l e more than to o u t l i n e the nature of problems r e q u i r i n g f u r t h e r i n v e s t i g a t i o n . Such problems can be d i v i d e d i n t o two types, f i e l d and l a b o r a t o r y . F i e l d s t u d i e s should be on a c o n t i n u i n g b a s i s and should seek to keep abreast of the dynamics of muskox populations throughout t h e i r range on the mainland and the i s l a n d s . Laboratory s t u d i e s should attempt to explore f a c t o r s i n f l u e n c i n g r e p r o d u c t i o n , metabolism and c o l d a d a p t a t i o n . - 177 -S p e c i f i c a l l y f i e l d s t u d i e s , which f o r the most part need not be lengthy, should be d i r e c t e d t o g e t t i n g data on c a l f crops, year-l i n g s u r v i v a l , age and sex c l a s s e s i n immature animals, a d u l t sex r a t i o s ; m o r t a l i t y f a c t o r s such as p r e d a t i o n by wolves; g r a z i n g i n -t e n s i t y of herds; and i n f l u e n c e s of c l i m a t e on range p r o d u c t i v i t y , i n c l u d i n g the assessment of the e f f e c t s of seasonal changes on the n u t r i t i v e value of food p l a n t s . The l a s t two o b j e c t i v e s probably can be s t u d i e d only by a s e r i e s of lengthy o b s e r v a t i o n s . S p e c i f i c l a b o r a t o r y researches, w i t h animals i n c a p t i v i t y , should be d i r e c t e d towards the determination of the i n f l u e n c e of l i g h t on o e s t r u s ; the e f f e c t s of v a r y i n g planes of n u t r i t i o n on the growth and age of sexual m a t u r i t y of b u l l s and cows and on t h e i r f e r t i l i t y and f e c u n d i t y once mature; the way i n which the animals metabolize t h e i r n a t i v e foods and p a r t i c u l a r l y how they u t i l i z e and synthesize p r o t e i n s ; the methods, both by i n s u l a t i o n and metabolism, by which the animals can withstand the r i g o r s of w i n t e r weather and how newborn calves can cope w i t h a winter en-vironment. The l a b o r a t o r y problems can best be c a r r i e d out at an A r c t i c r esearch s t a t i o n , equipped f o r such work, f o r the necessary c l i m a t i c c o n d i t i o n s and food s u p p l i e s would be a t hand. Should such a s t a t i o n not be a v a i l a b l e i n the near f u t u r e then the s t u d i e s should be c a r r i e d out at a u n i v e r s i t y . - 178 * A Study i n V a r i a t i o n of the S k u l l s and Body Measurements of the Subspecies of Muskoxen. A p r e l i m i n a r y examination of the l i t e r a t u r e of muskox (Ovibos  moschatus subsp.) taxonomy i n d i c a t e d that t he bases f o r the creation of subspecies of muskoxen are somewhat tenuous. P a r t i c u l a r l y questionable i s A l l e n ' s (1913) s e p a r a t i o n o f Ovibos moschatus  moschatus (Zimmerman) from Ovibos m. niphoecus E l l i o t , when an e r r o r i s co r r e c t e d i n the mean b a s a l lengths he gave of s k u l l s of two forms. Some measurements of mine from s k u l l m a t e r i a l c o l l e c t e d a t Lake Hazen, Northern Ellesmere I s l a n d , i n d i c a t e d t h a t the t h i r d d e s cribed subspecies of muskoxen, Ovibos m. wardi Lydekker, may e x i b i t s i z e v a r i a t i o n as great as e x i s t e d among the three subspecies. For those reasons a study of v a r i a t i o n of s k u l l measurements of the three subspecies was undertaken to t e s t A l l e n ' s c o n c l u s i o n s . This s e c t i o n , which r e p o r t s the r e s u l t s of tha t study, i s based l a r g e l y on s k u l l measurements and c e r t a i n t e e t h c h a r a c t e r i s t i c s . A b r i e f examination o f body measurements a l s o i s dis c u s s e d . A d e f i n i t i v e study of muskox subspecies w i l l r e q u i r e examination of s k i n s of type and topotype m a t e r i a l , which I was unable to do. M a t e r i a l Examined The 230 a d u l t b u l l s k u l l s examined during the course of t h i s study i n c l u d e one i n the Chicago Na t u r a l H i s t o r y Museum, 32 i n the American Museum of N a t u r a l H i s t o r y , 14 i n the United S t a t e s National Museum, 24 i n the N a t i o n a l Museum of Canada, 11 measured by Dr. Ian Met. Cowan i n the Copenhagen Museum,one i n the museum of the Department of Zoology of the U n i v e r s i t y of B r i t i s h Columbia and 147 which were measured i n the f i e l d during an e c o l o g i c a l study - 179 -o f muskoxen at Lake Hazen, Ellesmere I s l a n d . Only seven measure-ments could be taken of the Lake Hazen m a t e r i a l as most of the s k u l l s had been damaged to v a r y i n g degrees by weather and predators. Table XXXIVbelow gives the o r i g i n of the s k u l l m a t e r i a l . Table XXXIV. Number and o r i g i n of a d u l t b u l l s k u l l m a t e r i a l , by subspecies. O.m. moschatus O.m. niphoecus O.m. wardi O r i g i n Number O r i g i n Number O r i g i n Number Bathurst I n l e t 2 Wager Bay 1 P r i n c e Wales 8 i s l a n d Great Slave W. Hudson Lake 1 Bay 4 C o r n w a l l i s I s l a n d 2 Barren-grounds C h e s t e r f i e l d P r i n c e P a t r i c k east of Mac- I n l e t I s l a n d k e n z i e R i v e r 1 1 3 Aylmer Lake 1 Devon I s l a n d 5 F o r t Good Hope 1 M e l v i l l e I s l a n d 4 Barr en-grounds 1 N. Ellesmere 18 I s l a n d F a i r f o r d , Manitoba 1 W. Greenland 3-2 Thelon Game E. Greenland 12 Sanctuary 5 Lake Hazen, Ellesmere I s l a n d 147 T o t a l 13 6 211 I n a d d i t i o n t o the eight P r i n c e of Wales I s l a n d specimens, s k u l l s of two n e a r l y mature b u l l s and the p a l a t e s and upper t o o t h -rows of 1$ a d u l t b u l l s were a v a i l a b l e from th a t i s l a n d f o r study. The raw measurement data are i n the f i l e s of the Canadian W i l d l i f e S e r v i c e , Ottawa. - 180 « H i s t o r y of the Systematics of Recent Muskoxen A l l e n (op. c i t . ) has given a good review of the i n t r o d u c t i o n of the muskox i n t o systematic l i t e r a t u r e and only a summary w i l l be given here. A French f u r t r a d e r , N i c o l a s Jeremie, i s c r e d i t e d w i t h the f i r s t p u b l ished account of the s p e c i e s , which appeared i n a c o l l e c t i o n of voyages published i n Amsterdam i n 1720 by Jean-F r e d e r i c Bernard (1720). Subsequent ex p l o r e r s of the Hudson Bay r e g i o n provided f u r t h e r d e t a i l s of the animal but i t was Hearne (1795) who made the f i r s t major c o n t r i b u t i o n about i t s h a b i t s and d i s t r i b u t i o n , based upon h i s observations w h i l e c r o s s i n g the tundra from the C h u r c h i l l R i v e r t o the Coppermine R i v e r . Zimmerman (1780) introduced the muskox i n t o systematic z o o l o -gy under the name Bos moschatus. His i n f o r m a t i o n was based on the d e s c r i p t i o n of Jeremie, and A l l e n , t h e r e f o r e , has placed the type l o c a l i t y of the subspecies (Ovibos m. moschatus) i n the region a d j o i n i n g Hudson Bay, between the Seal and C h u r c h i l l R i v e r s . D e B l a i n v i l l e (1816) removed the muskox from the genus Bos and created f o r i t the monotypic genus,- Ovibos, a name designed to i n -d i c a t e the animals supposed a f f i n i t i e s w i t h both Ovis and Bos. A l l e n discussed i n d e t a i l the r e l a t i o n s h i p of Ovibos to other genera and concluded t h a t i t belonged to the subfamily Bovinae, w i t h the genusBison as i t s nearest r e l a t i v e among e x i s t i n g mammals. Simpson (1945) placed Ovibos i n the t r i b e O v i b o v i n i , of the sub-f a m i l y Caprinae, and considered the t a k i n (Budorcas) the nearest l i v i n g r e l a t i v e of the muskox. Further l i g h t on muskox r e l a t i o n -s h i p has been given by Moody (1958), who on the b a s i s of s e r o l o -- 181 -g i c a l s t u d i e s concluded t h a t muskoxen are r e l a t e d to sheep and goats and markedly d i s s i m i l a r to domestic c a t t l e and b i s o n , thus supporting.Simpson's i n t e r p r e t a t i o n . A d d i t i o n a l evidence of r e l a t i o n s h i p w i t h sheep was obtained d u r i n g the present study when i t was found (Hopkins and Chisolm, 1957) t h a t muskox fat. contains a f a t t y a c i d reported p r e v i o u s l y only from sheep. Present S u b s p e c i f i c D e s c r i p t i o n A l l e n (op. c i t . ) has recognized three subspecies. They are 0. moschatus moschatus (Zimmerman), the barren-ground muskox, 0. m. niphoecus E l l i o t , the Hudson Bay muskox f i r s t decribed i n 1905 and 0. m . wardi Lydekker, the Greenland muskox, named i n 1900* To A l l e n (op. c i t . ) must go the c r e d i t a l s o f o r r e s o l v i n g much of the confusion of the s t a t u s of the subspecies, p a r t i c u l a r l y f o r r e f u t i n g the claims of Kowarzik (1910), who d i v i d e d the muskox i n t o two groups f o r which he gave each generic s t a t u s and i n which he recognized f i v e s p e c i e s * The d e s c r i p t i o n s of the l i v i n g forms, a c c o r d i n g to A l l e n (op. c i t . ) , are as f o l l o w s : "No coronal nor f a c i a l white areas i n a d u l t s ; horns dark brown, very broad a t base i n p r o p o r t i o n to t h e i r l e n g t h ; toothrow r e l a -t i v e l y short (max:. ., toothrow 132), b a s a l l e n g t h of s k u l l i n o l d males, 466 mm. O.m. moschatus. U s u a l l y no coronal nor f a c i a l white areas i n a d u l t males but t r a c e s of them ( o f t e n w e l l developed) i n young males and females; horns more slender and longer i n p r o p o r t i o n to t h e i r b a s a l breadth and g e n e r a l l y l i g h t - c o l o u r e d ; toothrow r e l a t i v e l y longer (max. series i n males 130 mm.); b a s a l l e n g t h of s k u l l i n o l d males, 442 mm....... O.m. niphoecus. - 182 -Conspicuous areas of white between and behind the horns, and fac e and sides of the head sometimes suffu s e d w i t h white to a grea t e r or l e s s extent i n o l d males, i n which much of the o r i g i n a l white area i s o b l i t e r a t e d by the development of the horn bases; horns longer and slender i n p r o p o r t i o n to t h e i r b a s a l breadth, very l i g h t creamy white; tooth row r e l a t i v e l y longer then i n moschatus (max. s e r i e s i n males 140 mm.); b a s a l l e n g t h of s k u l l s i n o l d males, 442mm. O.m. wardi." There have been two papers published subsequent to A l l e n ' s which t r e a t muskox taxonomy r a t h e r b r i e f l y . Degerbj^l (1935) argued f o r separate s u b s p e c i f i c s t a t u s of the east Greenland animals, c l a i m i n g t h a t the muskoxen of west Greenland and of the A r c t i c i s l a n d s of Canada were i n t e r g r a d e s between O.m. wardi of east Green-land and O.m. moschatus of c o n t i n e n t a l Canada. He based h i s argue-raent c h i e f l y on the shape and breadth of the horn base. Manning and Macpherson (1958), however, showed that the mean of the measure-ments of the breath of the east Greenland specimens given by Degerb^l d i d not d i f f e r s i g n i f i c a n t l y from the mean of A l l e n ' s measurements of northern Ellesmere I s l a n d specimens, thus negating Degerb^l's c l a i m . Manning and Macpherson's (op. c i t . ) paper d e a l t c h i e f l y w i t h m a t e r i a l obtained on Banks I s l a n d i n the western A r c t i c , which they assigned to O.m. wardi. I n d i v i d u a l and secondary sexual v a r i a t i o n s i n the genus have been discussed a t length by A l l e n and w i l l not form a part of t h i s paper. - 183 -D e f i n i t i o n of Measurements To assess v a r i a t i o n i n muskox s k u l l s , the f o l l o w i n g measure-ments were taken w i t h the use of a l a r g e c a l i p e r , a v e r n i e r c a l i p e r , a 50 cm. s t e e l r u l e or a 2\ metre s t e e l tape; T o t a l l e n g t h : g r e a t e s t d i s t a n c e between the p o s t e r i o r face of the r i g h t o c c i p i t a l condyle and the t i p of the r i g h t p r e m a x i l l a . B a s i l a r l e n g t h : g r e a t e s t d i s t a n c e between i n f e r i o r l i p of the foramen magnum and the t i p of the p r e m a x i l l a e . Least o r b i t a l width: l e a s t width i n a s t r a i g h t l i n e taken w i t h c a l i p e r s r e s t i n g i n notch on o r b i t a l r i m at lower edge of lachrymal bone. Greatest o r b i t a l width: g r e a t e s t width i n a s t r a i g h t l i n e taken w i t h c a l i p e r s r e s t i n g a g a i n s t outer edge of o r b i t . P o s t o r b i t a l width: l e a s t width of s k u l l between o r b i t s and base of horns. Nasal-lambdoidal c r e s t l e n g t h : g r e a t e s t d i s t a n c e i n a s t r a i g h t l i n e between p o s t e r i o r f a c e of lambdoidal c r e s t to a n t e r i o r t i p of n a s a l . Horns spread: d i s t a n c e between t i p s of horns, i n a s t r a i g h t l i n e . Mastoid width: g r e a t e s t d i s t a n c e across o c c i p u t between e x t e r n a l ( l a t e r a l ) surfaces of the mastoid processes of the squamosal a t the v e n t r a l end of the lambdoidal c r e s t . Nasal l e n g t h : g r e a t e s t d i s t a n c e from a n t e r i o r margin to p o s t e r i o r margin of r i g h t n a s a l unless t h i s i s broken or malformed. Nasal width: g r e a t e s t combined width of n a s a l s . - 184 * Least d i s t a n c e between s u p r a o r b i t a l foramen: l e a s t d i s t a n c e i n a s t r a i g h t l i n e taken w i t h c a l i p e r s r e s t i n g i n foramina. P r e m a x i l l a e width: g r e a t e s t width across p r e m a x i l l a e opposite a n t e r i o r end of a n t e r i o r p a l a t i n e foramina. P a l a t a l breadth a t M^: l e a s t d i s t a n c e across p a l a t e w i t h c a l i p e r s r e s t i n g on the i n s i d e edge of the a l v e o l u s of the p o s t e r i o r cusp of M^. P a l a t a l breadth a t PlYr: l e a s t d i s t a n c e across p a l a t e between a l v e o l i of f i r s t premolar. P o s t - p a l a t a l width: l e a s t width of the p a l a t i n e s p o s t e r i o r to t h i r d upper molars. B a s i o c c i p i t a l width: l e a s t width of t h i s element between foramina o v a l e . Post d e n t a l l e n g t h : l e a s t d i s t a n c e between a l v e o l i of t h i r d upper molar and a n t e r i o r margin of p a r o c c i p i t a l process on same s i d e . Zygomatic width: g r e a t e s t d i s t a n c e of zygomatic arches across jugo-squamosal suture. P a l a t a l l e n g t h : l e a s t d i s t a n c e from p o s t e r i o r margin of p a l a t e to a n t e r i o r edge of p r e m a x i l l a e on m i d l i n e . A l v e o l a r l e n g t h : g r e a t e s t a l v e o l a r l e n g t h of combined upper r i g h t molars and premolars, P r e a l v e o l a r l e n g t h : l e a s t d i s t a n c e between a l v e o l u s of second upper premolar ( f i r s t t o o t h of upper s e r i e s ) and t i p of the r i g h t p r e m a x i l l a . - 185 -Analyses of M a t e r i a l A l l e n ' s d e s c r i p t i o n s of the l i v i n g forms given on P.180 of h i s monograph c o n t a i n a t l e a s t three E r r o r s , The mean maxillary-t o o t h row l e n g t h of h i s O.m. moschatus s e r i e s , according t o the raw data i n h i s t a b l e s i s 134 mm., not 132 and the mean b a s a l l e n g t h of the same subspecies i s 443 mm., not 466. The mean m a x i l l a r y t o o t h row l e n g t h of O.m. niphoecus i s 131 mm., and not 130. P o s s i b l y because of d i f f e r e n c e s i n technique, the measure-ments obtained i n the present study d i f f e r e d f o r the same s k u l l s from A l l e n ' s measurements. I n some cases, a l s o , s k u l l s had d r i e d out i n the 45 year p e r i o d e x i s t i n g between the st u d i e s and s k u l l bones had separated, i n c r e a s i n g c e r t a i n measurements. I n other cases, the bones probably shrank w i t h d e s s i c a t i o n , reducing measurements. As f a r as p o s s i b l e allowances were made f o r such biases when t a k i n g these measurements. I t i s not p o s s i b l e , how-ever, to i n c l u d e A l l e n ' s data w i t h t h a t of the present study because of the above d i s c r e p a n c i e s . The extent to whieh the age a t death of the specimens con-t r i b u t e d to the v a r i a b i l i t y of the measurements has not been worked out, p r i n c i p a l l y because of the l a c k of a r e l i a b l e method w i t h which to determine the ages of a d u l t muskoxen, but a l s o because the smallness of the samples from the two named subspecies from the A r c t i c mainland made i t necessary to group the data. I t i s u n l i k e l y t h a t changes i n a d u l t muskoxen w i t h age would exceed the v a r i a b i l i t y among i n d i v i d u a l s of a given age i n a p o p u l a t i o n . Once the experimental ageing of the Lake Hazen too t h samples has - 186 -been completed, i t may be p o s s i b l e , among other t h i n g s , to deter-mine changes i n measurements w i t h age. I t i s of some concern t h a t the s k u l l s of only s i x a d u l t b u l l s of the Hudson Bay muskox and of 13 of the Barren-Ground muskox were a v a i l a b l e f o r measurement (Table XXXJV)..It i s b e l i e v e d t h a t the s t a t i s t i c a l procedures f o l l o w e d i n the analyses permitted some con-c l u s i o n s t o be drawn about the s k u l l s , n e v e r t h e l e s s . The data were d i v i d e d i n t o seven groups, except f o r those measurements which were mis s i n g i n the P r i n c e of Wales I s l a n d and the Lake Hazen p o p u l a t i o n s . The seven groups were as f o l l o w s : 0. moschatus moschatus  O.m..niphoecus O.m. wardi (1) - P r i n c e of Wales I s l a n d . P.m. wardi (2) - P r i n c e P a t r i c k , M e l v i l l e , C o r n w a l l i s , Devon I s l a n d . O.m. wardi (3) - Northern Ellesmere I s l a n d . O.m. wardi (4) - East and west (north) Greenland. O.m. wardi (5) - Lake Hazen. Q u a n t i t i e s of s k u l l s from each of the i s l a n d s of group two were i n s u f f i c i e n t f o r analyses so were grouped.T Tests showed no d i f f e r e n c e s between the east and west Greenland m a t e r i a l (Table XXXV"_)/ so those two set s of data were grouped a l s o . The Lake Hazen m a t e r i a l was kept separate from the other Ellesmere I s l a n d date beeause the 147 specimens, having been found w i t h i n a t e n m i l e r a d i u s of the shores of the l a k e , represented a s i n g l e p o p u l a t i o n i n space, though not i n time, and as s t a t e d e a r l i e r , were l a r g e r than specimens from other areas on Ellesmere I s l a n d . 187 -Table XXXV.. Tests of Significances of the Differences i n Measurements between East and West (north), Greenland Adult Bull Skulls. West Greenland East Greenland " t " test Measurement M X S 2 N X S2 t P.05 total length 12 467.7 428.16 12 464.8 238.5 .37 2.201 basal length 12 435.17 418.3 12 430.6 248.4 .585 2.201 alveolar length 12 139.9 43.52 12 138.7 28.77 .468 2.201 mastoid width 11 168.7 123.37 12 161.25 135.04 1*50 2.214 palatal width 25.46 at PM2 12 55.1 12 56.8 45.30 .67 2.201 palatal width 79.6 at M? 12 31.91 12 83.50 18.38 1.84 . 2.201 Standard s t a t i s t i c a l methods were used to obtain means, standard deviations, coefficients of vari a b i l i t y , and their standard errors of the measurements. The results of the analyses of each measurement were then tabulated by population, and graphed according to the method of Hubbs and Hubbs (1953). The tables and graphs are in Appendix I. The tabulated data revealed marked differences i n means of most measurements and revealed particularly the variation i n size i n adult animals among the various O.m. wardi populations. Because size differences may reflect responses to different environmental conditions and not be genotypic i n nature, the a r t i f i c i a l l y selected population samples of muskoxen were treated by analyses of cova-riance, to test the relationship between the length of the skull and i t s width'. Four such analyses were possible using six of the seven groups of data. There was insufficient material from Prince of Wales Island for analysis. The Lake Hazen material was included as a M 188 — separate group because of the s i g n i f i c a n t l y g r e a t e r measurements of t o t a l and basa l l e n g t h s , mastoid width and p a l a t a l width a t the second premolar, than any other muskox p o p u l a t i o n sample (see graphs). The f o u r r e g r e s s i o n s were as f o l l o w s : mastoid width on basa l l e n g t h g r e a t e s t zygomatic width on b a s a l l e n g t h width of p a l a t e a t PM 2 on b a s a l l e n g t h If f t I t » #[3 f t I t t t : Those r e g r e s s i o n s were thus able t o t e s t the r e l a t i o n s h i p of s k u l l l e n g t h t o i t s width both p o s t e r i o r l y and, i n p a r t , a n t e r i o r l y . Two a d d i t i o n a l regressions were c a l c u l a t e d , t h i s time w i t h a l l seven groups. The f i r s t , p a l a t a l width a t PM*" on a l v e o l a r l e n g t h , was undertaken.to see what r e l a t i o n s h i p , i f any, e x i s t e d between the l e n g t h of the upper tooth row and the width of the p a l a t e . The second r e g r e s s i o n , a l v e o l a r l e n g t h a g a i n s t g r e a t e s t zygomatic width was then undertaken to determine i f the s i g n i f i c a n t l y greater a l -v e o l a r l e n g t h of the high A r c t i c populations was a f u n c t i o n of s k u l l width, and a l s o beeause of the very i n t e r e s t i n g negative r e g r e s s i o n c o e f f i c i e n t s obtained i n the f i r s t . The covariance t a b l e s , and t a b l e s of the adjusted means and t h e i r standard e r r o r s are given i n Appendix I, A l v e o l a r l e n g t h i s a measurement f r e q u e n t l y used i n taxonomic treatments of mammals and A l l e n (op, c i t , ) employed the measurement as one of s e v e r a l c r i t e r i a f o r t h e se p a r a t i o n of the three e x i s t i n g subspecies of muskoxen. The " t n t e s t was t h e r e f o r e a p p l i e d to t e s t the s i g n i f i c a n c e of the d i f f e r e n c e s i n the mean a l v e o l a r lengths of the three subspecies, i n the f o l l o w i n g manner; s i g n i f i c a n c e of d i f -189' -ference between O.m. moschatus and P.m. niphoecus. between the combined measurements of those two populations and the s e r i e s from O.m. wardi c o l l e c t e d on P r i n c e o f Wales I s l a n d , between the P r i n c e of Wales I s l a n d s e r i e s and the s e r i e s #2 o f O.m. w a r d i f and between the combined measurements of the two mainland s e r i e s and the r e s t of the O.m. wardi s e r i e s , the P r i n c e of Wales I s l a n d s e r i e s excepted. The method employed was t h a t given by Edwards (1956) f o r determining the s i g n i f i c a n c e o f the d i f f e r e n c e between two means when the variances d i f f e r s i g n i f i c a n t l y . R e s u l t s Seven measurements were obtained from the Lake Hazen m a t e r i a l , t o t a l l e n g t h , b a s a l l e n g t h , g r e a t e s t zygomatic width, mastoid width, width of p a l a t e a t the second premolar, width of p a l a t e a t the t h i r d molar and a l v e o l a r l e n g t h . The mean o f each of the measurements except the t h i r d , s i x t h and seventh, were s i g n i f i c a n t l y g r e a t e r than the mean of the same measurement of the remaining O.m. wardi p o p u l a t i o n s . The Lake Hazen animals, i n other words, had longer and wider s k u l l s , but the mean upper tooth row l e n g t h was s t a t i s t i c a l l y the same as those of the remaining f o u r O.m.  wardi populations examined. The s e r i e s c l o s e s t i n s i z e to the Lake Hazen group, except f o r a l v e o l a r l e n g t h , was O.m. moschatus the western and c e n t r a l c o n t i n e n t a l form (see graphs and ta b l e s i n Appendix I ) . Furthermore, the means of the above measurements except f o r t h a t of a l v e o l a r l e n g t h , of P.m. moschatus and O.m.  niphoecus f e l l w i t h i n one standard d e v i a t i o n from the mean o f the corresponding measurements i n the O.m. wardi s e r i e s . - 190 -The l e s s e r v a r i a b i l i t y of a l v e o l a r l e n g t h among P.m. wardi p o p u l a t i o n samples i s revealed i n Table LVTII i n Appendix I . The s i g n i f i c a n c e s of the d i f f e r e n c e s i n a l v e o l a r lengths were t e s t e d by " t " t e s t s , the r e s u l t s of which are given i n Table XXXVI below. Table XXXVI Tests of S i g n i f i c a n c e of the D i f f e r e n c e s i n A l v e o l a r Lengths i n three Subspecies. P o p u l a t i o n N T P.P5 P.m. moschatus 13 .698 P.m. niphoecus 6 3.415 P.m.m.+P.m.n. 19 .336 P.m. wardi (Prince 2.P84 of Wales Island) 23 P.m. wardi ( P r i n c e of Wales Island) 23 P.m. wardi ( s e r i e s #2) 14 3.P88* 2.P99 P.m.m.+P.m.n. 19 P.m. wardi (except 7.P85* 2.P78 Pri n c e of Wales I s l a n d 2P3 * s i g n i f i c a n t The analyses i n d i c a t e d t h a t t h e r e was no s t a t i s t i c a l l y s i g -n i f i c a n t d i f f e r e n c e i n the means between P.m. moschatus and P.m.  niphoecus. Because of t h i s f a c t , the raw data from the two sub-species were combined f o r subsequent analyses of a l v e o l a r l e n g t h s . Those analyses showed there was no s i g n i f i c a n t d i f f e r e n c e between the combined subspecies and the P r i n c e of Wales I s l a n d form. A s i g n i f i c a n t d i f f e r e n c e does e x i s t , however, between the r e s t of the P.m. wardi s e r i e s and the combined mainland s e r i e s , the former being l o n g e r . A s i g n i f i c a n c e d i f f e r e n c e e x i s t s a l s o between the P r i n c e of Wales I s l a n d s k u l l s and the r e s t of the P.m. wardi s p e c i -mens. - 191 When the c o e f f i c i e n t o f d i f f e r e n c e (Mayr, L i n s l e y and Usinger, 1953) i s c a l c u l a t e d , however, the d i f f e r e n c e s are not l a r g e enough to have s u b s p e c i f i c v a l u e . The c a l c u l a t i o n f o r the comparison between the mainland and the P.m. wardi forms (not s e r i e s #1) i s as f o l l o w s : C D . = Xx - X 2 * 138,5 - 131.5 = 7 - .73 S.ai+S.Oe 5.6+3.9 9.5 The j o i n t nonoverlap per cent i s about 77, w e l l below the conventional l e v e l of accepted s u b s p e c i f i c d i f f e r e n c e o f 9P per cent. The considerable v a r i a t i o n i n s k u l l s i z e i n the species sug-gested the d e s i r a b i l i t y of analyses of covariance, as p r e v i o u s l y mentioned. The analyses revealed t h a t o n l y the r e g r e s s i o n o f p a l a t a l width a t PM 2 on basa l l e n g t h showed a s i g n i f i c a n t d i f f e r -ence i n s l o p e . This suggests t h a t the r a t e a t which s k u l l s widened as t h e i r l e n g t h increased was s t a t i s t i c a l l y the same i n the s e r i e s examined (Table XXXVII..). Table XXXVII;. R e s u l t s of Covariance A n a l y s i s of s i x P a i r s of Measurements taken on S k u l l s from the A r c t i c Mainland and A r c t i c I s l a n d s ,  Slope D i f f . Adjusted Means d.f. F. d.f. F^ Mastoid width on b a s a l l e n g t h 5:62 ,85 5:67 4.12* Greatest zygomatic width on ba s a l l e n g t h 5:56 1.11 5:61 1.57 Width of p a l a t e a t M3 0 n bas a l l e n g t h 5:66 2.C3 5:71 4.49* Width of p a l a t e PM 2 o n b a s a l l e n g t h 5:82 6.OP* 5:87 * Width of p a l a t e a t PM 2 on a l v e o l a r l e n g t h 6:185 .99 6:191 21.84* Greatest zygomatic width on a l v e o l a r l e n g t h 6:89 2.G2 6.95 6.39* • s i g n i f i c a n t 192 -The f a c t t h a t three of the f o u r r e g r e s s i o n s showed a s i g n i -f i c a n t d i f f e r e n c e i n adjusted means, however, would i n d i c a t e the p r o p o r t i o n s between s k u l l l e n g t h and width were s i g n i f i c a n t l y d i f -f e r e n t among the populations sampled. The r e g r e s s i o n c o e f f i c i e n t s of width of p a l a t e at the second premolar and g r e a t e s t zygomatic width a g a i n s t a l v e o l a r l e n g t h , Tables LXV". and LXVT , are p a r t i c u l a r l y i n t e r e s t i n g f o r t h e i r negative v a l u e s . They suggest t h a t the longer the t o o t h row the narrower the s k u l l . There are two p o s s i b l e causes f o r t h i s . I n the f i r s t p l a c e , as the a d u l t muskox gets o l d e r , i t s s k u l l may grow s l o w l y wider* Secondly, i t was n o t i c e d d u r i n g the measure^ ment of a l v e o l a r lengths t h a t o l d b u l l s appeared to have a s h o r t e r t o o t h row, caused, perhaps, by f a l l i n g i n of the t e e t h as. the crowns become worn and the consequent r e d u c t i o n i n s i z e of the a l v e o l i of the t e e t h . I n other words o l d animals may have a wider p a l a t e and a s h o r t e r t o o t h row. T e s t i n g of t h i s theory must await the age analyses of the sample of t e e t h from 189 s k u l l s of the Lake Hazen s e r i e s , should t h a t be p o s s i b l e , but c e r t a i n l y the v i s u a l impression i s as described above. A s u b j e c t i v e character mentioned by A l l e n but c u r i o u s l y enough not explored f u r t h e r by him, i s the presence of s t y l e s on the l i n g u a l s i d e of c e r t a i n upper molars of the muskox. The s t y l e s can best be observed on young (3-7 years old) b u l l s , and are u s u a l l y found on M 2 ? but q u i t e f r e q u e n t l y on M 1 and M3 a l s o . Once the ages of the specimens have been obtained, as mentioned e a r l i e r , i t w i l l be p o s s i b l e t o express the r e l a t i o n s h i p between the presence of s t y l e s and the age of the animals. In b u l l s under three years of 193- -age the t e e t h u s u a l l y have not erupted enough f o r the s t y l e s to be v i s i b l e and i n the o l d i n d i v i d u a l s the t e e t h have been worn down past the s t y l e . I d i d not f i n d s t y l e s on the t e e t h of the 13 O.m. moschatus a d u l t b u l l s or the s i x O.m. niphoecus s k u l l s but found them on O.m, wardi s k u l l s from a l l r e g i o n s . There are not enough specimens of the r i g h t age from the two mainland forms f o r a safe comparison but the evidence does suggest t h a t the presence o f s t y l e s on the upper molars i s a c h a r a c t e r i s t i c of muskoxen of the high A r c t i c and not of the mainland animals. I n t h i s connection i t i s most i n t e r e s t i n g to note t h a t w h i l e the P r i n c e of Wales I s l a n d specimens have the to o t h row l e n g t h o f the c o n t i n e n t a l animals, they bear the s t y l e s of the high A r c t i c muskoxen. The b a s i s f o r the s u b s p e c i f i c s t a t u s of the Wager Bay muskox appears to be tenuous, p a r t i c u l a r l y i n view of i t s geographic pro-x i m i t y to the barren-ground subspecies, w i t h no known b a r r i e r s to p o p u l a t i o n exchanges being present. The graphs i n d i c a t e d t h a t some of the measurements of O.m. niphoecus and of O.m. moschatus were not s i g n i f i c a n t l y d i f f e r e n t , but t h a t others were. This was con-fi r m e d by " t " t e s t s (Table X X X y i J I ) . Previous t e s t s have revealed no s i g n i f i c a n t d i f f e r e n c e i n mean a l v e o l a r lengths between the two named subspecies (Table XXXVX ). S t y l e s were absent from both mainland forms but present i n the populations on the A r c t i c I s l a n d s and Greenland. For the above reasons, as w e l l as the absence of b a r r i e r s to p o p u l a t i o n exchange and the demonstrated v a r i a b i l i t y i n s i z e w i t h i n the A r c t i c I s l a n d s subspecies, I suggest t h a t O.m. niphoecus i s not a v a l i d subspecies. - 194 * Table XXXKCII "T" Test of S i g n i f i c a n c e s of D i f f e r e n c e s i n S k u l l Measurements between O.m. moschatus and P.m. niphoecus Measurement "O.m. moschatus O.m. niphoecus P.o5 N, X S2 d.f. N X S2 d.f. t T o t a l l e n g t h 11 483 357.87 10 6 461 110.5 5 3.08* 2.35 Basal l e n g t h 11 456,5 342.22 10 6 435 90.7 5 3.16* 2.34 P o s t - d e n t a l l e n g t h 13 176.5 148.21 12 6 164 63.05 5 2.67* 2.37 P a l a t a l lengtl to gnathion 7 280 115.24 6 6 265 22.6 5 3.33* 2.46 P a l a t a l width a t PM2 12 58.5 27.15 12 6 53.4 11.76 5 2.50* 2.31 P a l a t a l width a t M3 13 82.8 7.77 12 6 77.5 8.61 5 3.73* 2.45 Greatest zygo * matic width IP 171 36.44 9 6 162.C 41.3C 5 2.77* 2.46 Nasal width IP 79,1 19.33 9 6 68.c 26.58 5 4.28* 2.47 Alveolar length 13 132 4.68 12 6 130 47.1C 5 .699 2.554 P r e a l v e o l a r l e n g t h 11 126.! 62.75 10 6 120 23.65 5 2 . 1 2.37 P o s t p a l a t a l 50.8 26 .69 6 5.69 width 13 12 47.< 5 2.01 2.31 Least distance supraorbital foramen IP 103.5 43.39 9 6 95.1 59.OZ, 5 2.04 2.49 Least width s k u l l behind o r b i t s 11 13.5 91 . 9 10 6 129 100.6 5 1.19 2.45 * s i g n i f i c a n t a t 5 per cent l e v e l . E x t e r n a l Measurements The present study and a survey of the l i t e r a t u r e have y i e l d e d r e l a t i v e l y l i t t l e i n f o r m a t i o n about body measurements of a d u l t cows and b u l l s . A v a i l a b l e i n f o r m a t i o n has been compiled i n Table XXXIX below. Table XXXTX Measurements and Weights of Adult Cow and B u l l , Muskoxen. from the L i t e r a t u r e and i n the Present Study. P l a c e C o l l e c t o r Date Sex T o t a l T a i l Rt. Hind Shoulder Heart Weight Length Length f t . Length Height G i r t h (Lbs.) Thelon G.S. J.S. Tener A p r i l 5/56 Cow 195 cm. 8.5 cm. 43.4 cm. 163.0 cm tt n A p r i l 22/56 Cow Aug. 5/57 Bull 194 6.2 45.5 174.5 tt tt.- 246 14.0 49.0 133.5 cm. 186.0 tt tt Aug. 7/57 B u l l 224 11.5 50.5 136.0 196.0 tt tt Aug. 11/57 B u l l 201.5 14.5 48.0 138.5 192.0 820 l b s . * tt J . J . Teal Aug. 20/54 B u l l 240 17.1 48.3 132.7 C.700 l b s . •Aylmer L. E.T. Seton Aug. 16/07 B u l l 243.8 10.2 48.3 149.9 C.900 l b s . *Thelon R. D.T. Hanbury Aug. 9A899Bull 229.9 5.3 132.1 175.3 579 l b s . L. Hazen J.S. Tener June 2/58 Bull 228,4 14.0 43.0 140,0 180.0 tt tt. J u l y 18/58 B u l l 222.0 218.5 12.5 41.5 126.0 184.0 tt n Aug. 5/58 B u l l 10.0 44.0 138.0 182.0 • M e l v i l l e I . Pa r r y Aug. 9/l820 Bull 208.3 7.6 43.2 142.2 715 l b s . P r i n c e P a t. S.D. I s l a n d Macdonald May 27/49 Bull 200.7 14.0 43.0 tt. tt Oct. 6/49 Bull 229.5 19.0 46.5 tt n May 27/49 Co**. 109.1 15.0 42.5 P r i n c e of Wales I s , T.H. June 19/58 B u l l Manning 210 11.0 45.0 ff: tt June 19/58 B u l l 214 10.0 48,0 * Conversion from inches, 2.54 cm. e q u a l l i n g 1 i n c h . 196 -There are not enough specimens from any area to serve as bases of comparison, p a r t i c u l a r l y between c o n t i n e n t a l and A r c t i c I s l a n d forms. I t would appear, however, t h a t there i s l e s s v a r i a b i l i t y i n the r i g h t h ind f o o t measurement than i n o t h e r s , and t h a t a g r e a t e r number of specimens from Ellesmere I s l a n d and from the A r c t i c mainland may show s t a t i s t i c a l l y s i g n i f i c a n t d i f f e r e n c e s i n the means of t h a t measurement between the populations of the two areas. Measurements of two calves c o l l e c t e d i n A p r i l , 1957, are given i n Table XL... The A p r i l 5th specimen was a f o e t u s , not yet a t term. Table XL... Measurements of C a l f Muskoxen, Thelon Game Sanctuary.  Date Sex Age T o t a l T a i l Right Hi. Heart Weight 1957 Length Length Ft. Length G i r t h A p r i l 5 Female 8 month foetus 71.8cm. 3 cm. 23.2 cm. 46.5 cm. 20 l b s * A p r i l 22 » 24hours 77.2 4.5 25.8 56.5 26 l b s . - 19.7 -D i s c u s s i o n The analyses of the s k u l l measurements I obtained would suggest geographical v a r i a b i l i t y i n s k u l l s i z e and i n the r e l a t i o n -s h i p between i t s l e n g t h and width. I t i s s i g n i f i c a n t , however, t h a t as much v a r i a b i l i t y e x i s t s w i t h i n the subspecies from the A r c t i c I s l a n d s and Greenland as between i t and the mainland forms. An important exception to such v a r i a b i l i t y i s the l e n g t h of the upper to o t h row which has a s i g n i f i c a n t l y g r e a t e r l e n g t h i n the specimens from the higher i s l a n d s . The c o e f f i c i e n t of d i f f e r e n c e value, however, suggests t h a t the d i f f e r e n c e i s not of s u b s p e c i f i c importance i f considered alone. V a r i a t i o n i n mammals may have two causes, one gene t i c and the other environmental. I n a study such as t h i s i t i s v i r t u a l l y im-p o s s i b l e t o separate the two although the data gathered i n the course of n u t r i t i v e s t u d i e s present some i n t e r e s t i n g c o n s i d e r a t i o n s . The Lake Hazen s e r i e s gave the l a r g e s t mean measurements save f o r a l v e o l a r l e n g t h and the l a r g e s t adjusted mean values i n the covariance analyses, except f o r the. analyses of widths of p a l a t e a t PM 2 a n d on b a s a l l e n g t h . A l l other wardi forms, as previously discussed gave lower l i n e a r and r e g r e s s i o n v a l u e s , except f o r tooth row l e n g t h . While the muskox e s s e n t i a l l y i s a non-migratory species, the animals do move from i s l a n d to i s l a n d (Tener, 1954) and i t i s q u i t e u n l i k e l y on geographical grounds t h a t the Lake Hazen animals are i s o l a t e d from the r e s t of the Ellesmere I s l a n d muskoxen o r even from the Greenland animals. I t would suggest t h a t perhaps favour-a b l e environmental c o n d i t i o n s aided the development of l a r g e r animals a t Lake Hazen, - 198 -Those favourable c o n d i t i o n s may have been s u p e r i o r c o n d i t i o n s of food or weather or because of a change i n p o p u l a t i o n d e n s i t y w i t h l e s s competition f o r food resources. There i s some evidence a v a i l a b l e which suggests the l a t t e r , i . e . changes i n s k u l l s i z e w i t h changes i n p o p u l a t i o n d e n s i t y . Eight of the specimens i n the t h i r d O.m. wardi group came from the v i c i n i t y of Lake Hazen c o l l e c t e d by Robert E. Peary, the American e x p l o r e r , and were r e c e i v e d by the American Museum of N a t u r a l H i s t o r y i n February, 1907. The mean b a s a l l e n g t h of the eight was 444 mm. which i s v i r t u a l l y the same as A l l e n ' s f i g u r e f o r 31 a d u l t males from northern Ellesmere I s l a n d but i s 30 mm. l e s s i n l e n g t h than the mean of the 1958 specimens. Mean le n g t h of m a x i l l a r y t o o t h row of recent specimens i s s h o r t e r but i s not s i g n i f i c a n t l y d i f f e r e n t from the e a r l i e r specimens c o l -l e c t e d by Peary. I t i s estimated t h a t Peary shot about 600 muskoxen during h i s attempts to reach the north pole (Hone, 1934). His Eskimos had three hunting camps at Lake Hazen and i t i s probable that severe inroads were made i n the l o c a l muskox p o p u l a t i o n , to the extent o f i t s v i r t u a l e x termination. Today about 200 muskoxen l i v e i n the a r e a . One could conceive, p r i o r to t h e a r r i v a l of Peary and h i s Eskimos, of a muskox po p u l a t i o n l i v i n g at Lake Hazen i n equilibrium w i t h i t s environment, subject t o n a t u r a l m o r t a l i t y f a c t o r s and l i m i t e d i n d e n s i t y i n p a r t , by the demonstrated low food production. With the great r e d u c t i o n i n muskox numbers by Peary's Eskimos, the abundance of food probably would no longer be a l i m i t i n g f a c t o r on growth pf the r e s i d u a l p o p u l a t i o n then or subsequently. The - 199 * g r e a t e r s i z e o f recent specimens may be a r e f l e c t i o n o f l e s s competition f o r f o o d . Another f a c t o r of p o s s i b l e importance may be a s i g n i f i c a n t change i n c l i m a t e i n recent years, w i t h more favourable c o n d i t i o n s f o r p l a n t growth and muskox s u r v i v a l . There i s no evidence f o r t h i s f a c t because of the absence of m e t e o r o l o g i c a l s t a t i o n s i n northern Ellesmere I s l a n d p r i o r to 1947, but i t cannot be d i e * counted. The years i n which the Lake Hazen specimens die d are not known and i t may be p o s s i b l e that.some d i e d during, or p r i o r t o , Peary's time. Many, however, are known to be f a i r l y recent deaths, from the presence of f l e s h and other organic m a t e r i a l s t i l l present, and hence may be considered as r e p r e s e n t a t i v e of the l i v i n g popu-l a t i o n of muskoxen. Vibe (1954) has commented on d i f f e r e n c e i n s i z e of inuskoxen shot i n one area i n Greeland over a 50 year p e r i o d , those c o l l e c t e d i n 1900 being much s m a l l e r . I t i s not known, however, to what extent the p o p u l a t i o n was reduced i n 1900. Dr, Ian McT. Cowan, during the course of measuring a number of s k u l l s f o r the present study i n the Copenhagen Museum, a l s o was s t r u c k by the s m a l l e r size of e a r l i e r specimens. S i z e d i f f e r e n c e w i t h time i s not confined to the high A r c t i c animals. Although the data are much more l i m i t e d , there i s an i n d i c a t i o n t h a t the recent specimens from the Thelon Game Sanctuary are l a r g e r than mainland specimens c o l l e c t e d a t the beginning of the present'century. The mean b a s a l l e n g t h , f o r example, of f o u r a d u l t b u l l s c o l l e c t e d i n the Sanctuary i n 1954 and 1957 was 471.1 mm. w h i l e t h a t of seven c o l l e c t e d between 1875 and 1907 was 448.1. - 20.0 -The m a x i l l a r y tooth row of the recent specimens i s 2 mm, s h o r t e r than t h a t of the o l d e r s e r i e s but i s not s i g n i f i c a n t l y d i f f e r e n t . The p r o b a b i l i t y of shooting a l l s i z e s of a d u l t s i s considered equal and i s given support by the f a c t t h a t n e a r l y a l l specimens were shot f o r meat and not t r o p h i e s . Muskoxen were h e a v i l y hnnted on the Qanadian A r c t i c mainland between 1862 and 1917 and the herds there were e i t h e r exterminated or g r e a t l y reduced (Tener, 1958), Thus a s i t u a t i o n s i m i l a r to t h a t a t Lake Hazen has occurred, the d e s t r u c t i o n of l a r g e numbers of animals w i t h subsequent r e b u i l d i n g of muskox populations l o c a l l y under c o n d i t i o n s of l e s s competition f o r f o o d . The data i n d i c a t e v a r i a b i l i t y then, i n two d i r e c t i o n s , temporal and s p a t i a l . Such v a r i a b i l i t y probably i s p a r t l y the genetic r e s u l t of the r a t h e r sedentary nature of small groups i n a v a s t area of i n s u l a r and c o n t i n e n t a l range, and p o s s i b l y p a r t l y the r e s u l t of r e g i o n a l d i f f e r e n c e s i n n u t r i t i o n . The degree to which g e n e t i c or n u t r i t i o n a l i n f l u e n c e s can be assigned as the b a s i s f o r the de-monstrated d i f f e r e n c e s among the s e r i e s of specimens examined i n t h i s paper, i s a t present unknown. I t i s s i g n i f i c a n t , however, t h a t a f i v e year o l d b u l l h e l d i n c a p t i v i t y i n Vermont, U.S.A., sin c e three months of age and given optimum l i v e s t o c k food, weighs an estimated 1200 pounds, some 300 l b s . heavier than the h e a v i e s t • animal recorded i n the w i l d . The smaller s i z e of the Wager Bay animals and of those from Greenland and the i s l a n d s immediately north of Viscount M e l v i l l e and Lancaster Sounds may r e f l e c t , t h e r e -f o r e , poorer f e e d i n g c o n d i t i o n s , e i t h e r q u a n t i t a t i v e l y or q u a l i t a -t i v e l y , or both. - 201 -I t should be noted t h a t i n s p i t e of the v a r i a b i l i t y i n measurements of s k u l l l e n g t h and width i n the O.m. wardi specimens, the mean m a x i l l a e a l v e o l a r lengths were not s t a t i s t i c a l l y d i f f e r e n t , s p a t i a l l y or temporally, except f o r the s e r i e s from P r i n c e of Wales I s l a n d c o l l e c t e d i n 1958 whose mean a l v e o l a r l e n g t h was not s t a t i s -t i c a l l y d i f f e r e n t from the mainland form. The r e l a t i v e u n i f o r m i t y o f the a l v e o l a r lengths suggests t h a t i t may not be subject to v a r i a t i o n s of the f a c t o r s promoting s k u l l growth as other measure-ments. Experimental evidence o b v i o u s l y i s needed to t e s t the i n -f l u e n c e of n u t r i t i o n on the s i z e and a l l o m e t r i c growth of muskox s k u l l s . The P r i n c e of Wales I s l a n d s e r i e s are most i n t e r e s t i n g i n the evidence they show of p o s s i b l e i n t e r g r a d a t i o n between the mainland form and the form from the higher A r c t i c I s l a n d s . I t may be, of course, t h a t the s e r i e s i s only a small toothed v e r s i o n of the O.m. wardi subspecies, but i t a l s o may r e f l e c t the i n f l u e n c e of genes from mainland forms. P o s s i b l e Environmental Infl u e n c e s on Muskox V a r i a b i l i t y .  F o s s i l records of muskoxen have been suggested as i n d i c a t i n g t h a t the genus Ovibos must have occupied an environment during e a r l y , middle and l a t e P l e i s t o c e n e times s i m i l a r to that of today (Nathorst, 1901; Lynge, 1930). Species contemporary wi t h i t and s t i l l i n exist e n c e today i n c l u d e the c a r i b o u , lemming and ptarmigan. Other contempory s p e c i e s , now e x t i n c t , i n c l u d e the wo o l l y mammoth and the w o o l l y rhinoceros (Lynge, op. c i t ; Richardson, l $ 6 l ) . - 20.2 -During the P l e i s t o c e n e the immediate p r o g e n i t o r s of e x i s t i n g muskoxen were d i s t r i b u t e d over a l a r g e p a r t of northern E u r a s i a , Alaska and western and c e n t r a l North America ( A l l e n , 1913; Seton, 1929). Their remains have been found i n England, Germany, France, A u s t r i a , Norway, European R u s s i a , S i b e r i a , A l a s k a , B r i t i s h Columbia, A l b e r t a , Kansas, Iowa, Indiana and Pennsylvania, I n p r e h i s t o r i c times the European and A s i a n r e p r e s e n t a t i v e s became e x t i n c t but the North American forms have s u r v i v e d to t h e present i n A r c t i c r e g i o n s of Canada and Greenland. Two arguments have been put forward f o r the disappearance of muskoxen from the Old World and from c e n t r a l North America. Stefansson (1924) b e l i e v e s t h a t p r i m i t i v e hunters exterminated the animals, but F i e l d e n ( i n Nares, 1878) and Hone (1934) have postu-l a t e d t h a t the muskox became e x t i n c t i n those regions because of changes i n environment w i t h the r e t r e a t of g l a c i e r s and the general warming of the world's atmosphere and s u r f a c e . What p r e c i s e l y happened may never be l e a r n e d , but what i s known today of the habits o f the species would lend credence to the l a t t e r hypothesis. I n other words, the muskox has e x i s t e d i n the tundra biome f o r many thousands of years and presumably to some extent i s adapted morpho-l o g i c a l l y and p h y s i o l o g i c a l l y to t h a t biome. Major c l i m a t i c changes, w i t h consequent changes i n the nature and extent of vegeta-t i o n , would have a l t e r e d the tundra biome to t h a t of the b o r e a l f o r e s t or even to the deciduous f o r e s t or p r a i r i e which covers areas today i n North America once i n h a b i t e d by muskoxen, profoundly a l t e r i n g the h a b i t a t to which muskoxen are adapted. - 203 -Another f a c t o r which may have had some i n f l u e n c e on t h e i r disappearance i s the p o s s i b i l i t y of the f a i l u r e of muskoxen to compete s u c c e s s f u l l y w i t h other l a r g e herbivores i n the changing environment of i n t e r g l a c i a l p e r i o d s , so tha t species w i t h a higher r e p r o d u c t i v e r a t e and b e t t e r a d a p t a b i l i t y i n t h e i r food h a b i t s may have d i s p l a c e d muskoxen. Subspeciation, or the genet i c f i x i n g of c e r t a i n c h a r a c t e r i s -t i c s i n a group of animals, r e q u i r e s a degree of geographical i s o l a t i o n , otherwise gene f l o w i s great enough t o prevent morpho-l o g i c a l and p h y s i o l o g i c a l changes. Today, as p r e v i o u s l y i n d i c a t e d , Canadian muskoxen l i v e i n small groups over an area of about 900,000 square m i l e s , some animals being p a r t l y i s o l a t e d on i s l a n d s and others being e q u a l l y i s o l a t e d on the A r c t i c mainland because of the vast d i s t a n c e s i n v o l v e d . I n both cases, however, some gene f l o w probably e x i s t s among groups, even on the i s l a n d s . Movements across the sea i c e have been documented f o r many years. Even though the tundra biome extends over a ve r y l a r g e area, i t i s v a r i a b l e , w i t h i n l i m i t s , i n i t s c h a r a c t e r i s t i c s , p a r t i c u l a r l y i n the q u a n t i t y and q u a l i t y of v e g e t a t i o n . The present study has revealed some of those c h a r a c t e r i s t i c s and t h e i r d i f f e r e n c e s a t the northern and southern extremity of muskox d i s t r i b u t i o n and i t has been p o s t u l a t e d t h a t geographic v a r i a t i o n i n s i z e of animals may be p a r t l y the r e s u l t of d i f f e r e n c e s i n d i e t . The very u n i f o r m i t y of the A r c t i c tundra, however, reduces the opp o r t u n i t y f o r a l a r g e h e r b i v o r e ' t o d i f f e r e n t i a t e i n t o a d a p t i v e l y s p e c i a l i z e d groups. The absence of e f f e c t i v e geographical b a r r i e r s , the r e l a t i v e l y uniform environment and the slow r a t e of i n c r e a s e i n - 204 -the species are c o n t r i b u t i n g t o genetic homogeneity of the animal. The r e s u l t s of t h i s are to be seen i n my e a r l i e r t r e a t -ment of the v a r i a t i o n w i t h i n the s p e c i e s . Conclusions As s t a t e d at the beginning of t h i s s e c t i o n , s k u l l and body measurements have been considered here i n the examination of v a r i a t i o n of muskoxen. Other f a c t o r s such as horn shape and c o l o u r and pelage c o l o u r must be evaluated before f i n a l conclusions about muskox s u b s p e c i a t i o n can be drawn. On the b a s i s of the s k u l l data alone, i t would appear t h a t the muskox would have to be con-s i d e r e d a monotypic species which shows considerable geographic v a r i a b i l i t y i n absolute s k u l l s i z e and i n s k u l l p r o p o r t i o n s . The s i g n i f i c a n t l y g r e a t e r t o o t h row l e n g t h and the presence of l i n g u a l s t y l e s on the upper molars of the high A r c t i c forms, i n d i c a t e a degree of d i f f e r e n t i a t i o n which, w i t h other morphological characters, may prove to be of s u b s p e c i f i c v a l u e . Of these d i f f e r e n c e s , I b e l i e v e the most important i s the presence of s t y l e s . F u rther examination of a l a r g e r number of specimens of the r i g h t sex and age c l a s s e s from the A r c t i c mainland of Canada must be examined before f i n a l conclusions may be reached. There i s s u f f i c i e n t evidence, however, from s k u l l measurements and to o t h c h a r a c t e r i s -t i c s , to suggest t h a t the subspecies niphoecus i s not v a l i d and t h a t the muskoxen i n the Wager Bay r e g i o n , t h e r e f o r e , belong to the subspecies moschatus. Pending the a d d i t i o n a l studies of pelage • c o l o u r , horn form and c o l o u r and body measurements, no changes i n nomenclature are proposed a t t h i s time. - 205 -Conclusions o f Study, 1, The a n a l y s i s of a l i m i t e d number of s o i l samples from muskox ranges near Lake Hazen, Ellesmere I s l a n d , suggests t h a t s o i l s t here compare fav o u r a b l y i n t h e i r c o n s t i t u e n t s w i t h s o i l s of some regions of southern A l b e r t a , S o i l s from the Thelon Game Sanctuary were of lower value. 2, Ranges stud i e d i n the Sanctuary c a r r i e d a higher p r o p o r t i o n of woody species than d i d Lake Hazen ranges, 3. While the a r e a of bare ground on n e a r l y a l l ranges s t u d i e d was s i m i l a r i n extent, the annual t o t a l p r o d u c t i o n of new growth of food species per acre of summer range was about seven times g r e a t e r i n the Thelon area than a t Lake Hazen. Thelon w i n t e r ranges produced s i x to ten times as much annual growth of food p l a n t s . A comparison between muskox ranges and those used by mountain sheep and e l k i n Jasper and Banff N a t i o n a l Parks o f A l b e r t a show tha t the Thelon w i n t e r ranges produce almost as much forage as park ranges. The Lake Hazen w i n t e r range examined, however, produced about o n e - t h i r d to one-fourteenth as much forage. 4, Based on the obtained range production f i g u r e s , one acre of Thelon summer range s t u d i e d would support 1.6 a d u l t 800 l b # muskoxen per month. One acre of summer range s t u d i e d a t Lake Hazen would support .232 a d u l t 800 l b . muskoxen per month. I n other words, Thelon summer range studied may support up to seven times as; many muskoxen as an area of comparable s i z e a t Lake Hazen. 5. Thelon w i n t e r ranges s t u d i e d may support up to ten times as many muskoxen as Lake Hazen w i n t e r ranges of comparable s i z e . 6. N u t r i t i v e analyses of muskox foods on the Thelon summer ranges, suggest t h a t they provide adequate amounts of p r o t e i n , carbo-- 206 -hydrates, calcium and phosphorous, w i t h perhaps l e s s f a t than d e s i r a b l e . 7. Lake Hazen summer foods gave lower values o f p r o t e i n and f a t than Thelon foods, but probably are adequate f o r muskoxen requirements. Calcium content appeared to be s u f f i c i e n t , as d i d t h a t of phosphorous. 8. Thelon w i n t e r range foods probably c o n t a i n s u f f i c i e n t protein, f a t , carbohydrate, and calcium f o r maintenance of l i f e . Phosphorous values are below those recommended f o r a good d i e t i n range c a t t l e . 9. The n u t r i t i v e values of Lake Hazen w i n t e r range foods are d i f f i c u l t to i n t e r p r e t but the analyses would suggest t h a t A r c t i c w i l l o w and sedge (Carex stans Drej.) o f f e r s u f f i c i e n t p r o t e i n , f a t , carbohydrate, calcium and probably phosphorous f o r maintenance. 16. Comparison between c a t t l e ranges of southern A l b e r t a and Saskatchewan and muskox ranges of the Thelon area suggests t h a t apart from low phosphorous values and somewhat lower pro-t e i n content o f w i n t e r foods, the Thelon forage sample values were e q u a l l y as good or s u p e r i o r . The Lake Hazen range samples a l s o compared f a v o u r a b l y w i t h c a t t l e range forage samples, i n chemical v a l u e s . 11. Summer food h a b i t s t u d i e s of Thelon muskoxen i n d i c a t e d t h a t w i l l o w ( p a r t i c u l a r l y S a l i x a l a x e n s i s ) i s the s t a p l e item of d i e t , and t h a t sedges and grasses a l s o were .consumed. Winter foods c o n s i s t e d of shrubby s p e c i e s , such as labrador t e a , crow-ber r y , cowberry, b i l b e r r y and ground b i r c h . - 207 -12. Summer food of Lake Hazen muskoxen c o n s i s t e d of w i l l o w , sedge ( p a r t i c u l a r l y Carex stans Drej»), blue grass and f o r b s . Winter foods, as determined from stomach contents and the i d e n t i f i c a -t i o n of w i n t e r ranges by dung, i n c l u d e d w i l l o w , f o x t a i l , sedge and dryas. 13. Muskox populations i n Canada i n general are s l o w l y i n c r e a s i n g , w i t h the exception of c e r t a i n A r c t i c I s l a n d s , notably P r i n c e P a t r i c k I s l a n d . The species appears t o be reoccupying s l o w l y ranges forme r l y depleted by explorers and robe hunters. Information c o l l e c t e d during the present study suggests t h a t about 1,500 muskoxen are on the A r c t i c mainland of Canada and about 3,500 on the A r c t i c I s l a n d s . 14. Herds i n the Thelon Game Sanctuary i n summer were l a r g e r than those found on Ellesmere I s l a n d , p o s s i b l y because of gr e a t e r annual production of food species i n the Sanctuary. 15. S o l i t a r y b u l l s are more numerous i n summer than i n w i n t e r . 16. C a l f p r o d u c t i o n i n the Thelon Game Sanctuary, i n f i v e years between 1951 and 1957, v a r i e d between none ( s m a l l sample) and 14.3 per cent, w i t h most years producing over 10 per cent. 17. C a l f production at Fosheim Peninsula and a t Lake Hazen, E l l e s -mere I s l a n d i n ; f i v e years between 1950 and 1959, v a r i e d between none and 12.2 per cent, w i t h three years producing between 6.9 and 7.7 per cent. 18. Y e a r l i n g s c o n s t i t u t e d between 4.0 and 9.8 per cent of muskoxen observed i n the Sanctuary i n the years 1952, 1953| 1955, 1956, 1957, g i v i n g a t e n t a t i v e s u r v i v a l of calves t o the f i r s t year o f l i f e o f about f i f t y per cent. 208 -19. At Fosheim P e n i n s u l a y e a r l i n g s i n 1951 were 3.4 per cent of herds st u d i e d , g i v i n g a rough estimate of s u r v i v a l of calves from the 1950 c a l f crop of l e s s than f i f t y per cent. At Lake Hazen y e a r l i n g s c o n s t i t u t e d $.0 per cent of the herd animals observed i n 1958 and were 6.5 per cent of herd animals i n 1959• The 1959 f i g u r e i n d i c a t e d t h a t e i t h e r a l l c a l v e s produced i n 1958 s u r v i v e d to 1959 or th a t the 1958 and 1959 samples were not r e p r e s e n t a t i v e of the t o t a l p o p u l a t i o n . 20. There i s i n s u f f i c i e n t i n f o r m a t i o n to assess the e f f e c t of wolf p r e d a t i o n on the numbers of muskoxen. 21. The a n a l y s i s of muskox f a t , the f i r s t such a n a l y s i s , revealed a f a t t y a c i d known p r e v i o u s l y o n l y i n sheep, supportingSimpson's (1945) and Moody's (1958} conclusions about muskox phylogeny* 2 2 . The a n a l y s i s of muskox m i l k , which had not been done p r e v i o u s l y , showed th a t i t had a r e l a t i v e l y high f a t content, a f a c t o r of s u r v i v a l value to ca l v e s . 23. Rumen c i l i a t e s of muskoxen have been described f o r the f i r s t time, and were noted to be s i m i l a r to those of the r e i n d e e r . 2 4 . A s e r i e s of organ weights from a d u l t muskox b u l l s has been obtained f o r f u t u r e r e f e r e n c e . Increases i n l i v e r weights w i t h time i n three Lake Hazen specimens suggest a s i g n i f i c a n t storage of food reserves i n summer. 2 5 . Anal temperatures of f o u r a d u l t b u l l s are s i m i l a r to those reported f o r beef c a t t l e . a n d Columbia b l a c k - t a i l e d deer, and i n d i c a t e t h a t p h y s i o l o g i c a l adaptation to c o l d has not been achieved by a lowered body temperature. 209 26* Three species of nematodes and three species of cestodes were i d e n t i f i e d during post mortem examinations of muskox specimens* F i r s t r.ecords were obtained of the nematode Nematodirella  l o n g i s p i c u l a t a (Romanovitch, 1915) and of the cestodes (Echinococcus granulosus (Patsch, 1786) Neither p a r a s i t e s nor disease are considered to cause s i g n i f i c a n t m o r t a l i t y of muskoxen, 27* Only s i x of 462 s k u l l s examined i n the f i e l d and i n museums c a r r i e d a l v e o l a r l e s i o n s of e x o s t o s i s . 28, The muskox e x h i b i t s a number of adaptations to A r c t i c l i v i n g . I t s short limbs, dense i n n e r and outer h a i r and i t s g e n e r a l l y slow movements c o n t r i b u t e to heat c o n s e r v a t i o n . As a ruminant, the muskox synthesizes Vitamin B and p r o t e i n s . Food probably i s s t o r e d i n summer i n the l i v e r f o r w i n t e r use. L a c t a t i o n i s prolonged, up to 15 months a t l e a s t , which would a s s i s t c a l f s u r v i v a l during w i n t e r . The ungulate eye permits f e e d i n g during w i n t e r darkness, Muskoxeniare cosmopolitan f e e d e r s , e s s e n t i a l i n areas where p l a n t growth i s sparse:,.. Feeding i s not i n t e n s i v e i n an area, as herds are widely s c a t t e r e d and move f r e q u e n t l y . Apart from s o l i t a r y b u l l s i n summer, muskoxen move i n herds, g i v i n g p r o t e c t i o n to each other from predators and s e r v i n g to keep the sexes together i n a l a r g e country where the fewness of the animals may mean missed o p p o r t u n i t i e s f o r conception, 2 9 , Factors l i m i t i n g the growth of muskox populations i n the Canadian A r c t i c have yet to be f u l l y d e f i n e d . Future s t u d i e s of muskoxen may show th a t the u l t i m a t e l i m i t to t h e i r population 210 growth i s s e t by food through i t s i n f l u e n c e on r e p r o d u c t i o n , s u r v i v a l of young and the t o t a l numbers of the animals a given area w i l l support. 30. L i m i t e d u t i l i z a t i o n of muskoxen i n c e r t a i n areas of the Canadian A r c t i c can be permitted f o r s c i e n t i f i c purposes. There are not yet s u f f i c i e n t numbers of the animals to permit n a t i v e hunting, which i n any event w i l l have to be w i t h i n the framework of the l i m i t a t i o n s of the tundra environment and the species p r o d u c t i v i t y . 31. Future s t u d i e s of muskoxen should be d i r e c t e d t o environmental f a c t o r s c o n t r o l l i n g t h e i r numbers and l a b o r a t o r y s t u d i e s should be c a r r i e d out to e l u c i d a t e the physiology o f t h i s ungulate. 32. A study i n v a r i a t i o n i n s k u l l s i z e of the three subspecies suggests t h a t the muskox i s a monotypic s p e c i e s . There i s good evidence, based on s i g n i f i c a n t d i f f e r e n c e s i n a l v e o l a r lengths and on the presence of s t y l e s t h a t the muskoxen of the A r c t i c I s l a n d s , apart from those on P r i n c e of Wales I s l a n d , are a separate subspecies, but f u r t h e r study m a t e r i a l i s required before d e f i n i t e conclusions can be drawn. - 211 -Acknawl edgements. In a study of t h i s s o r t , one i s indebted to many i n d i v i d u a l s i n many walks p f l i f e . I n some cases, no data at- a l l would have been obtained without t h e i r help and i n others my work was made much e a s i e r and much more pleasant because of t h e i r a s s i s t a n c e , I am p a r t i c u l a r l y g r a t e f u l to Mr. W. Winston Mair, C h i e f , Canadian W i l d l i f e S e r v i c e , f o r h i s constant support of the f i e l d program and f o r h e l p f u l c r i t i c i s m and a d v i c e during the w r i t i n g o f t h i s t h e s i s , and to Mr. T.H. Manning, Ottawa, f o r great a s s i s t a n c e i n the s t a t i s t i c a l procedures. I am i n debt to Mr. J.P. K e l s a l l , Mr. A.G. Loughrey and to other members of the Canadian W i l d l i f e S e r v i c e , f o r Many f i e l d o b s e r v a t i o n s . To a l l i n d i v i d u a l s and o r g a n i z a t i o n s who c o n t r i b u t e d so generously of t h e i r knowledge and t e c h n i c a l a s s i s t a n c e , I am deeply g r a t e f u l , e s p e c i a l l y to Dr. R.B. Carson, Department of A g r i c u l t u r e , Ottawa. Dr. Ian MoT. Cowan, Head, Department of Zoology, U n i v e r s i t y of B r i t i s h Columbia, provided encouragement and v a l u a b l e advice during the p r e p a r a t i o n of t h i s t h e s i s . To him and to Drs. P.A. L a r k i n and J.F. B e n d e l l , I express my warm a p p r e c i a t i o n f o r c o n s t r u c t i v e c r i t i c i s m s . - 212 -B i b l i o g r a p h y . A l l e e , W . C , A l f r e d E. E m e r s o n , O r l a n d o P a r k , Thomas P a r k and 1949 K a r l P . S c h m i d t , The p r i n c i p l e s o f a n i m a l e c o l o g y . P h i l a . and L o n d o n , W . B . S a u n d e r s C o . , 837 p p . A l l e n , J . A . , 1913 O n t o g e n e t i c and o t h e r v a r i a t i o n s i n m u s k - o x e n , w i t h a s y s t e m a t i c r e v i e w o f t h e m u s k - o x g r o u p , r e c e n t and e x t i n c t . Mem. Am. M u s . N a t . H i s t . , N o . 1 , P a r t 4 : 1 0 3 - 2 2 6 . A n d e r s o n , R . M . , 1930 N o t e s on t h e m u s k - o x and t h e c a r i b o u , p p . 4 9 - 5 3 i n Hoare ( 1 9 3 0 ) . 1946 C a t a l o g u e o f C a n a d i a n r e c e n t mammals. B u l l . N a t . M u s . C a n a d a , No . 1 0 2 , B i o l . S e r . 3 1 , v i + 2 3 8 p p . Anonymous 1939 F o o d a n d l i f e . Y e a r b o o k o f A g r i c u l t u r e 1 9 3 9 . U . S . D e p t . o f A g r i c u l t u r e . G o v t . P r i n t i n g O f f i c e , Wash. D . C . 1950 Commit tee on a n i m a l n u t r i t i o n . N a t i o n a l R e s e a r c h C o u n c i l . Wash. D . C . 1951 The C a n a d i a n A r c t i c . C a n . G e o g r . I n f . S e r . 2 . D e p t . o f M i n e s & T e c h . S u r v e y s , O t t a w a . 118 p p . 1954 Addendum t o Volume 1 , o f c l i m a t i c summaries f o r s e l e c t e d m e t e o r o l o g i c a l s t a t i o n s i n C a n a d a . A v e r a g e v a l u e s o f t e m p e r a t u r e a n d p r e c i p i t a t i o n . M e t . D i v . , D e p t . o f T r a n s p o r t , T o r o n t o . 29 P P . 1 9 5 7 A t l a s o f C a n a d a . D e p t . o f M i n e s a n d T e c h . S u r v e y s , O t t a w a . (7) p . 110 m a p s . A ' s d e l l , S . A . , 1949 N u t r i t i o n and t h e t r e a t m e n t o f s t e r i l i t y i n d a i r y c a t t l e : A r e v i e w . J o u r . D a i r y . S c i . X X X I I ( l ) : 6 0 - 7 0 - 213 -a Back, G., I836 N a r r a t i v e of the A r c t i c l a nd e x p e d i t i o n to the mouth of the Great F i s h R i v e r and along the shores of the A r c t i c Ocean i n the years 1833, 1834, and 1835• London, J , Murray, 663 pp. Bandy, P.J., W.D. K i t t s , A.J. Wood and I . McT. Cowan, 1957 The e f f e c t of age and the plane of n u t r i t i o n on the blood chemistry of the Columbian b l a c k - t a i l e d deer (Odocoileus hemionus columbianus). B. 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Publ. 3151, 255 pp. Thompson, Daniel Q., 1955 The r o l e of food and cover i n population fluctuations of the brown lemming at Point Barrow, Alaska. Trans. 20th N.A. W i l d l . Conf., 166-176 pp. Thompson, W.R., 1939 Parasitology. 31:299-388. Vibe, Chr., 1954 Problemerm omkring Grjzflands moskusoksen. Soertry Af T i d s s k i f t e t Gr^land, 401-414 pp. 1958 The muskox i n east Greenland. Mammalia 22 (l):l68-174. W a l l s , Gordon Lynn, 1942 The ve r t e b r a t e eye and i t s adaptive r a d i a t i o n . Cranbook I n s t , of S c i . B u l l . 19, 785 pp. Watkins, W.E., 1937 The calcium and phosphorous content of important New Mexico range' forages. N.M. Agr. Exp, S t a t i o n Tech, B u l l . , 246. Wyatl; F.A., W.E. Bowser and W. Odynsky, 1939 S o i l survey of Lethbridge and Pincher Creek Sheets. Univ. of A l t a . C o l l e g e of A g r i . B u l l . 32:98 pp. J.D. Newton, W.E. Bowser and W. Odynsky, 1941 S o i l survey of M i l k R i v e r Sheet. Univ. of A l t a . C o l l e g e of A g r i . B u l l . 36:105 pp. Zimmerman, F.A.W., 1780 C i t e d i n A l l e n . - 225 -Appendix - I • » 226 Graphs o f t h e ^ S t a t i s t i c a l Treatment of Measurements i n M i l l i m e t e r s of S e r i e s of Adult B u l l Muskox S k u l l s . For each p o p u l a t i o n the range of v a r i a t i o n i s shown by a heavy h o r i z o n t a l l i n e ; the mean (x) by a small v e r t i c a l l i n e . The blackened p a r t of each bar comprises two standard e r r o r s of the mean on e i t h e r s i d e of the mean. One-half of each b l a c k bar plus the white bar at e i t h e r end o u t l i n e one standard d e v i a t i o n on e i t h e r s i d e of the mean. - 227 -Tables of the S t a t i s t i c a l Treatment of Measurements i n M i l l i m e t e r s of S e r i e s of Adult B u l l Muskox S k u l l s .  Table XLI T o t a l Length -OTJIT. O.ta. *—U.m. * O.m. *—O.M. *—O.mV* N 11 6 3 12 17 24 26 X_ 483 461 480 469 478 466 510 Sx'2 3578.75 552.5 263.2 6277.75 792.1 3482 5.704 4.290 4.465 4.804 3.79 2.31 357.87 110.5 239.27 392.36 344 139.28 S .O . 18.917 10.51 15.468 19.808 18.58 11.801 9s 2.852 2,145 2.233 2.40 1.89 1.157 C.V. 3.916 2.279 3.298 4.149 3.987 2.314 Oc.v, . .590 .465 .476 .531 .407 .277 * (1) P r i n c e o f Wales I s l a n d . * (2) P r i n c e P a t r i c k , M e l v i l l e , C o r n w a l l i s and Devon I s l a n d s . * (3) Northern Ellesmere. * (4) North and East Greenland. * (5) Lake Hazen, Ellesmere I s l a n d . Table XLII.  Basal Length O.m. O.m. O.m. O.m. O.m. O.m. O.m. moschatus niphoecus wardi( 1 ) wardi ( 2 ) wardi ( 3 ) w a r d i (4)wardl(5) " 1 I I o 3 17 : 24 ' 29 ~ X 456.5 435 451 437 444.5 433 474 Sx2 3422.25 453.5 2521.25 6538.75 7575 3397 Bx 5.58 3.81 4.02 4.901 3.70 2.45 342.225 90.7 210.104 408.67 329.347 121.32 S.D. 18.499 9.523 14.495 20.21 18.15 11.014 &s 2.840 1.943 2.013 2.45 1.85 1.023 C.V. 4.052 2.189 3.316 4.547 4.19 2.323 Oc.v. .641 .477 .460 .551 .427 .216 - 228 -Table XLIII Least Orbital Width OT5u O.m. O.m. U7m~, OTnu OTnu moschatus niphoecus wardi(1) wardi(2) wardi(3) wardi(4) " 1 i l 5 7 33 15"" 25 " X 0 198.5 185.5 197 191 190 183 Sx 2 2862.25 640 812 1896 2635 5071.25 ©x o 4 .283 4.526 4.39 3 .486 3.3125 3.03 S 2 238.52 128 135.3 158 175.66 2 2 0 . 4 8 9 S.D. 15.44 11.314 11.633 12.569 13.25 14.85 G-s 2.141 2.309 2.199 1.745 I . 6 5 6 1.51 C.V. 7.78O 6.099 5 .905 6.581 6.973 8.114 Ocv. 1 .08 1.245 1.116 .914 .872 .828 Table XLIV Palatal Length O.m. O.m. O.m. O.m. O.m. O.m. moschatus niphoecus wardi(1) wardi(2) wardi(3) wardi(4) N 7 6 3 12 16 15 X 280 265 264 260 264 256.5 Sx2 693.25 113 1260.25 1916.75 2197.50 ex 4.509 1.901 3.089 2.826 3.235 S2 115.24 22.6 114.57 127.783 156.964 S.D. 10.739 4.754 10.704 11.304 12.53 es 2.03 .970 1.545 1.413 1.62 C.V. 3.835 1.794 4.116 4.282 4.89 8c.v .725 .366 .594 .535 .63 Table XL¥: Greatest Zygomatic Width O.m. O.m. O.m. O.m. O.m. O.m. O.m. moschatus niphoecus wardi(l) wardi(2) wardi(3) wardi(4) wardi(5 ) " T 10 ' 6 5 I4 24 24 X 171 162 168 163 163.5 173 177 Sx2 3 2 8 . 0 0 2 0 6 . 5 0 136.O 528.25 9 7 3 . 6 6 4 * 1 . 5 857 & X o . i # ? 7 ° 2 - 5 7 0 1 « ^ 5 7 1.703 1.784 3 . 4 2 1.246 S2 3 6 . 4 4 4 1 . 3 0 17.0 4 0 . 6 3 5 57.270 2 8 1 . 8 0 37.26 S.D. 6 . 0 3 7 6 . 4 2 6 4.123 6.374 7.567 16.787 6.104 0s .954 1.311 .729 .852 .891 1.712 .623 C.V. 3 . 5 3 0 3 . 9 6 6 2.454 3.910 4 . 6 2 8 9 . 7 0 3 . 4 4 8 8c.v. .556 . 8 0 9 .434 .522 .545 . 9 9 .352 - 229 -Table XLVI. Mastoid Width O.m. O.m. O.m. O.m. O.m. O.m. O.m. moschatus niphoecus wardi (1) wardi (2) wardi (3) wardi M) wardi (5) N 13 6 8 10 17 23 20 I 173 169 180 177 175 165 193 Sx2 22S4.5 91.2$ 335 744.25 2286 3014 1157 ex o 3.742 1.709 2.446 2.875 2.899 2.440 1.745 S2 182.04 18.25 49.86 82.694 142.875 137.00 60.9 S.D. 13.492 4.272 6.918 9.093 11.953 11.705 7.804 ©s 1.871 .872 1.223 1.43 1.449 1.220 .872 C.V. 7.799 2.527 3.843 5.137 6.830 7.09 4.043 ©c.v. 1.08 1.709 .679 .812 .828 .739 .452 Table XLVII Distance between Lambdoidal Crest and anterior edge of Nasals  O.m. O.m. O.m. O.m. O.m. O.m. N . 11 6 2 9 l y 22 X 412 390.5 392.75 387.5 394 389 Sx2 3870.75 751.75 1609.0 7826 5169.75 ©x o 5.932 4.90 4.727 5.364 3.345 S2 387.075 150.35 201.125 489.125 246.18 S.D. 19.674 12.261 14.182 22.116 15.69 ©s 2.965 2.503 2.364 2.682 1 .67 C.V. 4.775 3.139 3.659 5.613 4.033 ©c.v. .7198 .640 .61 .680 .429 Table XLVIII  Post-dental Length O.m. O.m. O.m. O.m. O.m. O.m. moschatus niphoecus wardi(1) wardi(2) wardi(3) wardi(4) 1[ H 6 8 14 18 24 X 176.5 164 177 168.5 169 163 Sx^ 1778.50 315.25 224 1137.29 2396.25 4074.25 Ox 3 .377 3.174 2 . 0 0 2.499 2.798 2.71 S< 148.208 6 3 . 0 5 3 2 . 0 8 7 . 4 8 4 140.956 177.141 S.D. 12.174 7 . 9 4 0 5.657 9.353 11.873 1 3 . 3 1 Os 1 .69 1.620 1 . 0 0 0 1.249 1.39 1.36 C.V. 6 . 8 9 7 4 . 8 4 1 3.196 5.551 7.025 8.165 ©cv. .956 . 9 8 8 .565 .742 .827 .833 - 230 -Table XLIX  Basioccipetal Width O.m. O.m. O.m. O.m. O.m. O.m. N 13 6 8 13 i d 24 53 52.1 52.4 51.1 49.5 47.2 Sx2 439.02 55.69 43.05 173.91 290.85 543.98 9x 1.677 1.335 .87 1.056 .978 .992 S2 36.58 11.14 6.15 14.492 17.108 23.65 S.D. 6.048 3.338 2.479 3.807 4.148 4.86 Gs .839 .681 .438 .528 .489 .495 C.V. 11.411 6.406 4.733 7.449 8.380 10.29 9-c.v. 1.582 1.307 .836 1.033 .988 1.05 Table L Least Width of Skull between Horns and Orbits O.m. O.m. O.m. O.m. O.m. O.m. moschatus niphoecus wardi(1) wardi(2) wardi(ft) wardi(4) N 11 6 8 14 17 24 X 138.5 129 145 136.5 133.5 128 Sx2 919 503 429 1083.25 908.75 2755.25 Ox 2.890 4.01 2.767 2.439 1.827 2.233 S2 91.9 100.6 61.29 83.33 56.79 119.79 S.D. 9.586 10.03 7.828 9.128 7.536 10.94 Gs 1.445 2.047 1.384 1.219 .913 1.11 C.V. 6.921 7.775 5.398 6.874 5.64 8.54 9c. v. . 1.043 1.587 .954 .918 .683 .811 Table LI Greatest Orbital Width O.m. O.m. O.m. O.m. O.m. O.m. moschatus niphoecus wardi(1) wardi(2) wardi(3) wardi(4) N 12 6 6 10 15 24 X 259.5 249.5 271.5 257.0 254.5 249 Sx2 3743.5 515.50 401.50 1071.75 3477.25 4174.00 ex 5.116 4.060 3.656 3.460 4.069 2.749 S2 340.31 103.1 80.3 119.083 248.375 181.48 S.D. 18.447 10.15 8.956 10.94 15.759 13.47 es 2.662 2.092 1.832 1.73 2.034 1.37 C.V. 7.109 4.068 3.298 4.257 6.192 5.409 e c v . 1.026 .830 .675 .673 .799 .552 - 231 -Table LII Palatal Width at M3 O.m. O.m. O.m. O.m. O.m. O.m. O.m. moschatus niphoecus wardi(1) wardi(2) wardi(3)wardi (4)wardi (5) 13 b 21 14 1 8 24 - 38 8 2 . a 77.5 8 2.0 8 0.5 79.9 8 1.5 84.0 Sx 2 101.01 43.07 190.0 249 . 0 8 435.05 676.17 444.00 © X .773 1.174 .672 1.169 1.192 1.10 .562 S2 7.77 8.614 9.5 19.160 25.591 29.398 12.00 S.D. 2.787 2 . 9 3 4 3 . 0 8 2 4.377 5.059 5.42 3.464 ©s . 3 8 6 .599 .336 .585 .596 .553 . 2 8 0 C.V. 3.365 3.785 3.758 5.437 6.331 6.650 4.124 ©c.v. .467 . 7 7 2 . 4 1 0 .726 .746 .679 .334 Table LIII  Premaxillae Width O.m. O.m. O.m. O.m. O.m. O.m. N 11 6 X 50.5 51 Sx2 362.81 91.49 ©X 1.816 1.711 S2 36.281 18.298 S.D. 6.023 4.277 ©s .908 .873 C.V. 11.926 8.386 ©c.v. 1.798 1.712 3 54.3 12 17 24 50.4 46.7 47.0 139.38 364.12 423.45 1.032 1.157 .875 12.67 22.757 423.45 3.574 4.770 4.290 .516 .578 .438 7.091 10.21 9.128 1.023 1.24 .931 Table LIV Nasal Width O.m. O.m. O.m. O.m. O.m. O.m. moschatus niphoecus wardi(1) wardi(2) wardi(3) wardi(4) ^ ^ g 9 — 18 23 X 79.7 68.9 72.9 72.9 68.7 70.0 Sx* 173.94 132.91 226.68 457.32 1417.12 1301.44 ©x 1.39 2.062 2.01 2.564 2.152 1.603 S2 19.327 26.58 32.38 59.16 83.360 59.15 S.D. 4.396 5.155 5.690 7.692: 9.130 7.69 ©s .695 1.052 1.006 1.282 1.076 .802 CV. 5.516 1.527 7.805 10.551 13.289 10.98 P c* v- .872 2.062 1.379 1.76 1.57 1.14 - 232 -Table LV Nasal Length O.m. O.m. O.m. O.m. O.m. O.m. moschatus niphoecus wardi(1) wardi(2) wardi(3) wardi(4) "I I T X 157.5 Sx2n34.25 3.211 S 2 113.425 S.D. 10.650 Os 1.605 C.V. 6.762 0<5.v. 1.019 T 148.5 141.5 2.128 28.3 5.32 1.085 3.582 .731 2 152.5 I F 151.5 511.75 3.023 73.107 8.550 1.51 5.644 .997 17 151.5 1740.5 2.529 108.781 10.429 1.265 6.884 .835 19 151.5 1504.5 2.097 83.58 9.142 1.04 6.034 .692 Table LVI Least Distance Between Supraorbital Foramina X Sx2 Ox S2 S.D. 0s C.V. Oc.v. O.m. moschatus — I D O.m. O.m. O.m. O.m. O.m. 103.5 390.50 2.083 43*39 6.587 1.041 6.364 1.006 •6 . 8 14 18 15 95.4 101.0 100.0 . 95.4 98 295.21 296.05 646.18 932.68 312.17 3.08 2.299 1.884 1.746 1.219 59.04 42.29 49.71 54.86 22.29 7.684 6.503 7.050 7.407 4.722 1.568 1.149 .942 .873 .609 8.054 6.438 7.050 7.764 4.818 1.644 1.138 .942 .915 .620 Table LVII  Prealveolar Length O.m. moschatus ~ u 1 X 126.5 Sx 2 627.50 Ox S2 S.D. Ss C.V. Oc.v. 2.39 62.75 7.921 1.194 6.261 .944 O.m. niphoecus 6 120 119.25 1.945 23.65 4.863 .992 4.052 .827 O.m. O.m. O.m. O.m. wardi(l) wardi(2) wardi(3) wardi(4) 3 126 11 120 493.25 2.117 49.325 7.023 1.059 5.852 .882 17 118 1187.00 2.089 74.187 8.613 1.044 7.299 .885 24 116 1528.75 1.69 66.467 8.27 • 844 7.129 .727 - 233 -Table LVIII  Alveolar Length O.m. O.m. O.m. O.m. O.m. O.m. O.m. moschatus niphoecus wardi(l) wardi(2) wardi(3) wardi(4) wardi(5) T 13 6 23 14 1 8 ^ 24 147 X o 132 130 132 136.5 140 139 138 Sx2 56.25 235.5 710 131 588.50 811 4602 Ox .600 2.745 1.184 .848 1.387 1.21 .463 S2 4.687 47.100 » 32.27 10.08 34.617 35.26 31.52 S.D. 2.165 6.863 5.680 3.174 5.884 5.94 5.614 Os .300 1.400 .592 .424 .658 .60 .231 C.V. 1.64 5.279 4.303 2.325 4.203 4.27 4.068 ©c.v. .227 1.007 .448 .310 .495 .435 .167 Table LIX  Post-palatal Width O.m. O.m. O.m. O.m. O.m. O.m. moschatus niphoecus wardi(1) wardi(2) wardi(3) wardi(4) N T3 b 8 13 18 24 X 50.8 47.2 46.2 47.1 47.2 46.O S X2 320.36 28.48 70.20 197.83 263.79 356.24 6x 1.433 .954 1.12 1.126 .928 .802 S2 26.69 5.696 10.03 16.485 15.517 15.489 S.D. 5.166 2.386 3.167 4.060 3.939 3.93 Os .712 .487 .572 .563 .464 .41 C.V. 10.169 5.055 6.855 8.620 8.345 8.543 ©c.v. 1.410 1.031 1.212 1.195 .983 .871 Table LX  Width of Palate at PM: O.m. O.m. O.m. O.m. O.m. O.m. O.m. moschatus niphoecus wardi(1) wardi(2) wardi(3) wardi(4)wardi(5) " 1 11 ^ 22 14 18 —24 102 X 58.5 53.4 55.0 52.5 53.8 53.3 58.5 Sx^ 325.88 58.79 233 244.80 486.23 514.95 1417.50 ©x 0 1.445 1.371 .710 1.159 1.225 .965 .370 Sd 27.15 11*76 11.1 18.830 27.01 22.39 14.032 S.D. 5.210 3.429 3.331 4.339 5.197 4.73 3.746 Os .722 .699 .355 .579 .612 .482 .185 C.V. 8.906 6.421 6.056 8.265 9.660 8.87 6.403 ©c.v. 1.235 1.310 .646 1.104 1.138 .905 .317 Table LXI  Mastoid Width on Basal Length D.F. Sx2 Sxy. §y2_ Regress. Coeff. D.F. Dev i a t i o n s from Regr t Sy2-(Sxy)2 Mean — A d j . S t . e r r o r s x 2 Square ft of f O.m. O.m. O.m. moschatus 10 3422.2 niphoecus 5 453*3 wardi(2) O.m. wardi(3) O.m. wardi(4) O.m. wardi(5) W i t h i n Regr. Coeff. Common Ad j . Means T o t a l 1804.75 1948.0 .5273 69.00 90.88 .1522 8 1869.23 1081.53 672.22 .5786 16 6538.62 3573.0 2286.0 .5464 22 7370.65 2458.49 3013.31 .3335 7 638.0 130.0 598.0 .2037 20292. 9116.77 8608.41 .4493 35130.7 17001.2314128.59 .4839 9 996.24 110.69 170.85 2.4756 4 80.38 20.095 177.81 3.5450 7 46.45 6.6357 183.71 2.9062 15 333.55 22.736 179.68 2.0777 21 2193.28 104.4419 174.52 2.1147 6 571.51 95.2516 183.72 3.2142 62 4221.41 68.087 5 291.03 58.20 67 4512.44 67.349 5 1388.54 277.71 5900.98 Test of s i g n i f i c a n c e of slope d i f f e r e n c e s F - | | a i g - = .854 d.f. 5:62 F at P.05 - 2.365 G O • U O / According t o Table of " F " (Snedecor, 1956), slopes are not s i g n i f i c a n t l y d i f f e r e n t . Test of s i g n i f i c a n c e of adjusted means F = 2 7 7 . 7 O =L.123 d.f. 5:67 F at P.05 = 2.355 67.35 Therefore adjusted means are s i g n i f i c a n t l y d i f f e r e n t . Table LXII Greatest Zygomatic Width on Basal Length Regress D.F. Sx2 Ssy. Sy 2 Coeff, Deviations from Regr. Sy 2-(3xy) 2 Mean Adj. St. error D.F. -5x2-*- Square f o f j O.m. moschatus O.m. niphoecus O.m. wardi(2) O.m. wardi(3) O.m. wardi(4) O.m. wardi(5) Within Regr. Coeff. Common Adj. Means Total 7 1846.47 441.44 5 473.30 173.0 12 2441.08 918.56 16 6538.50 2143.75 14 3805.4 1854 8 993.60 125.7 276.9 .23907 206.3 .3655 519.23 . 3762 955.P .3278 1526.5 .4872 160.0 .1265 62 16098.35 5657.45 3643.93.3514 67 31612.45 11623.28 6139.93 .3677 6 171.36 28.56 166.15 1.8460 4 143.1 35.77 167.50 2.1268 11 172.83 15.71 167.65 1.4445 15 252.14 16.81 165.72 1.2642 13 623.23 47.94 168.88 1.3673 7 144.1 20.6 170.92 1.7641 56 1506.76 26.91 5 148.97 29.79 61 1655.73 27.14 5 210.55 42.64 66 1866.28 Test of significance of slope differences F = 2 ? ' f f i = 1.107 d.f. = 5:56 F at P.05 = 2 . 3 8 2o.91 According to Table of "F", slopes are not significantly different. Test of significance of adjusted means F = 42.64 = 1.571 d.f. = 5:61 F at P.05 = 2 . 3 7 27.14 Therefore there are no significant differences i n adjusted means. Table L X I I I  Width of Palate at PM 2 on Basal Length Sxv Sv< Regress. Coeff. D.F. 0 , Devia t i o n s S y M S x y K Mean S x 2 Square from ftegr. Adj. S t . e r r o r i _ oX_£ O.m. moschatus 10 O.m. niphoecus 5 O.m. wardi(2) 12 O.m. wardi(3) 16 O.m. wardi(4) 23 O.m. wardi(5) 22 3422.2 899.0 286.34 .2627 453.3 108.15 58.79 .2385 2441.08 566.86 232.17 .2322 6538.6 1447.4 481.08 .2214 7543.63 1647.07 484.47 .2183 2691.83 158.6 121.91 .0589 W i t h i n Regr. Coeff. Common Adj . means T o t a l 88 23090.64 4827.08 1664.76 . 2095 46482 8513.7 2323.87 .1831 9 4 11 15 22 21 82 5 87 5 50.18 32.99 100.54 160.69 124.85 28.47 487.42 168.42 655.66 105.17 760.83 5.57 8.25 9.14 0.71 5.675 1.35 5.94 33.68 7.53 21.03 56.81 57.04 55.31 55.14 57.04 57.43 .5605 .7514 .5105 .4464 .3755 .4733 33^68 = 5 # 6 7 d # f < m 5 . g 2 F at P.05 - 2.33 5.94 Test of s i g n i f i c a n c e i n slope d i f f e r e n c e s F Therefore according t o n F M Table, slopes are s i g n i f i c a n t l y -d i f f e r e n t . Test of s i g n i f i c a n c e i n adjusted means: si n c e slopes are s i g n i f i c a n t l y -d i f f e r e n t , d i f f e r e n c e s of adjusted means w i l l t e s t s i g n i f i c a n t l y . Table LXIV  Width of Pa l a t e at M3 on Basal Length D.F. S x 2 Sxy O.m. moschatus 10 3422.2 251.22 100.69 Regress. Sy2 Coeff. D.F. De v i a t i o n s from Regr. Sy2-(SxyK Mean Adj. S t . e r r o r Sx* Square f \ of f 70734 9 52733 $.205 1.05U9 .0861 4 39.62 9.905 80.05 1.4185 .2419 11 102.72 9.338 82.56 1.0058 .2253 15 1.51 .1006 80.83 .8465 .1602 22 493.67 22.439 84.39 .7351 -.0392 5 12.16 2.432 80.17 1.4292 66 732.53 11.0989 5 112.85 22.57 .1663 71 845.38 11.9067 5 267.20 53.44 .1360 1112.58 O.m. niphoecus O.m. wardi(2) O.m. wardi(3) O.m. wardi(4) O.m. wardi(5) W i t h i n Regres. Coeff. Common Adj. Means T o t a l 5 12 16 23 6 453.3 2441.1 6538.6 7543.6 827.43 39.03 590.67 1473.56 1208.71 -32.42 42.98 245.64 333.60 687.34 13.43 21226.24 3530.77 1432.68 33639.45 4575.79 1735.50 Test of s i g n i f i c a n c e of slope d i f f e r e n c e s F = | i i i 2 - 2.035 d.f. = 5:66 F at P.05 - 2.36 Therefore according t o "F R Table, slopes are not s i g n i f i c a n t l y d i f f e r e n t . Test of s i g n i f i c a n c e o f d i f f e r e n c e s of adjusted means F = = 4.490 d.f. = 5:71 F at P.05 = 3.21 Therefore according to "F", adjusted means are s i g n i f i c a n t l y d i f f e r e n t . Table LXV Width of Pal a t e at PM 2 on A l v e o l a r Length D.F. Sx* _Sxy_ Sy* D e v i a t i o n s from Regr. Regress. S y 2 - ( S x y ) * Mean Adj. S t . e r r o r Coeff. D.F. S x 2 Square ft of ft 23.2318 14.675 10.6125 16.5375 28.430 23.0259 .1604 9.2023 9.09 9.199 200.73 .8481 1.2513 .6561 .8104 .7145 .6412 .3152 O.m. moschatus O.m. niphoecus O.m. wardi(1) O.m. wardi{2) O.m. wardi(3) O.m. wardi(4) O.m. wardi(5) W i t h i n Regres. Coeff. Common Adj. means T o t a l 12 5 21 13 17 23 55.77 204.83 645.82 130.36 587.11 803.49 101 3515.26 - 48.59 - 4.33 -112.54 - 73.73 -135.68 -105.68 -776.0 297.88 58.79 231.86 240.15 486.23 520.47 187.34 .871 -.021 •.174 -.565 -.231 ..131 -.220 11 4 20 12 16 22 100 255.55 58.70 212.25 198.45 454.88 506.57 16.04 57.93 52.43 54.15 52.84 54.93 54.20 58.98 5942.64 -12 56.55 2022.72 -.2114 7363.8 -1302.89 3191.91 -.1769 185 1702.44 6 54.59 191 1757.03 6 1204.36 2961.39 Test of s i g n i f i c a n c e of slope d i f f e r e n c e s F = = .988 d.f. = 6:185 F at P.05 = 2.15 Therefore according t o "F" Table, slopes are not s i g n i f i c a n t l y d i f f e r e n t . Test of s i g n i f i c a n c e of d i f f e r e n c e s among adjusted means: F = 2°Q»73 = 21.84 d.f. - 6:191 F at P.05 - 2.14 9.19 Therefore according t o "F" Table, adjusted means are s i g n i f i c a n t l y d i f f e r e n t . Table LXVI Greatest Zygomatic Width on A l v e o l a r Length D.F. S X2 Sxv Sv2 Regress. Coeff. D.F. De v i a t i o n s from Regr. Sy 2-(Sxyj' t M e a n Adj. S t . e r r o r • Sx2 Square y of f O.m. moschatus 9 25.4 - 33.8 327.6 -1.3307 8 282.7 35.34 169.39 3.0532 O.m. niphoecus 5 204.84 - 168.20 206.34 .8211 4 68.23 17.06 160.24 3.9820 O.m. w a r d i ( l ) 7 139.5 - 70.5 135.5 - .5053 6 99.87 16 .64 165 .78 3.4492 O.m. wardi(2) 13 130 .36 - 217.21 527.8 -1.6662 12 165.9 13.82 163.53 2.6268 O.m. wardi(3) 17 587.11 - 41.2 977.0 - .0701 16 974.11 60.88 165 .73 2.2983 O.m. wardi(4) 23 803.49 - 699.8 6482.9 - .3709 22 5873.41 266.97 174.44 1.9898 O.m. wardi(5) 22 791.83 - 279.13 345 .65 - .3525 21 747.26 35.58 178.84 2.0324 W i t h i n 89 7957.05 89.40 Regr. Coeff. - .4138 6 1086.5 181.07 Common 2682.53 -1109.99 9502.79 95 9043.5 95.19 Adj. means 6 3654.06 609.01 T o t a l 3938.98 - 803.65 12861.52 - .2040 12697 .56 Test of s i g n i f i c a n c e of slope d i f f e r e n c e s F = = 2.0254 d.f. = 6:89 F a t P.05 = 2.20 S9.40 Therefore according t o n F " Table, slopes are not s i g n i f i c a n t l y d i f f e r e n t . Test of s i g n i f i c a n c e of adjusted means d i f f e r e n c e s F = 609.01 m 6.3978 d.f. = 6:95 F a t P.05 = 2.19 95»19 Therefore according t o rtFn Table, adjusted means d i f f e r s i g n i f i c a n t l y . - 240 -Figures of the S t a t i s t i c a l Treatment of Measurements i n M i l l i m e t e r s of S e r i e s of Adult B u l l Muskox S k u l l s .  500 520 .figure 6 ' .otul length tmbt.8 n . a c i m t i - s wardi U ) L v i n o a BOS«tuitui .-*.--dl 13)' v-Tlu^s ^csc^itiia .;;irdi 12) Ovlooa aoactwtua *c*rdi ( 1 ) LV1.03 ...osenatua Bi^.ioseua ovibun . . .(-sc:^tt:s mTai ( i j ovibos a e s e J u t t t u . ^ r d i f3) i/Vil)03 OOSOMtUt .fardi (2) tv lboa ...oacriutua .mrdl (Xj (JYIOOS ...ouchatua nijhoucus t y i s o a mo»ea«t'aJ :joschutu3 200 240 lAnat, o r b i t a l ..idt:; ) it© 190 ; QBWtast zyronat lc -vldtJi ^vl&oa itioachatus wardi (5)1 • Cvlou^fioa.cautua ward! U ) f tvlboo fflosohatua . * i r d i (3) tv looa mosc.iiitus ;« i rd i (2) Lviboa ;.osc:;utus M T d l (1)' avisos ...oschatus .OUCUE • Vl O.T J:i03C!lutu3 r.osctiutus J 2 i o Utrioos mosRhutaa [ / J C v l b o n mosehfcttta .it»rdi l Oviboa B0«'ch*tai .*urdl (2j ovitjos jauacutua *urd i ( 1 ) Ovlboa moacuutua niplibe vHi'ji Monctiutua moBrtiutus-,1c 270 2 8 0 Figura 9 P a l a t a l :.•:."„:. t » i o u a apMa -«tua j » r d l (2) U V I S O J soacn^tua . .ami (l> ! C - t ' - " U ) ' iCTlbo. aoicnutua . .ardf (3)1 Ovlooa mOBCaatua ;1, (jvlboa .".03ctu«iu3 nii-.oQcus •** ' Cvl c;; moic .litua lonohitua 2§0 300 Ovlboa moschatus **irdl (5) uvlooa . o o c y t e ' s Martfjt {/,) fi&jfhju rwoehutiea a i r d i (3) Ovisca r.ooc J* ' .U5 . ^ r d l (2.) uviboa aoichi i tul ^ i r d l 11) C T I O O B dosc.lutua nixioucual 'Ovlboa r . onc i . a t ca ..o::chatua •i-vipos r:onc~atu.- U l <.vJhQS [.one a t u - ^ur-! 1 (3) Cvlboa b,ij3c:iatu3 . .anil ( i ) Ovibos ..oacaatus -airdl ( l j .uviboa moschatus m^hoccus H O 160 180 200 2JC 1 " j i j u r a 13 P o . t d . n U H langth »- 2 i f 2 itiutus * « r d i f T ] 125 130 i J 5 :' " : ~ ^ F t g U r « 22 ' ; • |7 P r e a l v e o l a r length! 1 135 U O ; U 5 150 j f i g u r e 23 A l v e o l a r length / l g u r e 24" it PoetpalMtmJ. «ldtfc| jOrlooe aoecuutuj 15 iurioom soaehMtcs .m - t V l b o - : mojJ.c'.jTiin ( OYiboe . isr: ward i (1, •jt-Tlboe aoacautua ni;.::oeeuai Gviboa mosehiitua . ..^a-Miatua eldtu Of pala te et a F i g . 27. Base camp during winter s t u d i e s . Thelon Game Sanctuary. March 26-A p r i l 29, 1956. F i g . 29. Attungala, Eskimo a s s i s t a n t beside a d u l t cow muskox c o l l e c t e d i n Thelon Game Sanctuary. A p r i l 5, 1956. F i g . 28. Herd of 30 muskoxen on f l a t p l a t e a u country, n o r t h of Thelon R i v e r . March 28, 1956. • F i g . 30. K n i f e i n d i c a t e s t y p i c a l l y shallow snow cover over Ledum decumbens. A p r i l 4, 1956. F i g . 31. Muskox fe e d i n g areas on pl a t e a u north of Thelon R i v e r * Snow cover has been pawed away on dark areas. A p r i l 4, 1956. F i g . 3 3 . W. Holsworth beside S a l i x a l a x e n s i s bushes on Transect 1. Thelon Game Sanctuary. J u l y 2 3 , 1957. F i g . 3 2 . W. Holsworth viewing f l u v i a l w i l l o w f l a t of Transect 1 of summer range s t u d i e s , Thelon Game Sanctuary. J u l y 2 3 , 1957* F i g . 3 4 . Summer Range study area I I , Thelon Game Sanctuary. J u l y 3 0 , 1957. - 246 -F i g . 35. W. Holsworth on winter range study area I , Thelon Game Sanctuary. J u l y 31, 1957. F i g . 36. Winter range study area I I , Thelon Game Sanctuary. August 3, 1957. Photographs i n Figures 37, 38, 42 to 51 were taken by Dr. James Soper, Department of Botany, U n i v e r s i t y of Toronto F i g , 37, Panoramic view to the north-west of the base camp ( r i g h t ) a t Lake Hazen, Ellesmere I s l a n d , Note t y p i c a l d i s t r i b u t i o n of w i l l o w clumps. Mount Ubyssey i s a t r i g h t c e n t r e , August 13, 1958, F i g , 38, Panoramic view to the north-east, i l l u s t r a t i n g f l a t lands between h i l l s and Lake Hazen, Mount Ubyssey i s a t l e f t and Johns i s l a n d at r i g h t , August 13, 1958, -» 248 F i g . 3 9 . P a n o r a m i c v i e w f r o m e a s t end o f L a k e H a z e n , l o o k i n g s o u t h w e s t down t h e l a k e . N o t e r a n g e o f h i l l s and E l l e s m e r e i s l a n d I c e Cap on r i g h t . June 2 6 , 1 9 5 8 . F i g . 4 0 . T y p i c a l l a t e w i n t e r snow c o v e r i n v a l l e y s . Snow Goose r i v e r v a l l e y , L a k e H a z e n . June 4 , 1 9 5 8 . F i g . 4 1 . S n o u t o f unnamed g l a c i e r f r o m i c e c a p . N o t e muskoxen f e e d i n g on h i l l s i d e a t r i g h t . June 1 8 , 1 9 5 8 . F i g . 42. Summer range a t the fo o t of Mt. Ubyssey, Lake Hazen. J.S. Tener measuring v e g e t a t i o n . Note muskox at f o o t of pale h i l l . J u l y 22, 1958. F i g . 44. Transect 1, p l o t 11, of summer range study. P l a n t s i n -cluded S a l i x a r c t i c a . Dryas i n t e - g r i f o l i a . Kobresia myosuroides.. Lake Hazen"! J u l y 22, 1958. F i g . 43. Transect 1, p l o t 1, of summer range study. P l a n t s i n c l u d e d Poa glauca. Melan- drium t r i f l o r u m . Erysimum  p a l l a s i i . Agropyron l a t i g l u m e , e t c . Lake Hazen. J u l y 22, 1958. F i g . 45. Transect 1, p l o t 25, summer range study. P l a n t s i n c l u d e d Oxyria digyna and Agropyron l a t i g l u m e . Lake Hazen* J u l y 22, 1958. F i g . 46 . T r a n s e c t 1 , w i n t e r r a n g e s t u d y , 1 4 8 0 T above s e a l e v e l . J . S . T e n e r m e a s u r i n g v e g e t a t i o n . P l a n t s i n c l u d e d C a r e x s t a n s . E r i o p h o r u m s c h e u c h z e r i . S a x i f r a g a  s p . , Po lygonum v i v i p a r u m . S a l i x  a r c t i c a . L a k e H a z e n . J u l y 2 3 , 1958". F i g . 4 8 . T r a n s e c t 1 , w i n t e r r a n g e s t u d y . Note d e n s i t y o f v e g e t a t i o n s u c h as S a l i x a r c t i c a . C a r e x s t a n s . S a x i f r a g a h i r c u i u s i s i n c e n t r e . L a k e Hazen^ J u l y 2 3 , 1 9 5 8 . F i g . 4 7 . T r a n s e c t 1, p l o t 1 8 , w i n t e r r a n g e s t u d y . D r i e r p a r t o f t h e u p p e r v a l l e y below M t . U b y s s e y . P l a n t s i n c l u d e d A r c t o g r o s t i s l a t i f o l i a . S a l i x  a r c t i c a , D r y a s i n t e g r i f o l i a , L u z u l a s p . A l o p e c u r u s a l p i n u s . L a k e H a z e n . J u l y 2 3 , 1 9 5 8 . " F i g . 4 9 . T y p i c a l d e n s i t y o f C a r e x s t a n s . g r o w i n g i n wet s t r e a m b e d s . M t . U b y s s e y , L a k e H a z e n . J u l y 22, 1 9 5 8 . F i g . 5 0 . T r a n s e c t 2, w i n t e r r a n g e s t u d y , 1680 1 above s e a l e v e l , a t f o o t o f M t . U b y s s e y . L a k e H a z e n . J u l y 23, 1 9 5 8 . F i g . 52. P i t dug by a muskox o n a 1630 f t . r i d g e o n s l o p e o f M t . U b y s s e y . L a k e H a z e n . J u l y 23, 1958. F i g . 5 1 . Remains o f an a d u l t b u l l muskox i n c r e e k bed on s l o p e a t f o o t o f M t . U b y s s e y . L a k e H a z e n . J u l y 22, 1 9 5 8 . * 252 -Appendix I I 253 T h e o r e t i c a l C o n s i d e r a t i o n of the I n t r i n s i c Rate of N a t u r a l Increase.  by P.H. L e s l i e , We w i l l assume t h a t an imaginary p o p u l a t i o n of muskoxen i s censused immediately a f t e r the breeding season each year; i . e . t h a t the census dates are e x a c t l y one year apart and we w i l l c o nfine our a t t e n t i o n to the female p o p u l a t i o n o n l y . Consider now the l i f e h i s t o r y of a group of female calves aged 0 - W a t some census (where W i s the leng t h of the breeding season). For s i m p l i c i t y we may drop the W and c a l l t h i s the group of n females aged 0 at the census taken a t t=0. They w i l l then be aged x a t census taken at t=x. 1. I t i s assumed t h a t no i n d i v i d u a l d i e s u n t i l the age of 25 years and t h a t a female gives b i r t h to a c a l f every a l t e r n a t e year s t a r t i n g when she i s aged 4 years, the sex r a t i o at b i r t h being 1:1. Then f o l l o w i n g out the h i s t o r y of n Q females aged 0 Age a t Census No. of 9 0 n 1 n 2 n 3 n 4 n+Jn»cows and calves 5 n(+Jn)= cows and calves s t i l l w i t h Q's 6 n(+^n)+in= cows and new Thus each group of n^ Q aged 3 a t same census w i l l have produced I n-j calves before the next census, and each group of n^ aged 5 w i l l have produced \ n^ before the next census and so on f o r each a l t e r n a t e age group. Then i f we s t a r t our imaginary p o p u l a t i o n - 254 ~ w i t h any a r b i t r a r y age d i s t r i b u t i o n of females, n 0 , n ^ n 2 , e t c . , i t may be shown u l t i m a t e l y t h a t the r a t e of i n c r e a s e of the po p u l a t i o n X = e r per year. r i s given by the r e a l p o s i t i v e root o f the equation i 2 6 - i ( A 2 2 ^ 2 0 ^ 8 ^ A 2) •= o (a female aged 25 does not l i v e t i l l the next year and th e r e f o r e cannot produce any young). W r i t i n g /* L =*A 2, t h i s equation may be w r i t t e n /u« (/i2„ /a m i ) . i Q The d e r i v a t i o n o f that equation i s as f o l l o w s Z^ 1 3- i (/>" + /»10+ / i 9 + /tt) . o / a l 3 - i /* (A 1 0 + A 9 + /** + D = o /H13* £ /u ( ^ i L l l ) - 0 M u l t i p l y throughout by (/* i ) (/al4 B / » 1 3 B j / i ( / u l l ^  D » o D i v i d e throughout by /* /u!3 . /ttl2 . j / i l l + i . o o r / u l 3 „ / i l 2 _ j / i l l = _ i / ^ l l (/u2 _ /U j ) . ' .1 » 5 By t r i a l and e r r o r the equation can be so l v e d . /* cannot be gre a t e r than /u2 /u „ 1 = o - 1+ • 2 a 2 ^ = L 3 6 6 2 2 and s t a r t i n g from t h i s we o b t a i n roughly t h a t f o r Q /* ° 1.355 or s i n c e /\ = r~/** k " I - " or r = 0.148 per annum ( l o g e • r ) Thus u l t i m a t e l y the p o p u l a t i o n w i l l i n c r e a s e 1.16 times every year a t a r a t e of 16 per cent, i . e . i f you had 100 female i n -d i v i d u a l s a t one census, at the next you would have 116. I t i s a l s o u s e f u l to consider the r a t e r defined by N - N t e r o r A • e r , r - l o g Q * 0.148 per annum I f the p o p u l a t i o n were i n c r e a s i n g continuously (which i t i s not as there i s a d e f i n i t e p e r i o d i n the year a t which b i r t h s take place) the p o p u l a t i o n would double i t s e l f i n l o g e 2 • 4.7 years r and quadruple i t s e l f i n l o g e ^ - 9.3 years r But as we are only d e a l i n g w i t h a d i s c r e t e and not a continuous process, we o n l y can say t h a t the p o p u l a t i o n would be approxima-t e l y doubled i n 5 years and quadrupled i n 9 yea r s . 2 We now assume t h a t 50% of calves d i e i n t h e i r f i r s t ; year i n order to see what e f f e c t t h i s would have on the r a t e of i n c r e a s e . Thus, the r a t e s which have been c a l c u l a t e d so f a r represent the maximum p o s s i b l e i f the b i o l o g i c a l assumptions are c o r r e c t , s i n c e we have assumed t h a t the i n d i v i d u a l s are immortal u n t i l 25 years o f age. I f we had assumed they l i v e d to 100 years, the answer would be very l i t t l e d i f f e r e n t : i n f a c t J\ cannot be greater than 1.17 The equation now to be solved i s ^ (/A2 - /I - = 4 256 -from which we have Z1 s 1*18 approx. l\ * 1,086 and r » 0.083 per annum Thus the e f f e c t of a 50% m o r t a l i t y of calves i n t h e i r f i r s t year of l i f e i s to reduce the r a t e q u i t e c o n s i d e r a b l y , A p o p u l a t i o n of 100 females would i n c r e a s e to 109 i n a year (or 9%) and the p o p u l a t i o n would approximately double i n 8 years and quadruple i n 17 y e a r s . Again these must be o u t s i d e f i g u r e s ( i f 50% m o r t a l i t y of calves i s c o r r e c t ) as no allowance has been made f o r any a d u l t m o r t a l i t y . I t p o i n t s up the f a c t t h a t the muskox po p u l a t i o n i n the w i l d must be r a t h e r p r e c a r i o u s l y balanced. The s t a b l e age d i s t r i b u t i o n of t h i s imaginary p o p u l a t i o n w i l l be a m u l t i p l e o f : Age 0 .2 1 /\ -1 2 A -2 3 k -3 • • 24 /\"-24 25 A - 2 5 T o t a l 2/^-1 A- 1 so t h a t the p r o p o r t i o n of c a l v e s and y e a r l i n g s i n the female p o p u l a t i o n w i l l be which f o r ^ - 1.086 i s 0.214 i . e . 21% approximately of the female p o p u l a t i o n w i l l be female calves and y e a r l i n g s . There w i l l be,however, some d i f f i c u l t y i n 257 r e l a t i n g t h i s f i g u r e to any observations i n the f i e l d owing to d i s p e r s i o n of the p o p u l a t i o n i n t o s o l i t a r y animals and w i d e l y s c a t t e r e d herds. The p r o p o r t i o n of ca l v e s « 2. i . 2 X -1 N.B. ( 0. calves \ = 2 (A*lj ( t o t a l female popi 2 A"*1 - »172 1.1772 - 14% 3 To take another extreme-nsuppose th a t female muskoxen d i d not bear a c a l f every a l t e r n a t e year, but every year s t a r t i n g a t the same age as before. Then we have an equation: which reduces, i n the same way as before t o l*z t k< V - i ) - - i Without determining the a c t u a l r o o t of t h i s equation we can s t a t e t h a t i t cannot be g r e a t e r than the ro o t o f the equation ^ - A 3 * i • 0 f o r which f\ l i e s between 1.25 and 1,26 or r cannot be g r e a t e r than a f i g u r e somewhere; between .22 and .23 per annum, 4 I f , as bef o r e , we a l s o consider a 50% m o r t a l i t y of calves then the equation to be solved i s the r o o t of which cannot be gr e a t e r than/^- 1.16 or r - .15 Th i s l a s t f i g u r e i s the same as the o r i g i n a l one when i t was assumed t h a t breeding took place every a l t e r n a t e year and t h a t 258 -there was no calf mortality. A l l female muskoxen do not breed every year and therefore these figures must represent outside l i m i t s . Thus to summarize on the basis of the biological information obtained, the intrinsic rate of increase of the muskox population, even under the most favourable circumstances, cannot be greater than 15-23 per cent per annum and the optimum figure i s probably nearer to 15 than 23, If a 50 per cent mortality of calves i s a reasonable figure to assume on the basis of f i e l d studies, then the i n t r i n s i c rate can-not be greater than a figure between # and 15 per cent. As some cow mortality does take place during adult l i f e and as no calves survive i n some years, the figure w i l l be lower yet. A l l of the above calculations are carried out inrterms of an imaginary population of females, assuming an equal sex ratio of calves. But i f the proportion of males of a l l ages remains f a i r l y constant then the rate of increase could also apply to the popu-lation as a whole. Reprinted from Canadian Journal of Zoology, 34 : 569-571. 1956 GROSS COMPOSITION OF MUSK-OX MILK 1 B Y J . S. T E N E R A b s t r a c t A sample of musk-ox milk was analyzed for its nutritional components. Fat content was found to be 11.0%, protein content 5.3%, and lactose content 3.6%. The vitamin B ] 2 content was 3.4 /igm. per liter. A s p a r t of the c o n t i n u i n g s t u d y b y the C a n a d i a n W i l d l i f e Serv ice of the b i o l o g y of m u s k oxen, a five weeks ' s u r v e y was u n d e r t a k e n in M a r c h a n d A p r i l , 1956, on par t of the w i n t e r range of those a n i m a l s in the eastern p o r t i o n of the T h e l o n G a m e S a n c t u a r y , N o r t h w e s t T e r r i t o r i e s . A n a d u l t cow m u s k ox was col lected there, on A p r i l 22, under p e r m i t f r o m the D e p a r t m e n t of N o r t h e r n A f f a i r s a n d N a t i o n a l Resources, O t t a w a . T h i s cow had g i v e n b i r t h to a calf about 24 hr . p r e v i o u s l y , and as she was l a c t a t i n g , 76 g m . of m i l k was col lected i m m e d i a t e l y after d e a t h b y d i g i t a l m a n i p u l a t i o n of the udders and b y excis ion of the g l a n d . T h e m i l k was p u t i n t o a p las t i c bot t le and preserved w i t h corros ive s u b l i m a t e . T h e sample , w h i c h then froze, became c u r d l e d after i t h a d been t h a w e d , b u t d i d not sour. T h e m i l k was a n a l y z e d b y D r . R . R . R i e l , C h e m i s t r y D i v i s i o n , Science Service , D e p a r t m e n t of A g r i c u l t u r e , O t t a w a , and a v i t a m i n B u d e t e r m i n a t i o n was made b y D r . J . A . C a m p b e l l , F o o d a n d D r u g D i r e c t o r a t e , D e p a r t m e n t of N a t i o n a l H e a l t h and W e l f a r e , O t t a w a . F a t and t o t a l sol ids were d e t e r m i n e d b y the M o j o n n i e r m e t h o d . P r o t e i n s a n d non-ac id-prec ip i tab le prote ins were d e t e r m i n e d b y the s e m i m i c r o - K j e l d a h l m e t h o d . Lac tose was es t imated b y the anthrone m e t h o d , except t h a t the developed color was measured at 620 ix w i t h a B e c k m a n M o d e l D U spectro-photometer , and ash was d e t e r m i n e d a c c o r d i n g to the A . O . A . C . m e t h o d . T h e results of the analyses are g i v e n i n T a b l e I. F a t content averaged 11 .0%, proteins 5 . 3 % , a n d lactose 3 .6%. T h e v i t a m i n B i 2 content was f o u n d T A B L E I G R O S S C O M P O S I T I O N O F M U S K - O X M I L K I N P E R C E N T A G E S Constituent Average % of 2 samples Water Total solids Fat Solids not fat Proteins Non-acid-precipitable proteins Acid-precipitable proteins Lactose Ash Vitamin .B12 78.5 21.54 11.0 10.6 5.3 1.8 3.5 3.6 1. 3.4 micrograms per,liter 1 Manuscript received July 26, 1956. - . Contribution from the Department of Northern A fairs and National Resources, Ottawa, Canada. 5 7 0 C A N A D I A N J O U R N A L O F Z O O L O G Y . V O L . 34, 1956 to be 3.4 fxgm. per l i ter . T a b l e II lists c o m p o s i t i o n figures of m i l k f r o m the m u s k ox and other m a m m a l s , as g i v e n b y E s p e a n d S m i t h (2), a n d w i t h a d d i t i o n s b y K i t t s et al. (3), and this w r i t e r . T h e to ta l ca lor ic content of the m u s k - o x m i l k was not d e t e r m i n e d b y b o m b c a l o r i m e t r y , b u t the gross content was es t imated b y c a l c u l a t i o n f r o m the c o m p o s i t i o n values . T h i s was c o m p u t e d to be 657.7 k c a l . per l b . T h e calor ic va lues of 1 g m . of m i l k f r o m species l isted b y K i t t s et al. (3), a long w i t h those of bison and m u s k ox, have been ca lcu la ted a n d are presented i n T a b l e III. These values are based on the gross heats of c o m b u s t i o n of proteins , fats, and carbohydra tes in the report of the F o o d and A g r i c u l t u r e O r g a n i z a t i o n of the U n i t e d N a t i o n s (1). N o correc t ion factor for the loss i n urine has been a p p l i e d to the prote in v a l u e of 5.65 ca l . per g m . T h e fat a n d c a r b o h y d r a t e values of 9.25 a n d 3.95 c a l . per g m . , respect ive ly , have not been corrected as ingested nutr ients , for the coefficients of digest ib i l i t ies of the an imals p r o b a b l y are v a r i a b l e . T A B L E I I C O M P A R I S O N O F T H E C O M P O S I T I O N O F M U S K - O X M I L K W I T H T H A T O F O T H E R M A M M A L S * Species Constituents as percentages of the whole mi lk F a t Prote in Lactose A s h W a t e r T o t a l solids Deer (Hagen, 1 9 5 1 ) 8 . 3 _ _ 1 . 4 7 9 . 6 2 0 . 4 Deer ( K i t t s et al.) 1 0 . 5 9 . 6 3 . 9 1 . 6 . 7 4 . 9 2 5 . 1 Deer ( K i t t s et al.) 1 0 . 5 9 . 0 4 . 7 1 . 3 7 4 . 6 2 5 . 4 Deer ( K i t t s et al.) 1 0 . 2 8 . 1 4 . 5 1 . 6 7 5 . 5 2 4 . 5 Reindeer 2 2 . 5 1 0 . 3 2 . 5 1 . 4 . ' 6 3 . 3 3 6 . 7 M a n 3 . 8 1 . 6 7 . 0 0 . 2 8 7 . 4 1 2 . 6 Horse 1 . 6 2 . 7 ' 6 . 1 0 . 5 8 9 . 0 1 1 . 0 Sheep 6 . 2 •5 .4 4 . 3 0 . 9 8 2 . 9 1 7 . 1 C o w 4 . 4 3 . 8 4 . 9 0 . 7 8 6 . 2 - 1 3 . 8 P i g 7 . 0 6 . 0 4 . 0 0 . 9 8 3 . 0 1 7 . 0 Pronghorn antelope 1 3 . 0 6 . 9 4 . 0 1 . 3 7 5 . 1 2 4 . 9 Water buffalo 1 2 . 0 6 . 0 4 . 0 0 . 9 7 7 . 1 2 2 . 9 . Bison (sample I ) 1 . 8 3 . 7 - 3 . 7 ( ? ) 0 . 9 — 1 3 . 0 (sample I I ) 1 . 7 4 . 2 5 . 7 1 . 0 — 1 3 . 7 M u s k ox 1 1 . 0 5 . 3 3 . 6 1 . 8 7 8 . 4 6 2 1 . 5 * After Espe and Smith, and Kitts et al. T A B L E I I I C A L C U L A T E D C A L O R I C V A L U E ( C A L . / G M . ) M I L K F R O M S E V E R A L S P E C I E S Species Deer sample • Prong- Bison Rein- horn Water Musk 1 2 3 deer Man Horse Sheep Cow Pig antelope buffalo 1 2 ox 1 . 6 6 . 1 . 6 6 1.58 2 .73 0 . 7 0 0 . 5 4 1.04 0 .81 1 .13 1.74 1.60 0 . 5 2 0 .62 1.45 T E N E R : M U S K - O X M I L K 571 Discussion T h e v a l u e s o f t h e c o n s t i t u e n t s f o u n d i n t h e p r e s e n t s a m p l e o f m u s k - o x m i l k m a y h a v e b e e n i n f l u e n c e d b y t h e d e a t h o f t h e a n i m a l p r i o r t o m i l k i n g a n d w a s u n d o u b t e d l y i n f l u e n c e d b y t h e s t a g e o f l a c t a t i o n o f t h e c o w . A s E s p e a n d S m i t h i n d i c a t e , h o w e v e r , g r o s s c o m p o s i t i o n o f m i l k t e n d s t o b e c o m e s t a b l e 12 t o 18 h r . p o s t p a r t u m . T h e v a l u e s o b t a i n e d a r e u s e f u l , t h e r e f o r e , a s a b a s i s o f c o m p a r i s o n o f m u s k - o x m i l k w i t h t h e m i l k o f o t h e r a n i m a l s . M u s k - o x m i l k m o s t c l o s e l y r e s e m b l e s t h a t o f w a t e r b u f f a l o i n i t s c o n s t i t u e n t p r o p o r t i o n s a n d e n e r g y d i s t r i b u t i o n . S u r p r i s i n g l y e n o u g h , t h o s e o f t h e b i s o n , as c a l c u l a t e d f r o m S h u t t ' s (4) d a t a , a r e i n n o w a y s i m i l a r . I t m a y b e t h a t t h e f a t c o n t e n t o f m u s k - o x m i l k is h i g h e r t h a n t h a t o f t h e m i l k o f b i s o n b e c a u s e m u s k - o x c a l v e s n e e d a h i g h l y n u t r i t i o u s d i e t t o c o p e w i t h a v e r y r i g o r o u s e n v i r o n m e n t . T h e v i t a m i n B12 c o n t e n t o f m u s k - o x m i l k i s s o m e w h a t s i m i l a r t o t h a t f o u n d i n t h e m i l k o f d o m e s t i c c a t t l e . T h e m i l k o f r e i n d e e r , t h e o t h e r a r c t i c u n g u l a t e c o n s i d e r e d i n T a b l e s I I a n d I I I , h a s t w i c e t h e f a t a n d p r o t e i n c o n t e n t a n d t w o - t h i r d s t h e l a c t o s e c o n t e n t o f m u s k - o x m i l k . T h i s h i g h e r c o n t e n t o f t h e t w o c o n s t i t u e n t s i s m o s t l i k e l y a n i n h e r i t e d c h a r a c t e r i s t i c o f t h e s p e c i e s a n d m a y b e a s s o c i a t e d w i t h i t s e a r l i e r a g e o f s e x u a l m a t u r i t y a n d m o r e p r e c o c i o u s d e v e l o p m e n t o f t h e y o u n g , a s c o m p a r e d w i t h m u s k o x e n . O f a l l a r c t i c u n g u l a t e s , m u s k o x e n e x i s t u n d e r s o m e o f t h e m o s t r i g o r o u s c o n d i t i o n s ( T e n e r (5) ) . C a l v e s a r e b o r n i n a t u n d r a w i n t e r e n v i r o n m e n t a n d m a y b e n u r s e d a s l o n g a s a m o n t h b e f o r e s p r i n g v e g e t a t i o n a p p e a r s . T h e c o w f r o m w h i c h t h e p r e s e n t m i l k s a m p l e w a s o b t a i n e d w a s i n g o o d c o n d i t i o n w i t h a n a b u n d a n c e o f v i s c e r a l a n d b a c k f a t . T h e r e d i d n o t a p p e a r t o h a v e b e e n a n y s t r a i n o f g e s t a t i o n o n i t , as p o s t u l a t e d f o r d e e r b y K i t t s et al. (3). Acknowledgments T h e w r i t e r is i n d e b t e d t o D r . R . R . R i e l a n d D r . J . A . C a m p b e l l f o r t h e i r a n a l y s e s o f t h e m u s k - o x m i l k s a m p l e . References 1. ANONYMOUS. Energy-yielding components of food and computation of calorie values. Food and Agriculture Organization of the United Nations. Washington, U .S .A. 1947. 2. ESPE, W . and SMITH, V. R. Secretion of milk. 4th ed. Iowa State College Press, Ames, Iowa. 1952. 3. KITTS, W. D . , COWAN, I. M c T . , BANDY, J., and WOOD, A. J . The immediate post-natal growth in the Columbian black-tailed deer in relation to the composition of the milk of the doe. J. Wildlife Management, 20(2) : 212-214. 1956. 4. SHUTT, F. T . Milk of the American Buffalo. Analyst, 56(676) : 454. 1932. 5. TENER, J . S. Facts about Canadian musk-oxen. Trans. 19th North A m . Wildlife Conf., March 8, 9, 10. 1954. pp. 504-510. R e p r i n t e d f r o m C a n a d i a n J o u r n a l o f Z o o l o g y , V o l . 36, N o . hi 529-532, 1958„ O N S O M E H E L M I N T H P A R A S I T E S C O L L E C T E D F R O M T H E M U S K O X ( O V I B O S M O S C H A T U S ) I N T H E T H E L O N G A M E S A N C T U A R Y , N O R T H W E S T T E R R I T O R I E S b y H a r o l d C „ G i b b s a n d J o h n S . T e n e r C a n a d i a n W i l d l i f e S e r v i c e 1 A b s t r a c t T h r e e s p e c i e s o f n e m a t o d e s a n d t h r e e s p e c i e s o f c e s t o d e s a r e r e p o r t e d f r o m O v i b o s m o s c h a t u s t a k e n i n t h e T h e l o n G a m e S a n c t u a r y , N . W . T , I n t r o d u c t i o n D u r i n g t h e s u m m e r o f 1957 i n t h e c o u r s e o f t h e C a n a d i a n W i l d l i f e S e r v i c e s t u d y o n m u s k o x e n , t h e a u t h o r s h a d t h e o p p o r t u n i t y o f c o l l e c t i n g s o m e h e l m i n t h p a r a s i t e s f r o m t h r e e a d u l t m a l e s o f t h i s s p e c i e s t a k e n u n d e r p e r m i t i n t h e T h e l o n G a m e S a n c t u a r y , N . W . T . P r o b a b l y t h e f i r s t r e p o r t o f ' p a r a s i t e s f r o m m u s k o x w a s t h a t o f F i e l d e n (6), w h o i n 1 8 7 7 " r e p o r t e d t h e f i n d i n g o f t w o s p e c i e s o f h e l m i n t h s f r o m a n i m a l s t a k e n i n e a s t G r e e n -l a n d . T h e s e w e r e T a e n i a s p . a n d F i l a r i a s p . L a t e r , J e n s e n (9) i n 190h f o u n d " " a t a p e w o r m i n t h e b l a d d e r p h a s e " i n t h e l i v e r o f a n a n i m a l t a k e n a t H u r r y I n l e t , G r e e n l a n d . O n t h e N o r t h A m e r i c a n c o n t i n e n t , D i k m a n s (3) i n 1939 l i s t e d f o u r s p e c i e s o f h e l m i n t h s f r o m t h e m u s k o x , t h r e e n e m a t o d e s a n d o n e c e s t o d e , b u t m a d e n o r e f e r e n c e t o t h e l o c a l i t y f r o m w h i c h t h e a n i m a l s w e r e o b t a i n e d . M o r e r e c e n t l y T e n e r (17) r e p o r t e d f i n d i n g a s p e c i e s o f c e s t o d e i n a n a n i m a l t a k e n o n E l l e s m e r e I s l a n d , N . W . T . I n v i e w o f t h e s c a r c i t y o f l i t e r a t u r e o n t h e p a r a -s i t e s o f t h i s h o s t s p e c i e s i t w a s f e l t t h a t t h e a u t h o r s ' f i n d -i n g s s h o u l d b e p u b l i s h e d „ L i s t o f P a r a s i t e s N E M A T O D A M E T A S T R O N G Y L I D A E L E I P E R , 1908 D i c t y o c a u l u s v i v i p a r u s ( B l o c h , 1782) T h i s p a r a s i t e w a s f o u n d i n t h e b r o n c h i o l e s o f t h e l u n g s o f a l l t h r e e a n i m a l s . T h e r e w a s a f a i r l y h e a v y i n f e s t a -t i o n r e s u l t i n g i n a n o d u l a r f i b r o s i s a t t h e m a r g i n s o f t h e d i a p h r a g m a t i c l o b e s . P o r t i o n s o f t h e l u n g s u r f a c e s h o w e d r a i s e d e m p h y s e m a t o u s a r e a s c a u s e d b y a i r t r a p p e d w h e n t h e b r o n c h i o l e s w e r e b l o c k e d b y w o r m s a n d d e b r i s . M i c r o s c o p i c e x a m i n a t i o n r e v e a l e d c h a n g e s c h a r a c -t e r i s t i c o f v e r m i n o u s b r o n c h i t i s . T h i s I s t h e f i r s t r e c o r d o f t h e p a r a s i t e f r o m t h i s h o s t i n t h e w i l d s t a t e , a l t h o u g h I t ' h a s b e e n r e p o r t e d b y D u r r e l l a n d B o l t o n ( 5 ) f r o m a c a l f i n V e r m o n t . 2 T R I C H O S T . R O N G Y L I D A E L E I P E R , 1912s T R I C H O S T R O N G Y L I N A E L E I P E R , 1909 N e m a t o d i r e l l a l o n g i s p i c u l a t a ( R o m a n o v i t c h , 1915) T h i s n e m a t o d e w a s f o u n d i n t h e d u o d e n u m a n d a n t e r i o r j e j u n u m o f o n e a n i m a l ' . I t ' i s c h a r a c t e r i z e d b y t h e p r e s e n c e o f v e r y l o n g s p i c u l e s i n t h e m a l e a n d n o n - d e v e l o p m e n t o f t h e a n -t e r i o r h o r n o f t h e u t e r u s i n t h e f e m a l e „ W h e n f r e s h t h e s e w o r m s p r e s e n t a r e d d i s h a p p e a r a n c e a n d i n t h e f e m a l e t h e w h i t e c o i l s o f t h e u t e r u s a r e e a s i l y s e e n . T h e r e w a s s o m e e v i d e n c e ' o f p a r a s i t i c e n t e r i t i s i n t h e : - d u o d e n u m o f t h e a n i m a l i n f e s t e d . T h e r e w e r e p e t e c h i a l h a e m o r r h a g e s , s o m e ' d e n u d i n g o f t h e m u c o s a , a n d a q u a n t i t y o f • m u c u s i n t h e l u m e n . I n a d d i t i o n r e d d i s h p l a q u e - l i k e a r e a s w e r e o b s e r v e d o n t h e w a l l s o f t h e d u o d e n u m i n t h e a r e a w h e r e t h e s e w o r m s w e r e f o u n d . M i c r o s c o p i c e x a m i n a t i o n o f t h e s e a r e a s r e v e a l e d t h e p r e s e n c e o f a g r a n u l o m a t o u s - t y p e l e s i o n o f t h e s u b m u c o s a . T h e r e w a s n o e v i d e n c e o f a c i d - f a s t b a c i l l i a n d i t i s d e b a t a b l e w h e t h e r t h i s l e s i o n w a s t h e r e s u l t o f p a r a s i t i s m . T h i s i s t h e f i r s t r e c o r d o f t h e p a r a s i t e f r o m t h i s h o s t . I t h a d p r e v i o u s l y b e e n r e p o r t e d b y R o m a n o v i t c h (12) f r o m r e i n d e e r , . a n d f r o m m o o s e a n d p r o n g h o r n a n t e l o p e b y D i k -m a n s ( 3 ) . O s t e r t a g i a c i r c u m c i n c t a ( S t a d e l m a n , l89 1 +) T h i s p a r a s i t e w a s f o u n d a t t h e p y l o r i c e n d o f t h e a b b m a s u m i n a l l t h r e e " a n i m a l s . I n o n e a n i m a l t h e p y l o r u s w a s t h i c k l y c o v e r e d b y n u m e r o u s w o r m s b u t " t h e y a p p e a r e d t o c a u s e l i t t l e d a m a g e . I n t h e o t h e r a n i m a l s o n l y a f e w i n d i v i d u a l s w e r e s e e n . T h i s s p e c i e s w a s p r e v i o u s l y r e p o r t e d f r o m t h e m u s k o x " b y D i k m a n s ( 3 ) , C E S T O D A A N O P L O C E P H A L I D A E . C H O L O D K O W S K Y , 1902 M o n i e z i a e x p a n s a ( R u d o l p h i , 1805) A n u m b e r o f t h e s e w o r m s w e r e o b t a i n e d f r o m t h e i l e u m o f a l l t h r e e a n i m a l s . T h e r e " i s s t i l l m u c h c o n f l i c t i n g e v i d e n c e o n t h e p a t h o l o g i c a l s i g n i f i c a n c e o f t h e s e " w o r m s . T h e a n i m a l s e x a m i n e d d i d n o t a p p e a r tx> b e a f f e c t e d . " T e n e r (17) p r e v i o u s l y r e p o r t e d ' f i n d i n g a n u n -i d e n t i f i e d s p e c i e s " o f t h i s g e n u s I n " a 2 - y e a r - o l d b u l l h e e x a m i n e d o n E l l e s m e r e I s l a n d , N . W . T , 3 T A E N I I D A E H A L D E M A N , l 8 £ L C y s t i c e r c u s t e n u i c o l l i s R u d o l p h ! , 1810 - ' . T h i s , l a r v a l f o r m o f T a e n i a h y d a t i g e n a P a l l a s , 1776 w a s f o u n d i n a n u m b e r o f l o c a t i o n s o n a l l t h r e e a n i m a l s . T h e c y s t s , b o t h ' v i a b l e a n d c a l c i f i e d . , w e r e ' f o u n d o n t h e s u r f a c e o f t h e l i v e r a s w e l l a s d e e p i n t h e l i v e r t i s s u e . ' S o m e w e r e a l s o f o u n d i n t h e g r e a t e r o m e n t u m , a r i d o n t h e p e r i t o n e u m . ' C h o q u e t t e e t a l . (2) h a v e ' d r a w n " a t t e n t i o n ' t o " t h e f a c t t h a t d e v e l o p m e n t o f t h e ' c y s t s ' d e e p " i n " t h e " l i v e r t i s s u e i s d i f f e r e n t f r o m t h a t s e e n I n d o m e s t i c s h e e p w h e r e , a l t h o u g h c y s t s m a y b e s e e n o c -c a s i o n a l l y o n t h e s u r f a c e , t h e y a r e n e v e r f o u n d d e e p i n t h e t i s s u e . T h i s p a r a s i t e , w h i c h i s c o m m o n ' i n " n o r t h e r n h e r b i -v o r e s , w a s p r e v i o u s l y d e s c r i b e d f r o m m u s k o x e n b y D i k m a n s (3). E c h i n o c o c c u s g r a n u l o s u s ( B a t s c h , 1786) A c y s t o f t h i s p a r a s i t e w h i c h a p p e a r e d t o b e m u l -t i l o c u l a r a n d s t e r i l e o n g r o s s e x a m i n a t i o n W a s f o u n d i n t h e l u n g s o f o n e a n i m a l . M i c r o s c o p i c ' e x a m i n a t i o n c o n f i r m e d t h e b e l i e f t h a t i t w a s s t e r i l e a s , t h o u g h a ' l a m i n a t e d m e m b r a n e w a s v i s i b l e , t h e r e w a s n o e v i d e n c e " o f s c o l i c e s . T h i s i s t h e f i r s t r e c o r d o f t h e p a r a s i t e i n t h i s h o s t . D i s c u s s i o n T h e h e l m i n t h f a u n a o f t h i s s p e c i e s o f h o s t I s s e e n t o b e t y p i c a l , o f t h a t f o u n d i n n o r t h e r n ' r u m i n a n t s . T h e s e p a r a s i t i c s p e c i e s a p p a r e n t l y e x h i b i t g r e a t r e s i s t a n c e t o t h e e f f e c t s o f " l o w e n v i r o n m e n t a l t e m p e r a t u r e s a s s h o w n b y t h e w o r k o f G r i f f i t h s " ( 8 ) , F u r m a n (7), D i n a b u r g tk), S c h i l l e r ' (Ik), a n d o t h e r s . A l l o f t h e s p e c i e s r e p o r t e d I n t h i s ' s u r v e y " a r e f o u n d i n a n u m b e r o f d i f f e r e n t s p e c i e s o f r u m i n a n t h o s t a n d c e r t a i n l y o c c u r i n a l l o f t h e r u m i n a n t h o s t s f o u n d i n t h e N o r t h w e s t " T e r r i t o r i e s . I t , t h e r e f o r e , a p p e a r s t h a t r e s i s t a n c e t o l o w e n v i r o n m e n t a l t e m p e r a t u r e s c o u p l e d w i t h a v e r s a t i l i t y i n c h o i c e o f h o s t h a v e e n a b l e d t h e s e p a r a s i t e s t o e x p l o i t t h e i r e c o l o g i c a l n i c h e t o t h e f u l l e s t e x t e n t . I n 1957 D u r r e l l a n d B o l t o n (5) c l a i m e d t h a t a f e m a l e m u s k " o x c a l f w h i c h " h a d d i e d o f h a e m o n c h o s i s o n a f a r m i n V e r m o n t , U . S . A . , p r o b a b l y b e c a m e i n f e c t e d i n i t s n a t i v e e n v i r o n m e n t , w h i c h . w a s t h e - T h e l o n " G a m e S a n c t u a r y . I t i s f e l t t h a t t h i s a s s u m p t i o n I s e r r o r i e . o u s ' . ' . " I t h a s b e e n s h o w n b y G r i f f i t h s (8), S h o r b (15), K a t e s (10). S a r l e s (13)5 a r i d r e c e n t l y B e l l e (1) t h a t t h e f r e e - l i v i n g s t a g e s o f H a e m o n c h u s c o n t d r t u s a r e n o t v e r y r e s i s t a n t t o t e m p e r a t u r e s b e l o w f r e e z i n g . " I t i s u n l i k e l y , t h e r e f o r e , t h a t t h i s p a r a s i t e c o u l d s u r v i v e t h e s e v e r e W i n t e r c o n -d i t i o n s p r e s e n t i n t h e T h e l o n G a m e S a n c t u a r y . F u r t h e r -m o r e , t h i s p a r a s i t e h a s n e v e r b e e n r e p o r t e d b e f o r e f r o m n o r t h e r n r u m i n a n t s . T h e m u s k o x i n q u e s t i o n h a d b e e n p u t o n t o p a s t u r e i n t h e s p r i n g w i t h d o m e s t i c c a t t l e a n d g o a t s w h i c h " w e r e s a i d t o h a v e b e e n n e g a t i v e f o r p a r a s i t e s " , a n d h a d b e e n t r e a t e d w i t h p h e n o t h i a z i n e a s a ' f u r t h e r p r e c a u t i o n a r y m e a s u r e . T h e d o m e s t i c c a t t l e w e r e l a t e r f o u n d i n f e c t e d w i t h s t o m a c h w o r m s W h i c h t h e a u t h o r s c o n s i d e r e d t o h a v e b e e n c o n t r a c t e d f r o m t h e m u s k ' o x . H o w e v e r , p r o b a b l y t h e r e v e r s e w a s t r u e a s t h e s t r a i n o f p a r a -s i t e . f o u n d w a s t h e b o v i n e s t r a i n , H . p l a c e i . I t a p p e a r s f r o m s e r o l o g i c a l f i n d i n g s b y M o o d y (11) t h a t t h e m u s k o x i s m o r e c l o s e l y r e l a t e d t o g o a t s t h a n t o c a t t l e . I t i s a u n i v e r s a l l y h e l d p r e c e p t t h a t t h e e s t a b l i s h m e n t o f " a p a r a s i t e i n a n e w o r u n u s u a l h o s t u s u a l l y e l i c i t s a s e v e r e p a t h o l o g i c a l ~ r e s p o n s e . W h a t p r o b a b l y h a p p e n e d , t h e r e f o r e , w a s t h a t t h e m u s k o x c o n -t r a c t e d i t s f a t a l i n f e c t i o n f r o m t h e c a t t l e w h e n t h e t w o s p e c i e s w e r e p u t t o g e t h e r o n p a s t u r e i n t h e s p r i n g . h e l m i n t h p a r a s i t e s r e c o r d e d f r o m m u s k o x e n c o l -l e c t e d i n t h e i r n a t u r a l h a b i t a t L o c a t i o n i n h o s t L o c a l i t y A u t h o r C h e c k l i s t o f P a r a s i t e D i c t y o c a u l u s v i v i p a r u s N e m a t o d i r e l l a l o n g i s p i c u l a t a O s t e r t a g i a " c i r c u m c i n c t a . 0 & m o s s i  0 P o c c i d e h t a l i s F i i a r i a s p . ' M o n i e z i a s p „ . M . e x p a n s a T a e n i a s p . ' ' B l a d d e r p h a s e o f t a p e w o r m C y s t i c e r c u s t e n u i c o l l i s E c h i n o c o c c u s e r a n u l o s u s L u n g s D u o d e n u m , j e j u n u m P y l o r u s o f a b o m a s u m A b o m a s u m . A b o m a s u m I l e u m I l e u m L i v e r L i v e r , " o m e n -t u m , p e r i -t o n e u m L u n g s T h e l o n T h e l o n N . A m e r i c a , T h e l o n N . A m e r i c a N . A m e r i c a E . G r e e n l a n d E l l e s m e r e I s l a n d T h e l o n E . G r e e n l a n d H u r r y I n l e t T h e l o n , ' ' N o A m e r i c a T h e l o n P r e s e n t s t u d y P r e s e n t s t u d y D i k m a n s (3)» p r e s e n t s t u d y D i k m a n s (3) D i k m a n s (3) F i e l d e n (6) T e n e r (17) " P r e s e n t s t u d y F i e l d e n (6) J e n s e n (9) P r e s e n t s t u d y , D i k m a n s (3) P r e s e n t s t u d y A c k n o w l e d g m e n t " T h e w r i t e r s a r e g r a t e f u l t o D r . A . N . C o r n e r , A n i m a l D i s e a s e s R e s e a r c h I n s t i t u t e , H u l l , Q u e b e c , f o r m a k i n g t h e h i s t o -p a t h o l o g i c a l s t u d i e s . 5 R e f e r e n c e s 1. B E L L E , ' E - . A . P e r s o n a l - c o m m u n i c a t i o n (1957). 2. C H O Q U E T T - E j ' L . P . E . , W H I T T E N , L . K . , R A N K I N , G . , a n d S E A L , C M . N o t e s o n p a r a s i t e s f o u n d i n " r e i n d e e r ( R a n g i f e r t a r a n d u s ) i n C a n a d a . C a n . J . C o m p . M e d . 21, 199-203 (1957)o • 3• D I K M A N S , G . H e l m i n t h p a r a s i t e s ' o f N o r t h ' A m e r i c a n s e m i -d o m e s t i c a t e d a n d w i l d r u m i n a n t s . P r o c . H e l m i n t h o l . S o c „ W a s h . 6, 97-101 (1939). k. D I N A B U R G , A . G . T h e e f f e c t " o f l o w o u t d o o r t e m p e r a t u r e s o n t h e f r e e - l i v i n g s t a g e s o f • s o m e c o m m o n n e m a t o d e s o f s h e e p . A m . J . V e t . R e s e a r c h , 6,' 257-263 (19*4-5). 5. D U R R E L L , " W . B . a n d ' B O L T O N , " W . D . P a r a s i t o s i s i n a m u s k -o x . J , A m . V e t „ M