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Foraging ecology and nutrition of Stone’s sheep Seip, Dale R. 1983

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FORAGING ECOLOGY AND NUTRITION OF STONE'S SHEEP  by DALE ROY B.Sc,  SEIP  U n i v e r s i t y of Western O n t a r i o ,  1976  M . S c , Simon F r a s e r U n i v e r s i t y , 1980  A THESIS SUBMITTED IN PARTIAL FULFILMENT OF THE  REQUIREMENTS  FOR THE DEGREE OF  DOCTOR OF PHILOSOPHY in THE  FACULTY OF GRADUATE STUDIES (Department  we a c c e p t to  THE  this  of F o r e s t r y )  t h e s i s as conforming  the required  standard  UNIVERSITY OF BRITISH April ©  D.R.  1983  Seip,  1983  COLUMBIA  DE-6  In p r e s e n t i n g  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  requirements f o r an advanced degree at the  the  University  o f B r i t i s h Columbia, I agree t h a t the L i b r a r y s h a l l make it  f r e e l y a v a i l a b l e f o r reference  and  study.  I  further  agree t h a t p e r m i s s i o n f o r e x t e n s i v e copying o f t h i s t h e s i s f o r s c h o l a r l y purposes may department or by h i s or her  be  granted by  the head o f  representatives.  my  It is  understood t h a t copying or p u b l i c a t i o n o f 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  permission.  Department of The U n i v e r s i t y of B r i t i s h Columbia 1956 Main Mall Vancouver, Canada V6T 1Y3 Date  (3/81)  written  ABSTRACT T h i s study compared the f o r a g i n g behaviour n u t r i t i o n of Stone's sheep (Ovis d a l l i  and  s t o n e i ) which had  access to burned range to t h a t of sheep on unburned range throughout  the year.  In w i n t e r , sheep were r e s t r i c t e d  areas with l e s s than 25-30 cm  of snow.  For most sheep  t h i s meant windswept, a l p i n e r i d g e s , but one p o p u l a t i o n used a burned, s u b a l p i n e s l o p e . pressure was  small Grazing  h i g h on these r e s t r i c t e d winter  ranges,  p a r t i c u l a r l y d u r i n g a severe w i n t e r , r e s u l t i n g j  of a l l the forage from a l p i n e range, and poor q u a l i t y  reflected  i n low  DAPA l e v e l s and high P r o t o s t r o n q y l u s  i n removal  l e a v i n g only very  forage on the s u b a l p i n e range.  winter n u t r i t i o n was  to  The  poor  f e c a l n i t r o g e n and counts.  In s p r i n g , sheep used e i t h e r n a t u r a l or f i r e - i n d u c e d s u b a l p i n e c l e a r i n g s to o b t a i n e a r l y new Forage q u a n t i t y was b i t i n g r a t e and  much lower  on unburned ranges,  behaviour domestic  but  f o r a g i n g time were the same as on burned  ranges with h i g h forage biomass. forage and  p l a n t growth.  Q u a l i t y of a v a i l a b l e  food intake were a l s o s i m i l a r .  The  foraging  of Stone's sheep appeared to be s i m i l a r sheep i n that intake r a t e was  on grass l e n g t h r a t h e r than  to  p r i m a r i l y dependent  forage d e n s i t y .  Sheep moved t o h i g h e r progressed quality  which p r o v i d e d  alpine forage.  summer a p p a r e n t l y Grasses  them w i t h a c c e s s  Regular  satisfied  important  the year  their  although  to the higher  use of m i n e r a l  and s e d g e s were t h e most  throughout  sodium  licks in  requirement.  important  foods  f o r b s a n d browse were  i n t h e summer.  Adult low  e l e v a t i o n s as the season  m o r t a l i t y r a t e s were l o w .  f o l l o w i n g severe  nutrition.  Lamb p r o d u c t i o n  w i n t e r s , presumably  An e x p l a n a t i o n  b a s e d on d e n s i t y - d e p e n d e n t  f o r changes selective  was  due t o p o o r  i n lamb  production  f e e d i n g was  developed. Burned  r a n g e s were o f l i m i t e d  because they not  provide  summer. better  superior  Horn  ranges.  sheep  range, d i d  s p r i n g range a n d were n o t u s e d i n  g r o w t h , however, a p p e a r e d  on b u r n e d  seasonal  t o Stone's  were u s u a l l y u n a v a i l a b l e a s w i n t e r  t o be  slightly  ranges.  A model o f n u t r i e n t i n t a k e the  value  i s developed  p a t t e r n of n u t r i t i o n  to investigate  on b u r n e d and u n b u r n e d  TABLE OF CONTENTS PAGE Abstract  i i  Table of Contents List  of T a b l e s  List  of F i g u r e s  List  of Appendices  i v  x  i  i  v  i  i i xviii  Acknowledgements  xix  1  Introduction Stone's sheep  3  N u t r i t i o n of ruminants  4  Food s e l e c t i v i t y  6  Intake r a t e  7  Population  c o n d i t i o n and p o p u l a t i o n  dynamics ..  9  Study area  11  Methods  17  Range use p a t t e r n s  and group composition  counts  17  Range a n a l y s i s  18  Soil analysis Fecal analysis  . 19 20  TABLE OF CONTENTS PAGE Food h a b i t s  20  Parasitology  21  Foraging  21  behaviour  C a p t u r i n g and measurements  Results  -  Range use p a t t e r n s  ....  24  26 26  Winter range  26  S p r i n g range  33  A l t i t u d i n a l m i g r a t i o n t o summer range .... 37 Fall  range  Spatial  s e p a r a t i o n of sexes  39 42  Forage p r o d u c t i o n and biomass on Stone's sheep ranges  43  P a t t e r n of p r o d u c t i o n  43  Winter range  48  Forage q u a l i t y  51  Winter forage  51  Spring-summer forage  56  Food h a b i t s  65  Winter food h a b i t s  69  S p r i n g food h a b i t s  71  Summer food h a b i t s  72  Fall  72  food h a b i t s  Nutritional  i n d i c e s of the sheep  73  vi  TABLE OF CONTENTS PAGE Food s e l e c t i v i t y S e l e c t i o n of s p e c i e s  9  7  9 9  Species  selected against  7  Species  selected for  80  S e l e c t i o n of graminoids versus  forbs  S e l e c t i o n of s u p e r i o r q u a l i t y food  S o i l mineral  80 82 84  Mineral n u t r i t i o n concentrations  Forage mineral  concentrations  Behaviour at mineral  licks  84 86 88 89  Mineral l i c k s Foraging  7  91  behaviour  91  B i t i n g rate Daily pattern  91  Sex  91  and age d i f f e r e n c e s  Seasonal p a t t e r n Foraging  92 92  time  Length and number of f o r a g i n g bouts  99  Parasitology  102  Horn growth of rams  104  Population  107  parameters  P o p u l a t i o n numbers  107  Lamb and y e a r l i n g counts  109 I l l  Survival rates Group s i z e  •  113  TABLE OF CONTENTS PAGE H 5  Discussion Seasonal p a t t e r n of n u t r i t i o n  115  A model of food and energy intake f o r mountain  115  sheep  I m p l i c a t i o n s of the model  119  Protein n u t r i t i o n  126  Summary of seasonal  n u t r i t i o n patterns . . . 126 130  S e l e c t i v e feeding  130  Range s e l e c t i o n S e l e c t i o n of forage  species  132  S e l e c t i o n of s u p e r i o r q u a l i t y food  133  S e l e c t i n g a mixed d i e t  134  Sexual d i f f e r e n c e s i n s e l e c t i v i t y  134  Summary of food s e l e c t i v i t y  136  Intake r a t e  137  Animal c o n d i t i o n and growth  146  Population  148  dynamics  Management of Stone's sheep  155  Conclusions  160  References C i t e d  163  Appendices  v i i i  L I S T OF  TABLES  PAGE 1.  2.  Average  climatic  d a t a f o r Muncho  British  Columbia  (1955-1978)  sheep  northeastern  spring British  ranges  several  (May-June) i n  Columbia  (1980-1982) ....  S p e c i e s c o m p o s i t i o n (% c o v e r ) of Stone's  sheep  northeastern  4.  14  S p e c i e s c o m p o s i t i o n (% c o v e r ) o f Stone's  3.  Lake,  I_n v i t r o  summer r a n g e s British  ranges  several  (June-July) in  Columbia  (1980-1982) ....  dry matter d i g e s t i b i l i t y  g r a m i n o i d s and  forbs  from S t o n e ' s  in northeastern  British  (%)  Quality sheep  sheep  Columbia  northeastern  6.  Food  55  analysis  ranges  41  of  ( 1980-1 982)  5.  36  of browse s p e c i e s on  in spring British  and  Stone's  summer i n  Columbia  (1980-1982) ....  h a b i t s o f S t o n e ' s s h e e p on British  62  unburned  range  in northeastern  Columbia  1982)  d e t e r m i n e d by rumen a n a l y s i s  (1980-  66  ix LIST OF TABLES PAGE 7.  Food h a b i t s of Stone's sheep on  subalpine  burned range i n n o r t h e a s t e r n B r i t i s h  Columbia  (1980-1982) determined by f e c a l a n a l y s i s . . . . . . .  8.  Food h a b i t s of Stone's sheep on  unburned  range i n n o r t h e a s t e r n B r i t i s h Columbia  9.  analysis  68  Seasonal changes  ash content of  Stone's sheep on burned and unburned in n o r t h e a s t e r n  10.  (1980-  1982) determined by f e c a l  in fecal  B r i t i s h Columbia  ranges  (1980-1982)...  of Stone's sheep compared to  a v a i l a b i l i t y on the range  81  M i n e r a l c o n c e n t r a t i o n s and pH of s o i l s and mineral  12.  l i c k s i n the Toad R i v e r area  Mineral concentrations  i n forages  Columbia  85  from  Stone's sheep ranges i n northeastern  British  (1980-1982) compared to requirements  of domestic sheep  13.  74  P r o p o r t i o n of forbs versus graminoids i n the diet  11.  67  Biting  r a t e of Stone's sheep ewes under  87  LIST OF TABLES PAGE different  (April-June)... 93  range c h a r a c t e r i s t i c s  Time budget and c a l c u l a t e d b i t e s / d a y f o r Stone's sheep ewes and y e a r l i n g s (FebruaryMay).  94  Time budget and c a l c u l a t e d b i t e s / d a y f o r 95  Stone's sheep rams (February-May)  P r o t o s t r o n g y l u s l a r v a e counts i n feces of Stone's sheep on burned and unburned northeastern B r i t i s h  Columbia  range i n  (1982)....  103  Maximum d a i l y count of sheep on F e r t i l i z e r • Mountain each month  (1980-1982)  108  Number of sheep u s i n g C h u r c h i l l mine l i c k and adjacent  areas i n summer ( 1980-1982)  110  Lamb/ewe and yearling/ewe counts of Stone's sheep on F e r t i l i z e r Mountain and a t the C h u r c h i l l mine ( 1980-1982).  112  D i g e s t i b l e energy requirements of sheep under different physiological conditions  116  xi LIST OF TABLES PAGE 21.  Protein a v a i l a b i l i t y  i n forage on  Stone's  sheep ranges compared t o p r o t e i n requirements 128  of domestic sheep  22.  Estimated f o r a g i n g ewe  in different  intake  23.  time of a Stone's  sheep  seasons assuming a constant 141  rate  Forage a v a i l a b i l i t y  of s e v e r a l Stone's sheep  ranges compared t o e s t i m a t e d sheep requirements  144  xii  L I S T OF  FIGURES  PAGE 1.  L o c a t i o n and map  2.  Windswept, a l p i n e w i n t e r area  3.  (February  Burned,  of the study  Fertilizer  5.  Typical (May  6.  of high  (Fertilizer  snowfall 29  range  Mountain  ( J a n u a r y - M a r c h ) on i n a year  of h i g h  ( 1 982).  unburned  32  s p r i n g range  i n Yedhe  valley  1982)  Burned,  3  subalpine  Mountain  7.  range  1 982),  Use o f w i n t e r  snowfall  i n t h e Yedhe 27  winter  Mountain) i n a year  4.  range  12  1982).  subalpine  (February  area  Elevation  (May  Toad  1982)  .  o f r a n g e u s e (mode  Stone's sheep Columbia  s p r i n g r a n g e on  in northeastern  ( 1 980-1982)  4  35  ± r a n g e ) by British  t h r o u g h o u t t h e year.  38  xiii  LIST OF FIGURES PAGE 8.  9.  R e l a t i o n s h i p between  (X~ ± 95% C . I . ) and r a n g e  sheep  i n s p r i n g a n d summer  northeastern  British  sheep  Columbia  R e l a t i o n s h i p between mean t i l l e r  sheep,  weight  subalpine,  of grasses  in  (1980-1982)...  Boundary  British  on S t o n e ' s 45  (X ±  sheep  Columbia  ranges  (1980-1982)...  47  between h e a v i l y g r a z e d a r e a a n d  snow-covered,ungrazed winter  44  l e n g t h and  s p r i n g ranges  d e v i a t i o n ) on S t o n e ' s  northeastern  (X ±  ranges  Seasonal p a t t e r n of f o r b p r o d u c t i o n standard  13.  40  d e v i a t i o n ) on S t o n e ' s  mean t i l l e r  12.  u s e by S t o n e ' s  Seasonal p a t t e r n of graminoid p r o d u c t i o n  in  11.  l e n g t h o f new  grass  standard  10.  tiller  range  area  on s u b a l p i n e  ( F e r t i l i z e r Mountain  1982)  50  S e a s o n a l p a t t e r n o f ADF c o n c e n t r a t i o n s i n graminoids Stone's Columbia  (X ± 90% C . I . ) on  sheep  ranges  ( 1980-1982).  different  i n northeastern  British 52  xiv LIST OF FIGURES PAGE 14.  Seasonal p a t t e r n of crude p r o t e i n c o n c e n t r a t i o n s i n graminoids (X ± 90% C.I.) on d i f f e r e n t  Stone's sheep ranges i n  n o r t h e a s t e r n B r i t i s h Columbia  15.  (1980-1982)  Seasonal p a t t e r n of l i g n i n c o n c e n t r a t i o n s i n graminoids (X ± 90% C.I.) on  different  Stone's sheep ranges i n n o r t h e a s t e r n Columbia  16.  British  ( 1980-1 982)  54  Seasonal p a t t e r n of ADF c o n c e n t r a t i o n s i n forbs  (X ± 90% C.I.) on d i f f e r e n t  sheep ranges i n n o r t h e a s t e r n  Stone's  British  Columbia  ( 1980-1982)  17.  53  57  Seasonal p a t t e r n s of crude p r o t e i n c o n c e n t r a t i o n s i n f o r b s (X ± 90% C.I.) on different  Stone's sheep ranges i n  northeastern  18.  B r i t i s h Columbia  (1980-1982)  58  Seasonal p a t t e r n of l i g n i n c o n c e n t r a t i o n s i n forbs  (X ± 90% C.I.) on d i f f e r e n t  Stone's  sheep ranges i n n o r t h e a s t e r n B r i t i s h ( 1980-1982)  Columbia 59  XV  LIST OF FIGURES PAGE 19.  R e l a t i o n s h i p between t i l l e r  l e n g t h and crude  p r o t e i n c o n c e n t r a t i o n s of new grasses on Stone's sheep ranges (May-July) i n n o r t h e a s t e r n B r i t i s h Columbia  20.  60  C a l c u l a t e d values f o r dry matter digestibility different  (DMD) of graminoids on  Stone's sheep ranges i n  northeastern  21.  (1980-1982)  B r i t i s h Columbia  Summary of seasonal  (1980-1982)  63  food h a b i t s f o r Stone's  sheep determined by f e c a l a n a l y s i s on burned and unburned Columbia  22.  ranges i n n o r t h e a s t e r n  British  (1980-1982)  70  Seasonal p a t t e r n of f e c a l p r o t e i n  levels  ( c o r r e c t e d f o r ash content) f o r Stone's on burned and unburned in northeastern  23.  ranges (X.± 95% C.I.)  B r i t i s h Columbia  ( 1 980- 1 982) , ##  75  Seasonal p a t t e r n of DAPA c o n c e n t r a t i o n s f o r Stone's sheep on burned and unburned n o r t h e a s t e r n B r i t i s h Columbia  24.  sheep  range i n  (1980-1982)  R e l a t i o n s h i p between p r o t e i n c o n c e n t r a t i o n s  78  xvi LIST OF  FIGURES PAGE  of  the a v a i l a b l e  f o r a g e and  c o n c e n t r a t i o n s of Stone's to  25.  the f e c a l  sheep  protein  (standardized 83  15% a s h c o n t e n t )  R e l a t i o n s h i p between snow d e p t h percentage of-foraging  and  time spent d i g g i n g  (X 98  ± s t a n d a r d d e v i a t i o n ) by S t o n e ' s s h e e p  26.  Typical ram  daily  time budgets  g r o u p s compared  of Stone's  sheep  to e w e / y e a r l i n g groups i n 100  M a r c h and May  27.  Comparison  of annual horn  Stone's sheep range  28.  unburned  in northeastern  British 105  ( 1980-1982)..  Comparison  of horn  lengths  from t i p t o  annulus of Stone's  sheep  rams s h o t on  range  range  (X ± 95% C.I.)  and  unburned  northeastern  29.  rams on b u r n e d v e r s u s  CR" ± 95% C.I.)  Columbia  increments of  B r i t i s h Columbia  burned in  (1980-1982).  106  R e l a t i o n s h i p between d i g e s t i b i l i t y o f t h e f o o d and digestive  the d a i l y capacity  intake  o f sheep when  is limiting  118  xvii LIST OF FIGURES PAGE  30.  R e l a t i o n s h i p between d i g e s t i b i l i t y  of the  food and the model's p r e d i c t i o n of maximum 120  p o s s i b l e d a i l y energy intake of sheep  31.  Seasonal p a t t e r n of d a i l y energy intake and energy requirements of a 50 kg ewe  predicted 122  by the model  32.  R e l a t i o n s h i p between body weight of sheep and the model's p r e d i c t i o n of minimum adequate forage d i g e s t i b i l i t y maintenance  33;  adequate to meet 127  requirements  The r e l a t i o n s h i p ^ b e t w e e n  d a i l y energy  intake  of ewes i n winter and p r e d i c t e d values f o r p e r i - n a t a l lamb m o r t a l i t y and summer lamb/ewe ratio  ( 2 - y e a r - o l d and o l d e r ewes).  150  xviii  LIST OF APPENDICES  I.  B i r d s and mammals s i g h t e d  i n the Toad  River  area .  II.  Body weights and measurements of Stone's sheep  III.  The e f f e c t of burning and f e r t i l i z a t i o n Stone's sheep ranges  on  xix  ACKNOWLEDGEMENTS Dr. Fred Bunnell i n i t i a t e d t h i s p r o j e c t and p r o v i d e d guidance and support  throughout.  Drs. M. P i t t ,  J . Kimmins, A. S i n c l a i r , and L. Larson  were the other  members of my a d v i s o r y committee. L e s l i e Gilmore, Derocher p r o v i d e d  Robert D u l f e r , Ray Rasker, and Andy  f i e l d assistance.  Pat M i l l s typed the t h e s i s and Engel Rahs prepared the graphics. Dr. John E l l i o t t  proposed the r e s e a r c h problem and  helped me t o get s t a r t e d . Dr. W. Samuel p r o v i d e d the s e r v i c e s of h i s l a b o r a t o r y f o r the p a r a s i t o l o g y a n a l y s e s and Dr. T.M. B a l l a r d p r o v i d e d the l a b o r a t o r y a n a l y s e s of mineral Members of the Guide O u t f i t t e r s Columbia, p a r t i c u l a r l y Southwick, p r o v i d e d conducting  levels.  A s s o c i a t i o n of B r i t i s h  Ed-and Dave Wiens and B l a i n e  i n f o r m a t i o n and a s s i s t a n c e i n  the study.  Essentially particularly  everyone i n the Toad River  Bruce and Donna Powell  area,  and the P r i c e f a m i l y ,  r e g u l a r l y helped me o u t . My thanks t o a l l of you. Funding f o r t h i s work was p r o v i d e d by the Canadian N a t i o n a l Sportsmen's Fund, the G u i d e - O u t f i t t e r s A s s o c i a t i o n of B r i t i s h Columbia, the Foundation  f o r North  American Wild Sheep, and the A r c t i c and A l p i n e Research Committee  (UBC).  1  INTRODUCTION The  concept  implies  that  of an  the  to death  forego  spp.)  eat  around, are  food, cannot  grass.  i t may  food  Because t h e r e  seem s t r a n g e  limited.  standing  c r o p of g r a s s by  deer  1976,  (Odocoileus  spp.)  last  standing willow But  we  t h e end  50  of  Brink  with winter  1976)  and  (Ramsay  1980)  o r by  and  can  Wishart  known f o r o t h e r  1979).  Yet  grass  t h a t mountain winter t o 80%  1978).  sheep  ranges, of  the (Luckhurst  Similarly,  surrounded  other  stressed, particularly  Stelfox  are  a l o t of  by  abundant eat  the  regularly  wild  ungulates  are  in winter.  suffer  massive sheep  V i a b l e lamb p r o d u c t i o n o f m o u n t a i n  correlated  (Ovis  the w i n t e r  when o v e r g r a z i n g l e a d s t o m a l n o u r i s h e d  (Smith  sheep  starve  shrub.  (0. canadensis)  1976).  animals  ( A l c e s a l c e s ) never  know t h a t s h e e p and  nutritionally sheep  consume o n l y  moose  l a r g e the  is usually  are u s u a l l y  amounts o f browse and  limited  Mountain  to suggest  H o e f s and  food  enough t o e a t and  E v e n on h e a v i l y u s e d  sheep u s u a l l y  Stelfox  find  reproduction.  mountain  1973,  population being  i f t h e p o p u l a t i o n grows t o o  e a t most of or  animal  nutrition be  (Hoefs  i m p r o v e d by  and  Similar  ungulates  i n almost  sheep i s Brink  supplemental  nutritional  (Sinclair  a l l cases  die-offs  (Stelfox  h a r v e s t i n g ewes t o r e d u c e 1978).  Bighorn  1977,  of n u t r i t i o n a l  1978; feeding  competition problems McCullough stress  2  there  is s t i l l  The  problem  enough f o o d quality.  (Pearson  but  animal  a stomach f u l l  1969).  and  will  interactions foraging ecology  The  of  simply  be  have a m a j o r  of  food  in obtaining a impact  on i t s  efficiently.  The  range c h a r a c t e r i s t i c s  species.  ThejDptimum  i s the  focus  alter  effort  subalpine  to  spruce  i s o f t e n u s e d by  their their  of t h i s  i s widely  converts  used  the n u t r i t i o n  poplar  Stone's sheep  the  population  foraging  British  habitat.  forest  into  (0. da11i an  Fire  grassland  stonei).  opportunity  to  foraging behaviour  i n range c h a r a c t e r i s t i c s .  to determine the and  behaviour  nutritional  i n northern  Stone's sheep modify t h e i r  I tried  foraging  foraging  improve w i l d l i f e and  of  the  thesis.  of h a b i t a t p r o v i d e d  r e s p o n s e t o a change  foraging  the c h a r a c t e r i s t i c s  Animals should  This alteration  and  of a s p e c i e s c o n s t i t u t e s the  i n an  addition,  die  w e l l adapted to forage  Columbia  how  can  that  accordingly to optimize That  of s u i t a b l e  low-quality  efficiency  obtain  would e x p e c t  between t h e  that  of  to  one  Range b u r n i n g  on  i s not  Therefore,  d e p e n d i n g on  behaviour  study  will  fitness.  environment.  intake.  animal's  diet  behaviour  vary  which  faces  r a t h e r t o o b t a i n enough f o o d  with  condition  will  the  nutritious  animals  available.  I t i s w e l l known t h a t u n g u l a t e s  starvation  highly  food  effect  in  In  of.range  dynamics of Stone's  burning sheep  3  populations burning  i n order t o e v a l u a t e the b e n e f i t s  f o r t h e management o f S t o n e ' s  of  range  sheep.  STONE'S SHEEP Mountain species,  sheep i n North  the bighorns  the t h i n h o r n s are  further  Dall's sheep  sheep (O.d.  America  (Ovis canadensis)  (Ovis d a l l i )  divided  into  (O.d.  dalli)  stonei).  are divided  The  i n the  i n the n o r t h .  two  The  s u b s p e c i e s , the  and  the dark-bodied  two  subspecies  an  central  Yukon where t h e i r  inhabit  mountainous a r e a s of n o r t h e r n B r i t i s h  southern  studied social  i n the p a s t . behaviour  conducted effect  Yukon.  In a d d i t i o n animals,  Geist  s t u d y and  to studying the  the present  animal.  south  and  thinhorns all-white Stone's  sheep i n the  Stone's  T h i s s u b s p e c i e s has  been  sheep  Columbia  Elliot  and  little  (1971) c o n c e n t r a t e d on  b u r n i n g on h o r n  l e a r n more a b o u t big-game  meet.  of t h e s e a n i m a l s , L u c k h u r s t  a range  of r a n g e  know a s F a n n i n ' s  ranges  two  interbreed to  produce  the  i n t e r m e d i a t e form  into  the  (1973)  (1978) d i s c u s s e d t h e  g r o w t h of S t o n e ' s  f o r a g i n g ecology of  s t u d y p r o v i d e d an  sheep.  these  opportunity to  the g e n e r a l ecology of t h i s  important  4  NUTRITION OF RUMINANTS Stone's sheep a r e r u m i n a n t s .  An u n d e r s t a n d i n g o f t h e  foraging ecology of the species  i s impossible  u n l e s s one  c o n s i d e r s b o t h t h e a d v a n t a g e s and t h e c o n s t r a i n t s being  a ruminant e n t a i l s .  ruminant  i s the a b i l i t y  cellulose  in plant  undigestible microflora  The m a j o r  to digest  material  advantage of being a  h e m i c e l l u l o s e and  that  would  f o r a non-ruminant.  can manufacture u s e f u l  vitamins  f o r t h e a n i m a l ( C h u r c h 1980).  digestive  produce v a r i o u s  The maximum f o r a g e  by t h e p a s s a g e r a t e  1961, C o n r a d e t a l . 1964).  gut  i s relatively  fibrous  forage  Because  passage r a t e  that  recycled  of the ruminant  f o o d c a n be i n ruminants i s  Passage  but d e c l i n e s  i s consumed ( P h i l l i p s o n i s relatively  i n t a k e can i n c r e a s e  from  through t h e gut ( B l a x t e r e t  al.  constant  intake  t h e rumen  essential  t o the e f f i c i e n c y  system i s the r a t e a t which  processed. limited  factor  largely  proteins  wastes and a l s o  limiting  be  In a d d i t i o n ,  nitrogen  The  that  rate  through the  somewhat when more and A s h  constant,  1965).  the only  way  i s f o r more o f t h e f o o d t o be  digested. The g r o s s e n e r g y c o n t e n t constant How  o f most f o r a g e s  a n d a v e r a g e s 4.4 k c a l / g m  much o f t h i s c a l o r i c  d e p e n d s on how d i g e s t i b l e  i s relatively  (Maynard e t a l . 1979).  e n e r g y i s u s a b l e by t h e a n i m a l the forage  i s because t h e r e  is a  5  near  1:1  r e l a t i o n s h i p between d r y m a t t e r d i g e s t i b i l i t y  energy d i g e s t i b i l i t y  (Moir  1961).  Because forage d i g e s t i b i l i t y maximum f o r a g e that  food,  effect the  on  i n t a k e and  changes  digestibility  p r e d i c t i o n s about One  analyses. quality  energy  forage  the  us  the  study  of  the  year  food  frustrating  task  to decide  i s much more s a t i s f a c t o r y of the  attempted  this  food a c t u a l l y by  feed  animal  i f one  acid  (DAPA) c o n t e n t ,  are c o r r e l a t e d  with  the q u a l i t y  (Hebert  1973;  Nelson  i n f o r m a t i o n d e s c r i b e s the quality.  Comparison of  DAPA l e v e l s test  of the  protein  represent  items  eats. of  f o r Stone's  can  measure  two  sheep.  the I  for protein  and  v a r i a b l e s which  f o o d consumed by  p a t t e r n of  forage q u a l i t y ,  It  the  the a n i m a l .  e t a l . 1982).  seasonal  between b u r n e d and hypotheses:  of  and  actually  samples  diaminopimelic  ruminant  not  s e l e c t e d by  analysing fecal  forage  selectively,  what  food  on  important  to c o l l e c t  h e r b a g e may  t h a t the  data  ruminants.  for d i g e s t i b i l i t y  p l a n t biomass are a c t u a l l y  quality  t o make  was  of  multiplicative  Therefore,  n u t r i e n t i n t a k e of this  the  energy content  have a  intake.  allow  a n a l y s i s of a v a i l a b l e  i s a very  It  the d i g e s t i b l e  Because g r a z i n g animals  the q u a l i t y  total  of  o b j e c t i v e of  samples throughout  i n f l u e n c e s both  in d i g e s t i b i l i t y  the a n i m a l ' s  and  fecal  a  This food p r o t e i n , and  unburned ranges p r o v i d e d  a  6  i ) Forage q u a l i t y superior ii)  on b u r n e d  Sheep f e e d i n g  quality  (digestibility  of food  and p r o t e i n ) i s  ranges. on b u r n e d  intake  r a n g e s have a  than  sheep u s i n g  higher  unburned  ranges.  Analysis  of m i n e r a l  was a l s o c o n d u c t e d  concentrations  i n forage  i n an e f f o r t t o d e t e r m i n e  e n c o u n t e r e d any s e r i o u s m i n e r a l lick  behaviour  with  the problem of mineral  and s o i l s  i f the sheep  deficiencies.  Mineral  was s t u d i e d t o s e e how t h e a n i m a l s  dealt  nutrition.  FOOD S E L E C T I V I T Y Ungulates s e l e c t i v e l y feed most n u t r i t i o u s several  f o r them.  different  This  levels:  selection  of p a r t i c u l a r  selection  of p l a n t p a r t s  on t h o s e  items which a r e  s e l e c t i v i t y occurs at  i) selection  p l a n t s on t h a t  of range, i i ) range, i i i )  (Jarman a n d S i n c l a i r  R u m i n a n t s a r e more e f f i c i e n t a t s e l e c t i n g diet  when f r e e - r a n g i n g  rations  quality  that  1974).  This  c o r r e l a t e d with  quality  o r new g r o w t h v e r s u s  nutritious with  processed  observation  t h e a n i m a l s do n o t d e t e c t  d i r e c t l y but r a t h e r d e t e c t  positively content  t h a n when p r e s e n t e d  ( B a i l e and Forbes  indicates  a  1979).  the n u t r i e n t  cues which a r e s u c h a s low f i b r e  dead m a t e r i a l .  Arnold  (1966)  7  demonstrated senses used  that  in selective  I examined observing  selective  seasonal  food h a b i t s with in conjunction the  s m e l l and  t a s t e are  t h e most  f e e d i n g by  sheep.  feeding  Stone's sheep  p a t t e r n s of  of  r a n g e use  species a v a i l a b i l i t y .  with  important  forage  quality  and  by  This  data,  by  comparing  information,  was  used to  test  hypothesis: iii)  Stone's sheep s e l e c t  provide  the  Estimates analyses  best  of  r a n g e s and  nutrition  food q u a l i t y  were compared  food  items  which  available.  b a s e d on  to forage  fecal  quality  protein  to test  the  hypothesis: i v ) Q u a l i t y of quality  food  eaten  i s s u p e r i o r t o the  o f a v a i l a b l e h e r b a g e due  to  average  selective  feeding.  INTAKE RATE In a d d i t i o n t o s e l e c t i n g h i g h q u a l i t y grazing rate.  ungulate Presumably  selectivity high q u a l i t y than is  must a l s o m a i n t a i n  an  too  and  intake  items  animal  there  i s an rate.  will  an  food,  adequate  not  An  probably  be  intake  inverse relationship animal  selecting  have a l o w e r  f e e d i n g n o n - s e l e c t i v e l y , and  s e l e c t i v e may  the  able  an  between only  intake animal  t o o b t a i n enough  rate that  food.  8  Therefore,  the  animal  to achieve  the  optimum t r a d e - o f f  factors.  Optimum f o r a g i n g  predict  Sheep feed  energy  The  intake  and  may  individuals.  the  factors may  domestic  of  with  vary sex  two  1971)  would  intake  that  sheep,  intake  rate  length  possible  or  animals that  can  r e l a t e d to foraging  of  foraging be  However, i n  intake  rate.  time of  up  influenced bite size  the  by (Allden  studies  are  rate  of rely  on  some  free-ranging  w h i c h we  I recorded  wide  intake  p r o b a b l y have t o  behaviour of  as  grazing  over a  However, t h e r e  m e a s u r e d and  information  r a t e would go  Detailed  behaviour w i l l  of  sheep.  t o measure d i r e c t l y  wild ungulates.  the  rate  is greatly  semi-tame a n i m a l s .  components o f  requires  which determines the  It  foraging  body s i z e  remains constant  d e n s i t i e s but  free-ranging  net  w i t h d i f f e r e n t range  intake  increases.  i s not  t o maximize t h e i r  and  forage  1970).  captive  as  of  Whittaker  daily  (Schoener  t h i s hypothesis  seem l o g i c a l  tiller  ungulate  be  vary  will  i n f l u e n c i n g the  range of p l a n t  and  theory  these  behaviour  rate.  Testing  quantity  grass  i t s foraging  between  i n s u c h a way  optimum s t r a t e g y  conditions  It  modify  that:  v)  on  should  would e x p e c t  biting  rate  s h e e p under d i f f e r e n t r a n g e  to  and types  9  and  conditions to test  some h y p o t h e s e s r e l a t i n g  effect  of range c h a r a c t e r i s t i c s  intake  rate:  vi) Foraging forage vii)  and b i t i n g  time  higher  on  rate are related to tiller  length.  i s l e s s and b i t i n g  on b u r n e d r a n g e t h a n  r a t e of sheep  on u n b u r n e d  range.  i n f o r m a t i o n on f o r a g i n g r a t e s was i n t e g r a t e d w i t h  the  forage q u a l i t y  the  optimal  energy  and range b u r n i n g  q u a n t i t y and/or g r a s s  Foraging is  The  time  to the  data  and e v a l u a t e d  foraging hypothesis  intake  i n the context o f  i . e . , maximization  of net  rate.  POPULATION CONDITION AND POPULATION DYNAMICS If that  food  limitation  the animals  eat a l l the food,  Heavy s e l e c t i v e quality  o f s h e e p p o p u l a t i o n s does n o t mean  g r a z i n g by s h e e p c a n g r a d u a l l y d e g r a d e t h e  of the remaining  d e p e n d e n t manner pronounced d u r i n g vegetation  what d o e s i t mean?  forage  (Arnold  on t h e range  1960a).  the non-growing  i s not being  in a density-  The p r o c e s s  will  s e a s o n when  probably  t h e o n l y time  . degrade t h e a v a i l a b l e were c o l l e c t e d  to test  grazed  r e p l a c e d by new g r o w t h .  mountain sheep a t normal p o p u l a t i o n d e n s i t i e s ,  be most  For winter i s  when g r a z i n g c a n s i g n i f i c a n t l y forage q u a l i t y . the hypothesis:  In t h i s  study  data  10  viii)  Selective  by S t o n e ' s s h e e p i n w i n t e r  removes  high q u a l i t y  quality  of the range t h a t  Ungulates food  grazing  f o r a g e and t h e r e b y d e g r a d e s t h e winter.  faced with a p r o g r e s s i v e l y  s o u r c e would be  poorer d i e t .  Below  forced  to select  a certain  nutrient effect  The  progressively  forage d i g e s t i b i l i t y  a n i m a l w o u l d be u n a b l e t o compensate because of gut c a p a c i t y .  a  deteriorating  by e a t i n g  resultant  condition,  more  decrease i n  i n t a k e would be e x p e c t e d t o have a  on t h e g r o w t h r a t e s ,  the  and  negative population  dynamics of the a n i m a l s . For  S t o n e ' s sheep I a t t e m p t e d t o t e s t  ix)  Horn  parasite x) H o r n greater burned  and body  growth,  lamb p r o d u c t i o n ,  l e v e l s are related g r o w t h , body and p a r a s i t e  r a n g e compared  the h y p o t h e s e s :  to winter  g r o w t h , and  and  nutrition.  lamb p r o d u c t i o n  l e v e l s a r e lower i n sheep t o sheep u s i n g  unburned  are  using range.  STUDY AREA The  study  was  conducted  British  Columbia  (59°N,  Highway  (Figure 1).  Muskwa Range and M o u n t a i n s and  into  Geology of the a r e a (1973). faulted  The  area  and  Precambrium  i n the  The  Precambrium  study was  area  the  area  was  rocks  the  northern  bands o f  (shales,  Alaska  ranging  i n the  the  Rocky foothills.  folded  Stott  and  conglomerates, i n age  southwest t o T r i a s s i c  of a now  the  i n c l u d e d p a r t s of  from  i n the  southwestern  c o n t a i n numerous i g n e o u s  site  River,  d i s c u s s e d by T a y l o r and  limestones)  formations  of  t h e Rocky M o u n t a i n  i s composed of  sedimentary  sandstones,  study  S t o n e Range of  extended  of T o a d  125°W) n e a r M i l e 422  The  the  i n the v i c i n i t y  d i k e s , one  abandoned c o p p e r  northeast. p a r t of of  the  which  mine.  Topography ranges from s t e e p , p r e c i p i t o u s , g l a c i e r topped the  peaks  i n the  northeast.  southwest  t o more r o l l i n g  E l e v a t i o n s range  f r o m 750  M o u n t a i n s have been e x t e n s i v e l y g l a c i a t e d c i r q u e s and  U-shaped v a l l e y s .  f a n s c r e a t e numerous open a r e a s Soils  i n the a r e a  al.  (1978).  and  eutric  along  G e n e r a l l y the v a l l e y  and  m.  exhibit  s l o p e s and  alluvial  forested slopes.  bottoms c o n t a i n  b r u n i s o l s , f o r e s t e d mountain  soils.  m t o 2,500  in  were d e s c r i b e d by V a l e n t i n e e t  composed o f h u m o - f e r r i c regosol  Tallus  country  podzols  and  slopes  dystric  are  t h e a l p i n e p e a k s have  12  Figure 1.  Location and map of the study area.  Elevations in meters.  13  There  i s a permanent w e a t h e r s t a t i o n  F e d e r a l Government w i t h i n t h e s t u d y Long t e r m , a v e r a g e The  weather d a t a  b i o g e o c l i m a t i c zones  maintained  a r e a a t Muncho L a k e .  a r e summarized  (Krajina  i n Table  1.  1976) o f t h e a r e a  include  t h e B o r e a l W h i t e and B l a c k  extends  up t o a b o u t  between  1400 a n d 1600 m, a n d t h e A l p i n e T u n d r a  1600  by t h e  Spruce  Zone w h i c h  1400 m, t h e S p r u c e - W i l l o w - B i r c h  Zone  Zone above  m. White  spruce  (P. m a r i a n a ) f o r m elevations, lodgepole  the climax  but f i r e  pine  tremuloides  (Picea qlauca)  forest  has induced  type  spruce a t low  the establishment of  (Pinus c o n t o r t a ) , poplars  (Populus  a n d P. b a l s a m i f e r a ) a n d / o r g r a s s l a n d i n many  a r e a s d e p e n d i n g on t h e f i r e Bearberry  and b l a c k  frequency  (Parminter  ( A r c t o s t a p h y l o s u v a - u r s i ) and mountain  (Vaccinium  v i t i s - i d a e a ) a r e common g r o u n d c o v e r  elevation,  and L a b r a d o r  buffalo-berry  t e a (Ledum  s p p . ) , and r o s e  spruce (Betula  (Rosa  (Salix  Spruce-Willow-Birch forest  a r e common  cranberry (Alnus  shrubs.  Zone i s a t r a n s i t i o n  zone  t o a s h r u b b y z o n e d o m i n a t e d by s c r u b  glandulosa)  and w i l l o w s .  d o m i n a t e d by m o u n t a i n avens (Carex  groenlandicum),  spp.), a l d e r s  acicularis)  cranberry a t low  (Sheperdia c a n a d e n s i s ) , high-bush  (Viburnum e d u l e ) , w i l l o w s  The  1981).  birch  The A l p i n e Zone i s  (Dryas  spp.), net-veined willow  from  integrifolia),  (Salix  sedges  r e t i c u l a t a ) , and  Table 1. Average climatic data for Muncho Lake, British Columbia (1955-1978).  Month  J  F  M  A  M  J  J  A  S  0  N  D  Total  Daily Maximum Temperature *  -13.0  -7.3  -2.0  6.7  13.4  18.2  20.2  18.7  13.6  6.9  -2.5  -10.1  -  Daily Minimum Temperature  -24.4  -19.8  -16.3  6.1  0.6  5.7  7.7  6.1  2.1  -2.9  -12.2  -20.6  -  Average Daily Temperature  -18.7  -13.6  -9.2  0.3  7.1  12.0  14.0  12.5  7.9  2.1  -7.4  -15.4  -  0.9  0.0  0.4  0.8  35.7  59.7  78.0  58.3  38.5  15.5  5.7  0.4  293.9  Snowfall  27.4  27.0  17.0  6.1  4.7  0.4  1.0  0.0  0.9  9.8  21.2  28.6  144.1  Total Precipitation  35.2  33.3  19.9  6.8  43.0  60.2  79.4  58.3  39.0  23.8  27.3  32.8  459.0  Days with Precipitation  12  11  13  13  Rainfall**  9  * temperatures i n C. **rain and snow i n mm of water  9  4  7  13  10  9  10  120  15  numerous l i c h e n s and detail  T h i s zone  i n the  results section.  A partial  plant collection  Gilmore  (1981) and  Columbia A.  forbs.  f o r the area  was  made  i s l o c a t e d i n t h e U n i v e r s i t y of  herbarium.  Chiska  is discussed in  i n 1982  A more c o m p l e t e c o l l e c t i o n  i s l o c a t e d i n the  B.C.  by  British  by  Provincial  Museum  Herbarium. Sheep p o p u l a t i o n s River,  and  Sulphur  extensive areas intentionally in  1978.  the  over  9 years were  Creek area  of b u r n e d  b u r n e d by  A n a l y s i s of  Toad and  fires  Racing  (Parminter,  80  burn  started  (Parminter, Other  s c a r s on  a t an  the  fire pers.  f o r at  canadensis),  interval Most of  Branch  course  that regular  of about these  was  every  fires  and  several  of t h i s p r o j e c t . area  are  for a small  the past  primarily  (5 km ) 2  area  120  recent  shows  no  years  comm.).  large ungulates  (Alces a l c e s ) ,  Wildlife  trees indicated  Otherwise the  least  to  Creek v a l l e y  to create rangeland  unburned range except  of  F i s h and  Delano v a l l e y  i n the Delano v a l l e y .  evidence  Sulphur  p e r s . comm.).  were s t a r t e d d u r i n g  on  B.C.  years  Sheep i n t h e Yedhe and found  Racing  ( F i g u r e 1) have a c c e s s  range.  the  fire  the Toad R i v e r ,  R i v e r v a l l e y s have e x p e r i e n c e d  the past  intentionally  fires  i n p a r t s of  caribou  mule d e e r  i n the  study  area  (Ranqifer tarandus), (Odocoileus  i n c l u d e moose elk  h e m i o n u s ) , and  (Cervus mountain  16  goats  (Oreamos americanus).  l o c a t e d i n the  Appendices.  A b i r d and mammal l i s t i s  17  METHODS  RANGE USE PATTERNS AND GROUP COMPOSITION COUNTS Sheep were throughout with the  regularly  the area.  several  and c l i m b i n g  T h e s e o b s e r v a t i o n s were  helicopter  and f i x e d - w i n g  1980  August,  supplemented  surveys  throughout  f i x e d wing  1980  helicopter  March,  1981  f i x e d wing  April,  1981  fixed  July,  1981  October,  April,  helicopter  1982  helicopter  1982  November,  fixed  1982  learning  local  specific  where t o l o c a t e  conditions.  major m i n e r a l could  o u t f i t t e r s , and  lick  helpful  t h e sheep.  o f s h e e p were r e c o r d e d a l o n g  a classification  lamb:yearling:ewe  size  residents,  o f B.C. F i s h a n d W i l d l i f e B r a n c h were  Counts and l o c a t i o n s complete  wing  f i x e d wing  Conversations with John E l l i o t t  wing  helicopter  1981  February,  as  by h i k i n g  season: May,  in  located  a s was p o s s i b l e  F o r t h e unburned a r e a ,  under I used  only  r a t i o s w h i c h were c o l l e c t e d i n J u l y ( C h u r c h i l l mine) where a l a r g e  be o b s e r v e d  repeatedly  (Figure  with  at a  sample  1). For the  18  burned  range, the o n l y c o m p o s i t i o n counts i n which  c o n f i d e n c e were w i n t e r c o u n t s w h i c h c o u l d repeatedly  from a group which  (Fertilizer  Mountain)  w i n t e r c o u n t was confident winter.  that  remained  a l s o t h e o n l y one  taken  on t h e same  t h r o u g h o u t w i n t e r and  slope  spring.  f o r which  summer r a n g e  The  I could  t h e c o u n t e d s h e e p had u s e d b u r n e d  F o r c o u n t s on a l p i n e  impossible  be  I had  be  range i n  i t was  t o know where t h e s h e e p had w i n t e r e d .  RANGE ANALYSIS Forage biomass  o f r a n g e s was  plant  from 6-10  the  material  Most p l o t s were 0.25 used  m  2  m e a s u r e d by c l i p p i n g a l l  randomly  selected  but o c c a s i o n a l l y  1 m  i n a l p i n e a r e a s w i t h v e r y low b i o m a s s .  were s o r t e d  into  live  forbs,  live  plots. plots  2  The  were  samples  g r a m i n o i d s , and  standing  d e a d m a t e r i a l and t h e n a i r d r i e d  f o r s e v e r a l days u n t i l  constant  These  weighed  weight  was  to the nearest  then oven-dried at information was  maintained. 0.1  100°C and  a correction  calculated  g.  samples  Some samples then weighed.  factor  t o c o n v e r t a i r d r y weight  were  (n = 53) From  e q u a l t o 92.5%  a  were  this  ± 0.41  i n t o oven  (SE)  dry  weight. Tiller randomly measuring  l e n g t h of g r a s s e s and  selecting  s e d g e s was  10 o r more i n d i v i d u a l  t o t h e n e a r e s t mm  the length  measured  tillers  by  and  from the ground  to  19  the  t i p of  the  r a n g e s was A pointer  longest  leaf.  measured by was  a modified  dropped at  The  p r o c e d u r e was  continued  The  p r o c e d u r e was  repeated u n t i l  f o r a l l the  transects  had  Samples of collected Only  no  great  included.  the  the  d e t e r m i n e d by  the  the  stabilized the  Wildlife  of  Soil  Science,  a  transect  recorded.  the  pooled  additional  average  values.  browse were  plant  but  parts  for storage.  Habitat  I_n v i t r o  forage  method.  for quality analysis.  from d o m e s t i c  a n a l y s i s of  of  points/transect.  and  f o r b s , and  two-stage T i l l e y  rumen f l u i d  Mineral  was  average of  p r o x i m a t e a n a l y s i s , and  U n i v e r s i t y , Pullman.  Columbia.  50-100  f o r b samples, a l l the  c o n d u c t e d by  Department  for  season  transect  pointer  Samples were a i r d r i e d  digestibility,  utilizing  the  e f f e c t on  graminoids,  point  were c o l l e c t e d f r o m browse p l a n t s  g r a m i n o i d and  State  transects  throughout  leaves  h i t by  composition  i n t e r v a l s along  the  was  species  random  and  data  plant  Species  protein Lab.,  were I_n  vitro  analysis  Washington  digestibility  and  for  Terry  was  (1963) method  sheep.  s a m p l e s was  U n i v e r s i t y of  done by British  the  20  collected. Soil  Analysis  Sciences,  Exchangeable in  was c a r r i e d o u t by t h e D e p a r t m e n t o f  U n i v e r s i t y of B r i t i s h  C a , Mg, a n d K were d e t e r m i n e d by  1N NH2OAc.  Walkley-Black  t e c h n i q u e and phosphorous  the Bray t e c h n i q u e .  FECAL  ANALYSIS samples  Nitrogen, Habitat cell  Lab., Pullman.  ruminants.  DAPA  o f rumen b a c t e r i a The amount  to the rate  correlated al.  were a i r d r i e d a f t e r  was d e t e r m i n e d  collection.  a s h , a n d DAPA a n a l y s i s was done a t t h e W i l d l i f e  walls  related  desorption  T o t a l c a r b o n was d e t e r m i n e d u s i n g t h e  using  Fecal  Columbia.  i s a p e p t i d e found that  o f DAPA  i n the  i s n o t a b s o r b e d by  i n the feces  o f rumen m i c r o b i a l  with d i g e s t i b l e energy  i s thus  a c t i o n and  intake  (Nelson et  1982).  FOOD HABITS Food  habit  analysis  included  rumen a n a l y s i s , and d i r e c t were c o l l e c t e d f r o m Rumen  samples  Analysis  done a t t h e W i l d l i f e for  died  i n formalin  from  involves  samples  accidents.  and f e c a l  Lab., Pullman.  samples  analysis,  The rumen  o f rumen a n d f e c a l  Habitat  b o t h rumen a n d f e c a l  fragment  observation.  5 animals that  were s t o r e d  were a i r d r i e d .  fecal  samples  samples  was  The t e c h n i q u e  preparing  a  21  Rumen s a m p l e s were s t o r e d  i n formalin  were a i r d r i e d .  o f rumen and f e c a l  Analysis  done a t t h e W i l d l i f e for  both  slide and  Habitat  rumen and f e c a l  slide  Lab., Pullman.  samples  involves  from a s o l u t i o n of the m a t e r i a l ,  i d e n t i f y i n g plant using  details In  and f e c a l  material  addition,  some  tissue.  on t h e  For  (undated). on f o o d  by o b s e r v i n g  difficult  t o s e e what an a n i m a l was e a t i n g  being  a  a t 300 random p o i n t s  information  b u t i t was e a s y  was  The t e c h n i q u e  preparing  collected  grazing  samples  s t a i n i n g the s l i d e ,  c h a r a c t e r i s t i c s of epidermal  s e e N e l s o n and D a v i t t  samples  sheep f e e d i n g .  habits  was  I t was u s u a l l y when  very  i_t was  t o d e t e r m i n e which p l a n t s  were  browsed.  PARASITOLOGY Fecal ranges dried  i n m i d - w i n t e r and e a r l y f o r storage.  of D r . W. the  samples were c o l l e c t e d from b u r n e d a n d u n b u r n e d 1  Samples were a i r  P a r a s i t e c o u n t s were done by t h e l a b  Samuels, U n i v e r s i t y o f A l b e r t a , Edmonton  Baermann  FORAGING  spring.  technique  f o r recovery  of f i r s t - s t a g e  using larvae.  BEHAVIOUR  Time b u d g e t  information  population  every  behaviour  of each  was c o l l e c t e d by s c a n n i n g t h e  5 o r 10 m i n u t e s a n d r e c o r d i n g t h e individual.  O b s e r v a t i o n s were made a t  22  distances  r a n g i n g from  telescopes. Days w i t h animals  500  m t o 5 km  Observations extended  incomplete data caused  L o s s of v i s i b i l i t y  by  was  w e a t h e r o r a n i m a l movement. i n t e r v a l except  losing  sight  when I was  cold  t o m a i n t a i n a 5-minute  Most  doing daylong  o b s e r v e r s worked a l t e r n a t i n g each  regularly  scan, behaviour  of  the  from  caused  by  s c a n s were done a t a  for several  1982  On  f r o m dawn t o d u s k .  f o r l o n g p e r i o d s o f t i m e were e x c l u d e d  analysis.  minute  u s i n g 20-40X  5-  done i n t h e w i n t e r o f  s c a n s a l o n e and  interval.  i t was  F o r most  too  scans,  two  2-hour s h i f t s . of each  individual  was  classed  as: i)  f o r a g i n g : head  down and  feeding or d i g g i n g f o r  food w i t h i n a p p r o x i m a t e l y 3 seconds  of s p o t t i n g  the  animal. ii) iii)  resting:  of  after  after  up  f o r more t h a n  3  being spotted.  t r a v e l l i n g : head  seconds  These  ruminating.  s t a n d i n g : s t a n d i n g w i t h head  seconds iv)  l y i n g down, o f t e n  up and  moving  f o r more t h a n  3  being spotted.  four behaviours accounted  the o b s e r v a t i o n s .  Other  f o r the v a s t m a j o r i t y  a c t i v i t i e s (e.g., s o c i a l  interactions,  c o m f o r t movements) c o m p r i s e d  insignificant  amount o f t i m e  i n t h e day  an  of a  Stone's  23  sheep.  Behaviour  behaviour  of rams was  o f ewes and  yearlings.  were a g g r e g a t e d b e c a u s e feeding  groups  and  recorded separately  accurately  observation  c o n d i t i o n s and  maintaining  a 5-minute s c a n n i n g  minute  m e a s u r e d by  snow l e v e l  r a t e was  foraging  counting  accompanied recorder  and  observations  timing  jerking  used  motion The  transcribed behaviour included  feeding feeding  time. was  time.  spent  sheep  snow  for  for scale  (Geist  by o b s e r v i n g an minute  taken.  time  of the sheep's  the  1971).  individual  intervals A bite  3-4  and  was  identified  head  which  c o u n t s were r e c o r d e d on a  tape  later.  searching  and  determined  time  chewing  proportion  the time spent b i t i n g  foraging  t i m e was  t h e amount o f  recorded during  The  by  e s t i m a t e d by c o m p a r i n g  determined  each b i t e .  Foraging  spent  recording  t h e number o f b i t e s  imposed  in different  observing individual  f o r r e p e a t e d 1-2  by a d i s t i n c t  actual  D i g g i n g time  sheep  to  interval.  of the f o r a g i n g  Snow d e p t h was  t o nearby  Biting ewe  part  data  c l a s s e s given the  time c o n s t r a i n t s  f o r a g i n g p e r i o d s and  spent d i g g i n g .  possible  between t h e two  t h r o u g h t h e snow.  d e p t h s was  yearling  occurred together in  not always  distinguish  digging  and  these c l a s s e s  i t was  In w i n t e r , a l a r g e  Ewe  from  of time  budget in addition actually  from the b i t i n g  rate  compared  total  t o the  to  tapes  by  24  Initially,  biting  minutes f o r the  change t h r o u g h o u t  was In  subsequent c o u n t s ,  place  that  easy  an  held  by  the  a one  hour  of  Measurements of  hind  1981  animals.  and  Lambs and  were a t t a c h e d  fishing  to adult  be  baited  length, and  In  horn  1981  net.  July  released with  late  trap  by  salt.  and  trap door  hand  to  Captured  blindfolded. chest  girth,  length  balance,  chest  were t a k e n  but  handled e a s i l y .  ewes.  in  a cage  The  y e a r l i n g s were w e i g h e d  much t o be  in  i n June and  1982.  r e s t r a i n e d and foot  lick  Sheep were c a p t u r e d  them from a s p r i n g too  a mineral  t h i s area  t r a p was  shoulder height,  feasible location  summer.  lumber and  The  a  s h e e p as  to approach.  s h e e p were m a n u a l l y  struggled  (see  which  a rope w h i c h c o u l d  door.  suspending  bout  a b a n d o n e d c o p p e r mine s i t e  sheep used  e a r l y J u l y of  was  I considered  u s e d by  100  constructed  all  foraging  MEASUREMENTS  s h e e p was  up  day.  mid-day.  was  height,  a  were made o v e r a p p r o x i m a t e l y  excess of  d r o p the  during  5  significant  for  extensively  J u n e and  showed no  Therefore,  only  were q u i t e  entire  or  CAPTURING AND  to capture  the  day  around  The  these data  once e v e r y  the  observations period  recorded  same s h e e p t h r o u g h o u t  However, a n a l y s i s of  Results).  r a t e was  for  by  adult  ewes  Numbered  collars  25  In  1982 sheep were captured in rope leg snares.  Rope  snares were l a i d out on the ground and sheep were baited into the area with s a l t .  When one stepped into the noose  the rope was pulled up by hand thereby catching the l e g . The sheep were then wrestled to the ground.  Measurements  were taken as i n 1981 except that adult ewes were tranquilized with 1 ml (4 mg/kg) of Rompun (xylazine hydrochloride) to allow weighing. Horn growth data were obtained from B.C. Fish and W i l d l i f e Branch compulsory reporting forms for hunter k i l l e d sheep in the area from 1976-1981.  26  RESULTS  RANGE USE PATTERNS  WINTER RANGE Most  Stone's  sheep i n t h e study a r e a used  mountain peaks and r i d g e s as w i n t e r Surveys  o f t h e Yedhe, D e l a n o ,  February the  1982, M a r c h  sheep  tendency  1981, a n d A p r i l  r a n g i n g from  characteristic t o be blown  t o be q u i t e all  limited.  appeared  t o be t h e i r appeared  than 3  were blown c l e a r  of less  2  o f snow a n d tracks.  on s l o p e s w i t h h i g h snow  trail  through  burn  a valley  i n such leading  areas from one  I n M a r c h o f 1981, 5 s h e e p were using areas that  had m e l t e d  However, i n t h e w i n t e r o f 1982, no s h e e p  t r a c k s were s e e n  high  The  were u s i n g a t o t a l  i n the Delano  o f snow.  ranges  1000 km ,  windswept peak t o a n o t h e r .  or  These  Such h a b i t a t s  The one example o f t r a c k s  a single-file  clear  ranges.  t o be s u i t a b l e c o n t a i n e d s h e e p o r s h e e p  accumulations.  spotted  1982 f o u n d a l m o s t a l l  In a survey area exceeding  No s h e e p were l o c a t e d  was  2).  River areas i n  of these areas appeared  Most a r e a s t h a t  2  (Fig.  1500 t o 2200 m.  f r e e o f snow.  t h e sheep l o c a t e d  km .  and R a c i n g  (n = 140) t o be u s i n g s u c h  were a t e l e v a t i o n s primary  range  windswept  i n t h e Delano  snow a c c u m u l a t i o n  (> 1 m).  burn,  presumably  due t o  Figure 2. Windswept, alpine winter range i n the Yedhe area (February 1982).  28  The  Toad V a l l e y  subalpine  contains  grassland.  large  a r e a s of  In M a r c h of  1981,  fire-induced,  these  s l o p e s were s n o w - f r e e and were u s e d by a b o u t However, these  i n the winter  of  using  and  t h e s h e e p were r e g u l a r l y  unused  were s n o w - c o v e r e d  and  spotted  the l a r g e  unused  sheep.  and  most o f  by t h e (102  t h e windswept peak o f T o a d M o u n t a i n .  the S u l p h u r Creek v a l l e y ,  40  (January-April),  s l o p e s were s n o w - c o v e r e d  Rather,  =  1982  subalpine  sheep.  sightings)  Similarly,  a r e a s of burned  range  t h e s h e e p were l o c a t e d  11) on t h e s n o w - f r e e p e a k s o f a d j a c e n t m o u n t a i n s .  exception  was  one  slope  on F e r t i l i z e r  burned s l o p e which remained p a r t i a l l y  throughout  t h e w i n t e r due  steepness,  south-facing  to i t s p a r t i c u l a r  aspect,  snow-free area of about  5 hectares  sheep throughout the w i n t e r . winter  r a n g e use was  that  ( F i g . 3).  peaks.  elevation  slopes,  including  u n a v a i l a b l e as w i n t e r  small  33 of  low-  deep snow a r e a s .  t h i s meant u s i n g h i g h windswept  were g e n e r a l l y  This  the general p a t t e r n  most p l a c e s Low  orientation  Stone's sheep sought out  snow o r s n o w - f r e e a r e a s and a v o i d e d  a  snow-free  supported about  Thus,  The  combination of  and p a r a l l e l winds  (n  M o u n t a i n w h i c h was  subalpine,  and e x p o s u r e t o t h e p r e v a i l i n g  in  In  mountain  burned  slopes,  range due  to high  snow a c c u m u l a t i o n e x c e p t i n l o w - s n o w f a l l y e a r s o r i n atypical country  locations. i n winter,  When f l y i n g the o v e r a l l  over Stone's  impression  was  sheep of  immense  29  Figure 3.  B u r n e d , s u b a l p i n e w i n t e r range ( F e r t i l i z e r Mountain) i n a year o f high snowfall (February 1982).  30  areas the  o f empty, b a r r e n m o u n t a i n s c o v e r e d  sheep r e s t r i c t e d  desolate, The  lichens  (Alectoria  altaica  with  and  lesser  forbs  easily  camp.  February  the  In  areas  of  the  accelerated.  Oxytropis  the  (115  the  (Elymus  Use  snow m e l t .  range,  s l o p e was time  used  after  was  by  s n o w - f r e e and  sightings).  their  primarily  most  sheep  activity  and  to  small outcrops was  immediately  most of t h e  c o u l d see  was  in early  for a small area One  ranged  melting  of  i n d e e p snow e x c e p t  late  slope  rocky  In t h e w i n t e r  1982  visible  in  When t h e  along  and  approximately  r a n g e resumed  snow.  Poa)  Vic i a spp.).  of the e n t i r e  of  subalpine,  I arrived  w h i c h snow s h e d d i n g  r e m a i n e d blown c l e a r  Festuca  m o u n t a i n w h i c h was  sheep r e s t r i c t e d total  spp.),  (Aqropyron, spp.,  of  innovatus)  sheep d i s t r i b u t i o n  s l o p e was  area  e d g e s on  covered  (primarily  ryegrass  Fertilizer 1982  Cladina  v e g e t a t i o n on  used  composed  f o r 2 d a y s f o l l o w i n g a snowstorm  a l l the  was  snow on  entire  April  after  The  primarily  on  the e n t i r e  cliff  spp.,  some g r a s s e s  F o r most o f t h e  snow-covered  and  of  observed  sheep.  largely  amounts o f o t h e r g r a s s e s  effect  from my  over  and  and  Cetraria  (Artemisia frigida,  The  26  sparse  spp.,  spp.).  s l o p e s was  of  the wind-swept, a l p i n e peaks  very  spp.)  Poa  with  mountain-tops.  r a n g e was  (Carex  burned  to small, s c a t t e r e d patches  v e g e t a t i o n atop  as w i n t e r  sedges  snow-free  i n d e e p snow  bare  slope  that exposed  31  ground  on t h i s a r e a e v e n  snowstorms. day  central free.  and a r e shown on F i g u r e 4.  initially  left  i t appeared  t h e mountain  activity  a packed  t h e snow t o  area behind  through  i n a s l o w l y expanding they  reached  as the  t h e snow.  as i f the sheep a r e e a t i n g  continued u n t i l  snow-  f e e d i n t h i s a r e a and then  sheep s l o w l y advanced  distance  t o the  r a d i a t e o u t w a r d s by d i g g i n g t h r o u g h  This activity  feeding  each  o f t h i s a r e a w h i c h w o u l d be e s s e n t i a l l y  They would  feed.  off  February  major twice  snowstorms, t h e s h e e p w o u l d r e t r e a t  part  gradually  following  L o c a t i o n s o f s h e e p were o b s e r v e d  throughout  Following  immediately  region. areas  From a t h e snow This  i n which t h e  snow was q u i t e d e e p s o t h e y c e a s e d d i g g i n g a n d r e t u r n e d t o feed again this  i n the packed  a r e a was g r a z e d o v e r  area.  Thus, the c e n t r a l  part of  repeatedly throughout the  winter. The  snow d e p t h  (X ± S.E.) a t t h e edge where t h e s h e e p  c e a s e d d i g g i n g f o r f o o d was 32.4 ± 1.9 cm cm).  Snow d e p t h  sheep ranged within cm  in  23 t o > 100 cm.  the area that  ( r a n g e 0-26 cm).  winter.  23-40  b e y o n d t h i s b o u n d a r y w h i c h was u n u s e d by  from  were r e s t r i c t e d  (range  was u s e d  The a v e r a g e  by t h e s h e e p was  Thus i t appeared  to areas with less  that  than  snow  depth  16.5 ± 2.1  Stone's  sheep  25-30 cm o f snow  Figure 4.  Use of winter range (January-March) on Fertilizer Mountain in a year of high snowfall (1982). Density of dots corresponds to intensity of use.  33  SPRING RANGE The for  s h e e p u s e d low e l e v a t i o n  spring  primarily  range.  (Fig. 5).  Delano  valley  and Yedhe a r e a ,  subalpine  rockslides,  chutes  arrival  In the Delano  used n a t u r a l  streamsides,  (1,200 - 1,500 m) a r e a s  tallus  In a d d i t i o n ,  clearings slopes,  Similarly,  at  sheep on T o a d M o u n t a i n  t h e same t i m e .  same s l o p e widely  once  They a l s o hundred The  t h e snow no l o n g e r  occasionally  meters  burned  discussed  i n subsequent  Sheep a l s o level.  selected  range  from  ( F i g . 6)  on F e r t i l i z e r slopes  Mountain  remained  on t h e  a l t h o u g h t h e y r a n g e d more  restricted  their  movement.  moved t o a r e a s o f t h e s l o p e  lower than t h o s e used  i n T a b l e 2.  ranges  April.  several  i n winter.  species composition of the spring  summarized  grained  burned  throughout the s p r i n g  The  which w i n t e r e d i n the  The s h e e p  w i n t e r e d on s u b a l p i n e  burn i n  i n spring.  in late  moved down t o t h e s u b a l p i n e  about  which  and a v a l a n c h e  o f t h e sheep on t h e s e low e l e v a t i o n  the a l p i n e w i n t e r range o c c u r r e d  alpine  including  the subalpine  was a l s o u s e d by s h e e p  sheep  Forage q u a n t i t y  ranges i s  and q u a l i t y a r e  chapters. spring  r a n g e a t a more  The s h e e p on t h e b u r n e d ,  fine-  subalpine  range  a v o i d e d a r e a s w i t h h i g h amounts o f w i n t e r c a r r y o v e r i n spring  and f e d i n a r e a s t h a t  carryover.  were l a r g e l y  f r e e of  Some o f t h e s e a r e a s l a c k e d v e g e t a t i o n  because  34  Figure 5.  Typical unburned spring range in Yedhe valley (May 1982).  35  Figure 6.  Burned, subalpine spring range on Toad Mountain (May 1982).  36  Table 2.  Species composition (% cover) of several Stone's sheep spring ranges (May-June) i n northeastern British Columbia (1980-1982).  Subalpine burned slopes: Delano Creek  F e r t i l i z e r Mountain  Elymus innovatus  401  A  11%  Graminoids (primarily Elvmus^  57%  Populus spp  Arctostaphylos uva-ursi  10%  Artemisia spp.  15%  Rosa a c i c u l a r i s  101  Oxytropis spjL  9%  Aster spp.  7%  18%  Thalictrum spp.  5%  trace  P o t e n t i l l a spp.  41  Epilobium angustofolium bare s o i l Galium. A c h i l l e a .  5%  Galium. V i c i a ,  Shepherdia.Zygadenus  trace  Solidago. Rosa  Subalpine natural clearings: Delano Creek 1  Delano Creek 2  Arctostaphylos u v a - u r s i  75%  Dryas i n t e g r i f o l i a  44%  Juniperus spp.  10%  Arctostaphylos uva-ursi  24%  Elymus i n n o v a t u s  10%  Graminoids  9%  Betula glandulosa  9%  Potentilla fruticosa  5%  Arctostaphylos rubra  5%  Qxytropis, F r a p a r i a, Saxifraga. P o t P n t i l l f i  trace  Arnica. Shepherdia, Silene  trace  37  it  was  removed by heavy g r a z i n g t h e p r e v i o u s w i n t e r  whereas o t h e r a r e a s naturally  l a c k e d v e g e t a t i o n because  unproductive  (e.g., c l i f f  T h e s e a r e a s c o u l d be v i s u a l l y by  t h e dark  covered  in senescent  carryover areas.  compared  A scan  Mountain low  c o l o u r compared grass.  t o 145  ±  edges,  identified  found  27  amounts o f c a r r y o v e r and  brown o f  g/m  s u r v e y o f s h e e p f e e d i n g on  in spring  outcrops).  Such a r e a s had (S.E.)  were  from a d i s t a n c e  t o the golden  17.2  they  areas  almost on  2  no  the  unused  Fertilizer  sheep f e e d i n g i n a r e a s 0 feeding in areas  with  with  abundant c a r r y o v e r .  ALTITUDINAL MIGRATION TO Movement  from  gradual process. moved from in  SUMMER RANGE  spring  range  t o summer range  In t h e D e l a n o  subalpine clearings  and  i n May  s p r u c e - w i l l o w - b i r c h zone v a l l e y s  high alpine  p e a k s by J u l y  i n May  had  this  reached  sheep  clearings to  Similarly,  i n the  elevation  burned  i n June  and  ( F i g . 7).  migration corresponded  progressively during  in July  the  June and  t o t h e s p r u c e - w i l l o w - b i r c h zone  the h i g h a l p i n e The  low  a  to s i m i l a r  in early  ( F i g . 7).  T o a d R i v e r a r e a , s h e e p moved from slopes  Yedhe a r e a  was  to the onset  higher elevations.  p e r i o d corresponded  The  of green-up a t  location  of  sheep  t o a r e a s where new  a h e i g h t of a p p r o x i m a t e l y  10 cm.  By  grass  the  time  2500n  Figure 7. Elevation of range use (mode ± range) by Stone's sheep i n northeastern British Columbia (1980-1982) throughout the year.  39  the  grass  had grown  longer  s l o p e s where p r o d u c t i o n movement c o n t i n u e d found  on h i g h  higher  t h e s h e e p had moved  began l a t e r  until  a l p i n e p e a k s a n d r i d g e s and t h e r e Exceptions  seemed t o be r e l a t e d  than  (Mineral The  foraging.  to t h i s  t o movements  which r e s u l t e d i n the animals other  This  J u l y a t w h i c h t i m e t h e s h e e p were  ranges a v a i l a b l e .  pattern  (Fig. 8).  to higher  being  general  to mineral  i n areas  T h i s phenomenon  were no  licks  f o r reasons  i s discussed  later  Nutrition). species composition  described  i n Table  o f t h e summer r a n g e s i s  3.  F A L L RANGE Range use was e x t r e m e l y sheep being subalpine November in  variable during  l o c a t e d from h i g h  burned  slopes  the f a l l  a l p i n e p e a k s t o low,  i n O c t o b e r and November.  1982, 54 s h e e p were s i g h t e d on h i g h  the Yedhe/Delano a r e a  with  but d u r i n g  In  a l p i n e peaks  t h e same s u r v e y  20  s h e e p were u s i n g  t h e D e l a n o b u r n a n d an a d d i t i o n a l 44  s h e e p were u s i n g  burned  Toad Mountain were u s i n g that  to  14 s h e e p were u s i n g  burned,  sheep w i t h  extensive  slopes along  subalpine  access  use o f them i n f a l l  burns used the a l p i n e .  River.  the top r i d g e while  slopes.  t o burned,  the Racing  On 32  O v e r a l l i t appeared  subalpine  s l o p e s made  whereas s h e e p w i t h o u t  access  40  40  n  May  June  July  August  MONTH Figure 8. Relationship between t i l l e r length of new'grass (X ± 951 C.I.) and range use by Stone's sheep in spring and summer. Star indicates area where most sheep are located at that time of the year.  41  Table 3.  Species composition (% cover) of several Stone's sheep summer ranges (June-July) in northeastern B r i t i s h Columbia (1980-1982). .  Spruce-Willow-Birch Zone: Toad Mountain Dryas i n t e g r i f o l i a  241  Rhododendron lapponicum  171  Betula spp.  121  Graminoids  10%  Vaccinium spp.  7%  Lupinus arcticus  7%  Arctostaphylos uva-ursi  6%  Ledum groenlandicura  41  P o t e n t i l l a , Pvrola  These species form the ground cover between Betula and S a l i x stands which cover 70-90% of the area.  trace  Alpine Zone: F e r t i l i z e r Mountain  Magnum Creek Dryas i n t e g r i f o l i a  40%  Lichens  28%  Salix reticulata  11%  Dryas i n t e g r i f o l i a  17% 15%  Carex spp.  9%  Carex spp_.  Lupinus arcticus  8%  Lupinus arcticus  8%  Festuca a l t a i c a  5%  mosses  8%  S a l i x spp_.  7%  Vaccinium spp_.  3%  Anemone spp. Polygonum spp. Astragalus, P o t e n t i l l a . Cassiope, Silene, Poa, Phyllodoce  •;5% 4% trace  Pedicularis, P o t e n t i l l a , Equisetum, Delphinium  trace  42  Use  of n a t u r a l s u b a l p i n e  observed.  clearings in fall  Most o f t h e s h e e p u s i n g  were i n a r e a s  adjacent  subalpine burns  to important  Spatial  OF  SEXES  Although  rams t e n d e d  on t h e same  range.  Although  of groups  supported  16 ewes, 8 lambs,  t h e g r o u p o f 9 rams  stay together,  as  t h e ewes a n d o f t e n t h e g r o u p s became c o m p l e t e l y Similarly,  contained  both  small areas. ewe a l o n e  regularly  most p a t c h e s  foraged  tended  to  mixed.  they  types  F o r example, t h e w i n t e r / s p r i n g  Mountain  9 rams i n 1982.  i n the  t o be i n g r o u p s  from ewes a n d y e a r l i n g s , b o t h  r a n g e on F e r t i l i z e r and  on t h e  s e p a r a t i o n o f s e x e s was n o t a p p a r e n t  study.  segregated foraged  often  believe  rams a n d ewes l i v i n g  together  area  inter-  range  on t h e same  One e x t r e m e example was a l a r g e ram a n d a  together  on an i s o l a t e d  inter-mixed.  that s p a t i a l  phenomenon  i n t h e same  of a l p i n e winter  peak i n w i n t e r .  ewe g r o u p s a l s o u s e d t h e same r a n g e s and  areas  slopes.  SPATIAL SEPARATION  present  in fall  alpine wintering  w h i c h were u s e d when d e e p snow a c c u m u l a t e d subalpine  was n o t  i n these  Overall,  Ram and  i n s p r i n g a n d summer  t h e r e was no r e a s o n  to  s e p a r a t i o n o f s e x e s was a common Stone's  sheep.  43  FORAGE PRODUCTION AND  PATTERN OF The  a  onset  of m a j o r g r e e n - u p o f  burned s l o p e s  i n 1980  limited  amount of new  on  subalpine  subalpine  using  these  e a r l y as  of  new  grass on  p l a n t s was dividing  long before and  this  Artemisia  at the  burned ranges.  same t i m e  much l e s s  than  as  sheep  production  However, t h e these  time.  on  Therefore,  on  was  plants  Green-up  9).  a v a i l a b l e i n May  late  However, t h e r e  i n 1981.  ( F i g u r e s 8 and  p l a n t s on  much l e s s . standing  estimated  l e n g t h and  the  burned s l o p e s  the  w h i c h was  natural  production  from  quantity  natural  t h a t a v a i l a b l e on  burned  (Fig. 9).  those  May  5 i n 1982.  mid-March  s h e e p on  vegetation  The  in  ranged  clearings occurred  burns  c l e a r i n g s was  as  area  on  n a t u r a l c l e a r i n g s c o u l d o b t a i n new  as  slopes  graminoids  scattered Oxytropis  begun g r o w i n g by  natural  i n the  t o a b o u t May  In p a r t i c u l a r , had  STONE'S SHEEP RANGES  PRODUCTION  subalpine, April  BIOMASS ON  tiller  n a t u r a l c l e a r i n g s were as  ( F i g . 8)  Tiller  from the  weight  burned s u b a l p i n e  by  ( F i g . 10).  the  The  w e r e : 30 to  of  c a l c u l a t e d by weight/tiller  r e l a t i o n s h i p between  c l e a r i n g s compared slopes.  the d e n s i t y  d e n s i t y was  c r o p of g r a s s  c a l c u l a t e d i n t h i s way subalpine  but  tall  tiller  densities  tillers/m 180  tiller  2  on  tillers/m  2  on  ISO  140  130  H  MONTH  Figure 9.  Seasonal pattern of graminoid production (X ± standard deviation) on sheep ranges i n northeastern British Columbia (1980-1982) .  45  GRASS  TILLER  LENGTH  (cm)  Figure 10. Relationship between mean t i l l e r length and mean t i l l e r weight of grasses on Stone's sheep subalpine spring ranges.  46  Early range and  forb production  included Oxytropis,  Epilobium.  Astragalus,  By  on  the  Fragaria, Potentilla,  l a t e May,  Solidaqo,  and  s l o p e s used as  Thaiictrum,  spring Achillea,  Vic ia,  E r i q e r o n p l a n t s were a l s o  growing. The  f o r b s p e c i e s were s i m i l a r  clearings with  grass,  slopes in  and  burned  the  (Figure  subalpine  b i o m a s s of 11).  Dryas  t h e measurement of  i t was  sheep.  f o r b s was  sort. up  The  much h i g h e r was  not  i n the  difficult  but  as  on  burned  included  i t often  particularly  a l s o extremely  for areas  2  2)  f o r b s because a l t h o u g h  amount o f D r y a s on  t o 30-40 g/m  natural  (Table  integrifolia  o n l y a m i n o r component  D r y a s was  both  slopes  formed a complete ground c o v e r , areas,  on  i n the diet  alpine  of  the  to c o l l e c t  and  p l o t s t h a t were c l i p p e d  where i t formed c o m p l e t e  was  ground  cover. Leaf  emergence on  cottonwoods o f May  on  measured  poplars  (P. b a l s a m i f e r a )  subalpine since  slopes.  i t was  tremuloides)  began d u r i n g  the  half  not  u n l i m i t e d f o r any  sheep  browse.  s h e e p moved upwards f r o m t h e  subalpine  t o the  Spruce-Willow-Birch  Zone i n e a r l y J u n e t h e y  moving  t o an  tiller  length  area  and  latter  Browse b i o m a s s was  essentially  w h i c h c h o s e t o f e e d on When t h e  (Populus  of  lower  forage  (Figs.  8 and  9).  q u a n t i t y and  Sheep moving up  burns were  shorter from  the  1101 10090-  fr  a SUBALPINE CLEARING •  SUBAIPIME  BURN  O  SPRUCE-WlllOW-BIRCH  •  ALPINE  80-  E  CD 0)  fD OC O u.  706050-  UJ  40-  ZJ  30-  >  2010-  September  Figure 11. Seasonal pattern of forb production (X ± standard deviation) on Stone's sheep ranges in northeastern British Columbia (1080-1982).  48  natural  s u b a l p i n e c l e a r i n g s were a l s o moving t o an a r e a o f  shorter  grass  b u t f o r a g e q u a n t i t y was s i m i l a r .  emergence on w i l l o w s  ( S a l i x ) and b i r c h e s  (Betula  glandulosa)  i n t h i s area  s h e e p moved  into the high a l p i n e i n July,  again  moving  t o an a r e a  lower  forage  biomass.  Peak subalpine  occurred  i n mid-June.  of short grasses  standing crop occurred and l a t e J u l y  Leaf  in early  i n the a l p i n e .  they  When t h e were once  and s e d g e s a n d  July  i n the  The s u b a l p i n e  b u r n s h a d by f a r t h e g r e a t e s t q u a n t i t y o f f o r a g e this in  time  t h e s h e e p were f e e d i n g on t h e s p a r s e  but a t  vegetation  the a l p i n e . Available  this all  time  green  forage  d e c l i n e d on a l l r a n g e s  as v e g e t a t i o n g r a d u a l l y matured.  v e g e t a t i o n had c e a s e d  dormant v e g e t a t i o n  By  after  October,  g r o w i n g a n d sheep h a d t o f e e d on  f o r the d u r a t i o n of the winter.  WINTER RANGE Dormant v e g e t a t i o n was a b u n d a n t slopes 23).  i n February-March  During  this  2  the winter  o f low snow a c c u m u l a t i o n  (X ± SE, n =  t o t h e sheep.  (1981) t h e  M o u n t a i n were a b l e t o f e e d  forage quantity.  burned  were u s u a l l y snow-  f o o d u s u a l l y was n o t a v a i l a b l e  s h e e p on F e r t l i z e r high  (162.0 ± 17.5 g/m )  However, b e c a u s e t h e s e a r e a s  covered,  on s u b a l p i n e  i n areas of  However, i n 1982, r e s t r i c t i o n o f  49  the  sheep t o a  small  consuming v i r t u a l l y Immediately during  the  standing grazing  area a l l of  adjacent winter  still  on  had  p l u s an  grazing area  on  had  remaining  these  that  difficult  i t was  14.5  slope.  snow-covered  g/m  (n = 5)  2  in spring.  of p l a n t  restricted  1982.  been  i s obvious  removed e s s e n t i a l l y  material  ±  of  This  in Figure  forage  undetermined q u a n t i t y  F e b r u a r y of  heavy  12.  T h e r e was  of  ridges  lichens.  a  Heavy  vegetation  little  to c o l l e c t  and  i n t h e D e l a n o and  a l l the so  (Figures 9  with  few  by  vegetation grams o f  Yedhe late  left  plant  for laboratory analysis.  When t h e s e clearings (n = 5)  97.6  from t h a t  windswept a l p i n e r i d g e s began  a much l o w e r a v a i l a b l i t y 11),  forage  w h i c h had  snow-free areas  Sheep w i n t e r i n g  snow r e s u l t e d i n them  the  areas  dead v e g e t a t i o n of  by  of  s h e e p moved down t o n a t u r a l  i n the  s p r i n g they  standing  w h a t e v e r new  encountered  dead v e g e t a t i o n  g r o w t h was  present.  subalpine  24.8  ± 3.9  in addition  to  g/m  2  50  F i g u r e 12.  Boundary between h e a v i l y g r a z e d a r e a and s n o w - c o v e r e d , u n g r a z e d a r e a on s u b a l p i n e w i n t e r range ( F e r t i l i z e r Mountain 1982).  51  FORAGE QUALITY  WINTER FORAGE Winter low  f o r a g e was  in protein  4).  and  Statistical  the c o n f i d e n c e difference  remaining  digestibility  intervals  (P > 0.1)  There on  was  than  the  covered  i n snow and  and  f o r a g e on  lignin  and  than  f o r a g e from  suggest  quality this  that  of the  remaining  forage remaining  no  forage  areas.  in  had  sheep.  higher  and  i n both  poorer  lower  of  been  Remaining in protein,  in fibre  areas.  to dry  (ADF)  Although  significant,  in a  they  decreased  f o r the a n i m a l s .  Most  m a t e r i a l i n a r e a s o f h e a v y g r a z i n g was  s t e m s compared ungrazed  was  areas that  heavy g r a z i n g r e s u l t e d  Table  of a l p i n e  statistically  and  comparison  the w i n t e r  a r e a s was  ungrazed  15,  There  a r e a s was  c o n t e n t s and  t h e s e d i f f e r e n c e s were n o t do  that  ungrazed  grazed  cell  on  e q u a l l y poor  u n a v a i l a b l e to the  i n the h e a v i l y  digestibility,  grazed  lignin  ( F i g u r e s 13 -  the q u a l i t y  indication  the h e a v i l y  and  i n the graphs.  between  an  (ADF)  were b a s e d  f o r a g e ; i t was  quality  forage  in fibre  comparisons  subalpine winter areas.  high  leafy material available  i n the  of hard  50 a  SUBALPINE  CLEARING  •  SUBALPINE  BURN  O  March  April  June  May  SPRUCE-WILLOW-BIRCH  July  August  MONTH  Figure 13. Seasonal pattern of ADF concentrations in graminoids (X ± 90% C.I.) on different Stone's sheep ranges in northeastern British Columbia (1980-1982).  on  25  n  •  SUBALPINE CLEARING  •  SUBALPINE  BURN  O  SPRUCE-WILLOW-BIRCH  •  ALPINE  2<H  Z UJ r—  o  15^  oc  0.  UJ O OC UJ  i<H  a UNGRAZED 5^  HEAVILY GRAZED  March  April  May  June  July  August  MONTH Figure 14. Seasonal pattern of crude protein concentrations i n graminoids (X ± 90% C.I.) on different Stone's sheep ranges i n northeastern B r i t i s h Columbia (1980-1982).  5 O SUBALPINE  CLEARING  •  BURN  O •  T  —  1 March  SUBALPINE  SPRUCE-WILLOW-BIRCH ALPINE  1 April  I May  * June  I  * July  , August  MONTH Figure 15. Seasonal pattern of lignin concentrations in graminoids (X ± 90% C.I.) on different Stone's sheep ranges in northeastern British Columbia (1980-1982).  55  Table 4.  In v i t r o dry matter d i g e s t i b i l i t y {%) of graminoids and forbs from Stone's sheep ranges i n northeastern B r i t i s h Columbia (1980-1982).  Location  Graminoids  Forbs  + SE)  n  -heavily grazed  36.5+2.6  4  -ungrazed  39.8+3.7  5  32.1  1  65.1+ 0.4  3  51.9+ 3 . 7  3  43.3+5.2  3  May 15  56.2  1  June 25  48.0  2•  June 7  50.5  1  June 25  57.0+ 0 . 2  4  June 25 Carex  53.8+1.8  June 25 Festuca August 1  55.3 57.0+ 2 . 5  (X  ( X + SE)  n  Winter Range: subalpine burned  alpine Spring Range: subalpine burn -May 25 -June 3 June 25  53.2  1  48.4  1  4  59.7+2.6  3  2 7  66.5+ 2.1  8  subalpine clearings  spruce-willow-birch  Summer Range: alpine  56  SPRING-SUMMER FORAGE The  appearance of  dramatic  increase  Stone's sheep. between  the  subalpine As  lignin  burned,  to  content  s h e e p i n May  (Figures  The  i n both  decrease  the  there  older  19).  (ADF)  was  < 0.1)  at high  during  J u l y and  graminoids.  and  i n the  16)  was  were s i g n i f i c a n t l y  forbs  quality  tiller  by  length  and  the  i n the  at  season  and  summer months.  to subalpine  lower  17)  in  in July  graminoids  f o r b s a t h i g h e l e v a t i o n s compared t o t h e  subalpine.  (Figure  18)  were s i g n i f i c a n t l y subalpine  levels lower  of  forbs  (P < 0.1)  f o r b s d u r i n g J u l y and  from h i g h than  August.  (P  slopes  from June-August  ( F i g u r e s 14 and  (P < 0.1)  of  f o r both  Lignin  higher  and  significantly  f o r f o r b s and  Protein levels  overall  vegetation, vegetation  e l e v a t i o n s compared August  an  a l s o shown  Compared t o  more n u t r i t i o u s  ( F i g u r e s 13  13-15).  g r a m i n o i d s and  s e a s o n was  subalpine  quality  fibre  in nutritional  growing  (Figure  was  and  e l e v a t i o n s s t a r t e d t o grow l a t e r  therefore,  and  natural,  to decrease  a  a v a i l a b l e to  r a n g e s and  r e l a t i o n s h i p between g r a s s  phenologically  Fibre  subalpine  increase  13-18).  negative  higher  forage  growing season p r o g r e s s e d ,  throughout  protein  of  in spring provided  no d i f f e r e n c e i n f o r a g e  for protein levels  (Figures  the  i n the q u a l i t y  T h e r e was  levels  grasses  production  c l e a r i n g s u s e d by  the  tendency  new  elevations  levels  for  Lignin levels  in  57  May  July  June  August  MONTH  Figure 16. Seasonal pattern of ADF concentrations i n forbs (X ± 901 C.I.) on different Stone's sheep ranges i n northeastern B r i t i s h Columbia (1980-1982).  58  35  30-1  •  SUBALPINE  O  SPRUCE-WILLOW-BIRCH  BURN  •  ALPINE  25H  20  15  10  May  July  June  August  MONT H Figure 17. Seasonal patterns o f crude p r o t e i n concentrations i n forbs (X ± 90% C.I.) on d i f f e r e n t Stone's sheep ranges i n northeastern B r i t i s h Columbia (1980-1982).  59  •  SUBALPINE  BURN  O  SPRUCE-WILLOW-BIRCH  •  ALPINE  r-  Z  LU  o  OC LU  a  H  May  June  July  August  MONTH  Figure 18. Seasonal pattern of l i g n i n concentrations i n forbs (X ± 90% C.I.) on different Stone's sheep ranges i n northeastern B r i t i s h Columbia (1980-1982).  t  60  GRASS TILLER  Figure 19.  LENGTH Ccm)  Relationship between t i l l e r length and crude p r o t e i n concentrations o f new grasses on Stone's sheep ranges i n northeastern B r i t i s h Columbia (1980-1982).  61  g r a m i n o i d s were e x t r e m e l y interpret forage  ( F i g . 15).  tended  Although  the q u a l i t y  t o be s u p e r i o r t o f o r a g e  intermediate  spruce-willow-birch  were n o t s t a t i s t i c a l l y the  v a r i a b l e and d i f f i c u l t  zone,  significant.  higher  i n May and J u n e . lower  of a l p i n e  from t h e these d i f f e r e n c e s  On t h e r a n g e s  s h e e p were u s i n g , p r o t e i n l e v e l s  significantly  to  that  o f f o r b s were levels  i n graminoids  ADF l e v e l s o f f o r b s were  significantly  (P < 0.1) t h a n  (P < 0.1) t h a n  levels  i n graminoids  from J u n e t o  August. The  l i m i t e d data  protein higher  level than  subalpine  the level  i n the poplar  t e n d e d t o be  browse a v a i l a b l e a t  e l e v a t i o n s (Table 5 ) .  sparse  d r y matter d i g e s t i b i l i t y  t o make v a l i d  Therefore, for  a l s o show t h a t t h e  of high e l e v a t i o n willows  D a t a on j j i v i t r o too  on browse q u a l i t y  values  f o r DMD  comparisons  (DMD)  (Table 4 ) .  were c a l c u l a t e d b a s e d on  p r o t e i n a n d ADF l e v e l s u s i n g t h e e q u a t i o n :  67.05 + 0.23 calculated = 42.  (% p r o t e i n ) - 0.66  from the data  (%ADF), w h i c h  a n d had r  2  values  % DMD = was  = 0.86, S.E. = 3.5, n  These c a l c u l a t e d v a l u e s a r e p r e s e n t e d  Although  were  i n F i g u r e 20.  t h e d i f f e r e n c e s were n o t s t a t i s t i c a l l y  significant,  the data  gradually declining season w i t h h i g h  suggest  t h e same p a t t e r n o f  forage q u a l i t y  e l e v a t i o n forage  throughout being  the growing  superior to  Table 5. Quality analysis of browse species on Stone's sheep ranges i n spring and summer i n northeastern British Columbia (1980-1982).  Source  C e l l Contents %  ADF %  Lignin %  Protein %  In v i t r o DMD ** %  n  June 5 SWB S a l i x *  72.0  19.7  2.9  24.6  -  1  SWB Betula  80.6  13.0  1.7  25.4  -  1  80.7  7.1  3.1  16.5  -  1  15.8-16.7  5.0-5.3  23.9  46.4-60.6  17.2  5.9-6.1  21.7-22.1  46.2-47.7  15.4-15.6  6.2  17.0-18.0  SWB Arctostaphylos  June 25 alpine S a l i x SWB S a l i x subalpine Pormlus  78.1-79.0 78.1 76.9-77.1  46.8  2  J u l y 17  *  alpine S a l i x  77.0  15.3  1.1  30.7  1  SWB S a l i x  73.7  8.2  2.2  16.2  1  SWB= spruce-willow-birch zone  ** DMD = dry matter d i g e s t i b i l i t y  601  55-  •  SUBALPINE  CLEARING  •  SUBALPINE  BURN  O  SPRUCE-WILLOW-BIRCH  •  ALPINE  Q Ul r<  50"  3  O _J  <  o  f-  45  z ui o QC Ul  a  40-  35March  April  May  June  July  August  MONTH Figure 20. Calculated values for dry matter digestibility (DMD) of graminoids on different Stone's sheep ranges i n northeastern British Columbia (1980-1982).  64  subalpine forage i n summer. The d i f f e r e n c e s i n forage q u a l i t y between ranges appeared to d e c l i n e as f a l l approached and by winter was no d i f f e r e n c e between a l p i n e and subalpine  there  forage.  65  FOOD HABITS There are accuracy  of  habits.  The  s e v e r a l problems which d e t r a c t from  the  fragment a n a l y s i s d a t a  major p r o b l e m  digestibility proportion  fecal  of d i f f e r e n t  of d i f f e r e n t  differing  i s that  p l a n t s p e c i e s can  v a l u e s may entirely  not  new  differential plant  accurate  situation.  more a c c u r a t e  because  by  both  t h e r e was example, total in  no  rumen and  i n three cases  other  sedges.  the  cases  Comparison of  time  showed t h a t t h e  f r o m two  from the i n the  but  fecal  these  an  food h a b i t s i s  opportunity  for  the p r o p o r t i o n of  f o o d h a b i t s of  the  same  a n a l y s i s ( T a b l e s 6 and  r e s u l t s d i d not  fecal  analysis  agree e x a c t l y ,  two  fecal  total  grass  tended  rumen a n a l y s e s  to f a l l  suggesting  a n a l y s i s technique  was  and  from A p r i l  rumen s a m p l e s c o l l e c t e d data  For  underestimated  f e c a l a n a l y s i s data  fecal  8)  t o rumen a n a l y s i s whereas  i t overestimated  to data  error  of  s e d g e s compared  1981  values  to c o r r e c t  c o n s i s t e n t p a t t e r n t o the d e v i a t i o n .  g r a s s and  two  to a l t e r  Comparison  showed t h a t a l t h o u g h  factors  of p l a n t types  is less  the  feces  when e x t r a p o l a t e d t o  there  in  Some  Rumen a n a l y s i s o f  digestibility  fragments.  animals  correction  digestibilities  be  result  p l a n t s p e c i e s i n the  r e s e a r c h e r s have d e v e l o p e d  food  differential  from the p r o p o r t i o n i n the d i e t .  for d i f f e r e n t i a l  on  the  a t the  21, same  between that  l e s s than  the the  the  66  Table 6 .  Food habits o f Stone's sheep on unburned range i n northeastern B r i t i s h Columbia (1980-1982) determined by rumen analysis.  March 23 1981 alpine  A p r i l 21 1981 subalpine  A p r i l 21 1981 subalpine  June 20 1981 alpine  June 25 1981 alpine  1  %  %  %  %  38.6 3.8 12.2 0.6 0.0 55.2  8.8 25.7 8.8 0.9 0.4 44.6  2 .3 42 .0 8 .3 0 .0 1 .6 54,.2  6.5 8.0 19.7 0.0 0.0 34.2  10.8 1.1 19.5 0.0 0.0 31.4  Oxytropis Lupinus Dryas Astragalas Other forbs TOTAL FORBS  0.0 0.0 0.0 0.0 0.0 3.8  0.0 1.4 0.0 2.3 5.0 8.7  0,.0 7,.8 1..0 0.,0 8..7 17.,5  0.0 18.0 0.0 0.0 18.9 36.8  48.0 2.7 0.0 0.0 12.5 63.2  Conifers Salix Vaccinium Rosa Populus Betula Other browse TOTAL BROWSE  0.6 0.0 0.0 0.0 0.0 0.0 0.0 2.4  2.6 3.8 5.8 2.2 3.8 4.2 0.0 22.4  0.2 1.9 1.6 0.0 3.8 5.2 0.0 12. 7  0.0 16.4 0.0 1.2 0.0 0.0 9.4 27.0  0.0 1.6 0.0 0.0 0.0 0.0 3.7 5.3  38.6 0.0  9.0 15.3  12. 8 2.8  1.8 0.0  0.1 0.0  Carex Elymus Poa Festuca Other grass TOTAL GRAMINOIDS  Lichen Moss  Table 7.  Food habits of Stone's sheep on subalpine burned range i n northeastern B r i t i s h Columbia (1980-1982) determined by f e c a l analysis.  February 24 March 19 A p r i l 6 A p r i l 22 1982 1981 1982 1982  May 7 1982  May 13 i 9  8  1  May 18 i  June 22 1980  November 1982  9  8  0  Carex Elvmus Poa Agronvron Festuca Other grasses TOTAL GRAMINOIDS  7.7 29.6 49.4 0.0 0.0 (LO S O  9.0 13.9 26.8 3.6 3.1 0J) S O  12.6 26.3 29.9 0.0 0.0 0J) 6X7  7.7 19.3 16.4 4.4 2.3 CUD 5 0  7.2 23.3 36.9 0.0 0.0 3.2 7076  13.0 46.5 16.7 4.0 3.7 0.0 8X9  0.6 7 0  1.3 4(570  3.8 31.8 31.1 0.0 0.0 0.0 WJ  Artemisia Achillea Lupinus Dryas Astragalus Other forbs TOTAL FORBS  1373  0.0 0.0 3.0 0.0 12.3 14.7 3 0  2 0  0.0 30.4 2.9 2.0 0.0 3.0 3773  -  2.1 3.0 1476"  4.3 6.4 -  2973  0.0 0.0 2.3 0.0 2.0 7 . H77  27715  12.2 0.0 5.8 0.0 0.0 5.5 233  Conifers Other browse  0.0 0.0  1.5 2^9  0.0 3.4  2.1 5.0  0.0 0.0  07T5  3.3 0.4  3T7  0.0 10.3  T073  0.0 23.0  237TJ  0.0 0.0  07(7  5.5  0.0  0.7  0.8  3.0  0.0  TOTAL BROWSE  O  O  371  Lichen  0.0  9.2  0.0  771  4  A dash (-) indicates that the proportion of the food type i s lumped with others f o r that group.  Table 8.  Food habits o f Stone's sheep on unburned range i n northeastern B r i t i s h Columbia (1980-19821 determined by f e c a l analysis.  February 1982  March 23 April 21 1981 1981  May 13 1982  May 18 1981  May 22 1982  May 28 1980  June 5 1981  June 20 1981  June 25 1982 rams  June 25 1982 ewes  July 3 1980  July 12 August 1981 1980  Carex Elymus Poa Festuca Other grasses  3S.0 6.3 25.0 0.0 1.2  37.0 5.3 2.2 0.0 0.0  5.4 . 33.6 7.3 2.9 0.2  3.7 23.0 61.6 0.0 0.0  10.4 25.9 29.7 2.2 2.1  8.5 21.8 42.4 0.0 4.7  12.9  22.4 0.0 14.6 5.2 0.4  44.8  49.4  7.9 2.0 13.0 0.0 0.0  88.3  27.4 0.5 7.8 1.1 0.0  6.0  67.5  12.5 0.0 10.1 0.0 0.0  30.6  TOTAL GRAMINOIDS  12.8 0.0 10.0 1.5 2.9  70.3  77.4  63.4  27.2  42.6  22.6  22.9  48.3  36.8  53.6  Oxytroois Luninus Dryas Astragalus Other forbs  0.0 9.7 3.0 7.1 4.9  0.0 1.4 0.0 0.0 6.3  0.0 4.0 0.0 0.0 7.1  0.0 0.0 0.0 0.0 8.0  0.0 4.1 0.0 0.0 7.7  5.9 0.0 0.0 0.0 6.9  13.4  24.7  0.0 7.0 1.3 3.4 2.2  7.7  24.9 3.2 0.0 3.9 34.1  11.1  8.0  45.9 1.6 0.0 1.0 16.9  11.8  18.5  0.0 6.6 3.0 10.5 4.1  2.6 1.8  TOTAL FORBS  0.0 2.8 4.2 11.8 4.0  12.8  19.2  19.5  22.8  13.9  66.1  65.4  30.0  24.2  23.6  Conifers Salix Vaccinium Rosa Arctostaphylos Populus Other browse  0.0 0.0 0.0 0.0 0.0 0.0 0.9  1.5 1.8 1.8 1.0 1.1 0.0 1.9  3.5 2.0 2.0 3.2 2.3 0.0 4.0  0.0 0.0 0.0 0.0 0.0 0.0 1.5  0.0 0.0 0.0 1.9 2.2 0.0 4.0  0.0 0.0 0.0 0.0 0.0 0.0 4.5  0.0  12.0  0.0 8.1 0.0 0.0 0.0 0.0 1.0  20.3  0.0 5.5 0.0 0.0 0.0 0.0 3.0  1.5  14.7  4.4 14.6 4.8 1.5 2.5 2.7 4.1  0.0  0.9  1.7 17.7 6.5 1.7 2.1 4.3 8.5  0.0  TOTAL BROWSE  4.2 17.8 7.7 0.0 2.0 8.6 6.2  4.5  11.7  46.5  42.5  9.1  8.5  16.5  34.6  7.4  Lichen Mosses  6.9 0.0  35.5 0.0  15.6 3.6  2.2 0.0  3.2 0.0  5.3 0.0  5.4 0.0  3.5 0.0  1.0 0.0  2.2 0.0  3.2 0.0  5.2 0.0  3.4 1.0  15.4 0.0  3.2 2.9  A dash (-) indicates that the proportion of that food type i s lumped with others for that group.  7.1 4.4  69  variability  i n rumen s a m p l e s  from  different  A n o t h e r p r o b l e m was t h a t t h e f e c a l on  one p o o l e d  Therefore,  sample  from  a certain  animals.  a n a l y s i s was  collection  based  period.  t h e r e was no measure o f v a r i a n c e f o r t h e  samples. Given  these  significance data for  problems,  on s m a l l d i f f e r e n c e s  on f o o d h a b i t s . broad  i t would be unwise  Rather,  (i.e.,  t o p u t much  < 10%) i n t h e  I analysed  the data  p a t t e r n s i n the food h a b i t s throughout  looking the year.  WINTER FOOD HABITS Sheep u s i n g a l p i n e s l o p e s  i n winter  were f e e d i n g h e a v i l y on s e d g e s 21).  In the February  important in  both  whereas  samples, b l u e  t h e rumen a n d f e c a l  samples.  p a r t a n d browse b e i n g q u i t e  Sheep u s i n g b u r n e d , feeding (Poa) diet  with  primarily  ( P o a ) was v e r y  lichen  was v e r y  Overall,  high  g r a s s e s and  f o r b s making up a unimportant.  subalpine slopes  on r y e g r a s s  March)  ( T a b l e 8, F i g u r e  grass  i n t h e M a r c h sample  s e d g e s made up most o f t h e d i e t smaller  (Carex)  (February,  i n winter  (Elymus) and b l u e  were  grass  ( T a b l e 7 ) . F o r b s made up a s m a l l e r amount o f t h e a n d browse a n d l i c h e n  were u n i m p o r t a n t  food  items.  UNBURNED RANGE: winter alpine ~  100  lichen  E  80  ^  60 i  §  40  forbs grasses, primarily Poa  Carex  20  April subalpine lichen  May subalpine browse  forbs  forbs  browse  Elymus  June spruce-willow-birch Carex grasses, primarily Poa  Poa  other forbs Oxytropis  other forbs Lupinus  other browse  other browse  Salix grasses, p r i m a r i l y Poa  other grasses  Elymus  sunmer alpine  Salix  Carex  BURNED SUBALPINE RANQE: winter  3  80  forbs  1  other grasses. u.  60  o C  40  g  20  Figure 21.  Elymus  April  other forbs Achillea Carex  May  forbs other grasses  June  November moss other forbs Arternesia  Carex Elymus Poa  Elymus Poa  Poa  Elymus  Poa  Summary of seasonal food habits for Stone's sheep determined by fecal analysis on burned and unburned ranges in northeastern British Columbia (1980-1982). o  71  SPRING FOOD HABITS The  descent  clearings and  in A p r i l  lichen  grasses,  of sheep from was  e v i d e n t i n the d e c r e a s e  i n the d i e t  particularly  alpine areas to subalpine  and  t h e heavy use  E l y m u s , and  in  sedges  of s u b a l p i n e  browse s p e c i e s  including  conifers. The  onset  feeding  primarily  throughout sample that  o f new  May  (April  t h e most  on 22,  spring  on  new  growth r e s u l t e d  grasses  both burned 1982)  important  w h i c h began g r o w i n g  from  (Elymus  and  f o o d was  very e a r l y  yarrow  on  Movement t o h i g h e r e l e v a t i o n s with a decrease  i n g r a s s e s and  diet.  Locoweed  ( O x y t r o p i s ) was  food  item at t h i s  willows, on  at t h i s  shrubs.  willow early  an  time c o r r e s p o n d e d  June but  time of the y e a r . by  l a t e June t h e  altitudinal  limit  slopes.  range  One  indicated  (Achillea),  the s p r i n g  sheep  Poa)  a  forb  range.  i n J u n e was  associated  i n c r e a s e i n f o r b s i n the  t h e s i n g l e most  Heavy use  Sheep were o b s e r v e d  at t h i s  the upper  time.  and  natural  the burned  i n the  of s h r u b s , t o new  leaf  important  especially production  t o browse e x t e n s i v e l y P o p l a r s were u s e d s h e e p had  of p o p l a r s .  migrated  on  in above  72  SUMMER FOOD HABITS Sedges were t h e most alpine  summer r a n g e .  important  In a d d i t i o n ,  f o r b a n d browse s p e c i e s were a l s o major  food  i t e m o f s h e e p on  a wide a s s o r t m e n t o f taken.  f o o d s o u r c e a n d s h e e p were r e g u l a r l y  browsing  on w i l l o w s a t t h i s  time  Willows  were a  observed  of year.  F A L L FOOD HABITS I n f o r m a t i o n on f a l l sheep u s i n g burned,  food h a b i t s i s only a v a i l a b l e f o r  s u b a l p i n e range.  E l y m u s ) made up t h e b u l k o f t h e d i e t particularly  A r t e m i s i a were a l s o  Grasses  (Poa and  but f o r b s ,  eaten.  73  NUTRITIONAL INDICES OF The  sample v a r i a n c e f o r f e c a l  greatly feces,  reduced  by  correcting  that i s , c a l c u l a t i n g  n o n - a s h p o r t i o n of particularly licks  the  and  averaged  high ash content compared t o o t h e r  up  had  the p r o t e i n  content  t o 45%  i n a group of  samples  14-47%, c o r r e c t i n g  fecal  corrected  for  ash.  Figure  22  protein  shows t h e  Lowest va'lues  dramatic (30%)  i n the  protein  levels  fecal  v a l u e s by November.  a l p i n e range  i n February  varied  reduced  values  refer  protein  the  from  5.46  to  values  values  f o r sheep i n  t o sheep i n the Toad R i v e r  a l p i n e range  throughout  For  stated, a l l further  (10-12%) o c c u r r e d  were a t t a i n e d on  content  samples.  in winter  i n c r e a s e d u r i n g g r e e n - u p i n May.  gradually decreased winter  f o r ash  with  i n which ash c o n t e n t  fecal  t h e Y e d h e / D e l a n o a r e a compared area.  content  Therefore, unless otherwise of  mineral  low  f o r the ash c o n t e n t  s t a n d a r d d e v i a t i o n of the  discussion  t o 88%  mineral  Samples  variability  the  was  near  protein  be  the  (Table 9).  samples; c o r r e c t i n g  example,  of  of  This correction  abnormally  i n a much l o w e r  t o 3.46.  values could  i n samples c o l l e c t e d  resulted  on  protein  i n w h i c h f e c e s o f t e n c o n t a i n e d up  material  from  SHEEP  f o r the ash content  feces.  important  THE  Peak  in late  with values  J u n e and  t h e autumn r e a c h i n g  Fecal protein  values  were s i g n i f i c a n t l y  a  then  low  f o r sheep  greater  (P  74  Table 9. Seasonal changes i n fecal ash content of Stone's sheep on burned and unburned ranges i n northeastern B r i t i s h Columbia (1980-1982).  Delano/Yedhe area (X + SD) n  February  15.8 + 3.5  13  Toad Mountain area + SD) n  (K  12.1 + 0.9  8  March  -  15.5 + 5.5  11  early A p r i l  -  14.6 + 3.0  14  late A p r i l  -  16.9 + 4.6  8  12  16.4 + 7.2  12  16.9 + 2.1  5  early May  10.3 + 1.6  l a t e May  13.8 + 1.3 20.2 + 10.3*  5 9  early June  23.8 + 13.5*  16  45.9 + 14.9  3  late June  22.6 + 4.7*  20  21.9 + 10.0  4  early July  33.6 + 21.1*  10  -  late August  14.2 + 2.2*  November  -  * samples c o l l e c t e d at a mineral l i c k .  5  21.0 + 8.9  3  15.5 + 5.6  7  35  '1 i  1  J  l F  l M  i A  l M  J  i J  i A  l  l  1  S  O  i N  I  i  D  MONTH F i g u r e 22.  Seasonal p a t t e r n o f f e c a l p r o t e i n l e v e l s ( c o r r e c t e d f o r ash content) f o r S t o n e ' s sheep on burned and unburned ranges (X ± 95% C . I . ) i n n o r t h e a s t e r n B r i t i s h Columbia (1980-1982).  1 / 1  76  < 0.05) t h a n v a l u e s f o r s h e e p on t h e s u b a l p i n e range of F e r t i l i z e r surprising  because  f o o d compared values  Mountain. the a l p i n e  t o the subalpine  This  observation  range c o n t a i n e d range.  Fecal  from F e b r u a r y o f 1982 when t h e s h e e p  restricted  to a small,  heavily  r a n g e were n o t d i f f e r e n t  burned was  a l m o s t no protein  were  g r a z e d a r e a of t h e t o t a l  f r o m w i n t e r v a l u e s o f 1981 when  the e n t i r e  r a n g e was b e i n g u s e d .  from A p r i l  1982, when l a r g e a r e a s o f p r e v i o u s l y  unavailable  r a n g e became  were n o t s i g n i f i c a n t l y  Similarly  available  different  because  the values  o f snow m e l t ,  from t h e F e b r u a r y v a l u e s  when t h e s h e e p were c o n c e n t r a t e d i n a s m a l l a r e a . latter  two p o i n t s a r e c o n t r a r y  heavy g r a z i n g  results  The  to the hypothesis that  i n a decrease i n the q u a l i t y  of food  i n t a k e by t h e s h e e p . D u r i n g May, a l t h o u g h f e c a l increased dramatically it  appeared  that  s h e e p on b u r n e d valley than  protein  v a l u e s o f sheep  on b o t h b u r n e d a n d u n b u r n e d  t h e i n c r e a s e was 7-10 d a y s e a r l i e r f o r range.  V a l u e s f o r sheep  i n t h e Yedhe  on May 20, 1982 were s i g n i f i c a n t l y  t h e v a l u e s f o r sheep  earlier unburned  which range  range  on F e r t i l i z e r  demonstrates that  fecal  less  (P < 0.05)  Mountain  protein  two days  v a l u e s on  l a g g e d b e h i n d v a l u e s f o r sheep on b u r n e d  range.  Fecal  nitrogen  v a l u e s t h r o u g h o u t t h e summer  similar  i n b o t h p o p u l a t i o n s w h i c h was n o t s u r p r i s i n g  were  77  b e c a u s e b o t h p o p u l a t i o n s were u t i l i z i n g habitat  at that  DAPA v a l u e s relationships precluded  similar  alpine  time of the y e a r . (Figure  23) showed s i m i l a r p a t t e r n s and  to fecal protein  statistical  analysis.  but l a c k  of  replicates  Figure 23. Seasonal pattern of DAPA concentrations for Stone's sheep on burned and unburned ranges in northeastern British Columbia (1980-1982).  79  FOOD SELECTIVITY  SELECTION OF  SPECIES  There was  a l a r g e amount of v a r i a n c e i n both  e s t i m a t e s of food a v a i l a b i l i t y and  food h a b i t s which made  any a n a l y s i s of p l a n t s p e c i e s s e l e c t i o n Therefore,  the  difficult.  I r e s t r i c t e d the a n a l y s i s to major d i f f e r e n c e s  between use and  availability.  Species S e l e c t e d A g a i n s t L i c h e n s covered and  i n winter  up to 30% of a l p i n e ranges (Table  they sometimes became the only v e g e t a t i o n  a l p i n e ranges.  on  However, they u s u a l l y comprised o n l y a  very small p r o p o r t i o n of the d i e t  (about  5%).  T h i s small  amount c o u l d have been consumed a c c i d e n t l y while on sedges and  3)  forbs tangled in l i c h e n .  Dryas  feeding  integrifolia  and A r c t o s t a p h y l o s u v a - u r s i were the dominant ground cover p l a n t s on a l p i n e and 2 and  3).  subalpine areas  r e s p e c t i v e l y (Tables  However, they were only found  i n the d i e t  i n t r a c e amounts  (< 5%).  Sheep were not always on ranges with access c o n i f e r s but  to  i n s p r i n g when they were, c o n i f e r s were not  e x t e n s i v e l y used even though they were e s s e n t i a l l y u n l i m i t e d to any  sheep which chose to feed on them.  80  Betula the  range  heavily  g l a n d u l o s a was a b o u t  a s abundant a s w i l l o w s on  i n June b u t was n o t e a t e n whereas w i l l o w s were  used  at this  time  (Table 8 ) .  L u p i n u s a r c t i c u s was a common f o o d proportion on a l p i n e  i n the diet ranges  was f a r l e s s  (usually  ( T a b l e 8) b u t t h e  than  50-80% o f f o r b  its availability biomass).  Species Selected For The for on  o n l y s p e c i e s which  appeared  y e a r - r o u n d were Poa s p p . w h i c h s u b a l p i n e and a l p i n e  was s p a r s e l y spring  ranges  distributed.  selected  was an i m p o r t a n t  (Figure  21) even  At p a r t i c u l a r  a n d summer, v a r i o u s f o r b  and O x y t r o p i s were t a k e n  t o be h e a v i l y  food  though i t  times of the  species including  Achillea  f a r i n excess of t h e i r  availability.  SELECTION OF GRAMINOIDS Selection  f o r graminoids v e r s u s f o r b s d i d not d i f f e r  from a v a i l a b i l i t y appeared  VERSUS FORBS  on s p r i n g  t o be s e l e c t i o n  g r a m i n o i d s on a l p i n e  ranges  against  range  (Table 10).  forbs  i n summer.  There  i n favour of  81  Table 10. Proportion of forbs versus graminoids i n the diet of Stone's sheep compared to a v a i l a b i l i t y on the range.  Proportion of Diet {%) Graminoids  Burned subalpine, May  : Forbs  70  15  (4.7  Alpine, June-July  45 (1.5  1)  : 30 :  1)  Availability ( g / m ) Graminoids  : Forbs  20  5  (4  1)  5  : 10  (0.5 :  1)  82  SELECTION OF The  p r o t e i n content  b a s e d on and  SUPERIOR QUALITY FOOD  analyses  (uncorrected  data  f o r ash)  items  have an  Fecal  protein values  the  f e c e s of  sheep not  almost  t o the study  using  of the  were h i g h e r  food  than  fecal  quality  If  winter  24.  by a b o u t  lagged  10 d a y s .  to the  By  samples c o l l e c t e d  at  this hypothesis. t o be  food a v a i l a b l e  level  any  higher  the  animals  fecal  food  protein values levels.  f o r more p r o t e i n values  data d i d not i n t a k e of  range.  increase  i n c r e a s e i n food  i n p r o t e i n than  t o them on t h e  9).  protein  protein values  The  The  in  (Table  In s p r i n g t h e  the  the  random.  by  Fecal protein values  highly selective  than  to  fecal  15%  food p r o t e i n  should  have been h i g h e r  the  1973).  were r e d u c e d  summer, f e c a l  estimated  s h e e p were b e i n g  appear  (Hebert  estimated  behind  forage,  not  sheep  i s about  the  n u t r i t i o u s p a r t s of the  support  relationship  because the ash  vegetation.  protein values  were s i m i l a r  1:1  f o r a g e p r o t e i n v a l u e s when t h e  were f e e d i n g on in  in Figure  browse  b a s e d on  uncorrected  licks  T h e s e v a l u e s were compared w i t h content  f o r b s , and  Fecal p r o t e i n values  ( c o r r e c t e d f o r ash)  i n Hebert's  calculated  i n the d i e t  of mountain  t o make them c o m p a r a b l e levels  i n t a k e was  grasses,  (Figure 24).  p r o t e i n i n the d i e t  protein  food  of  these  crude  15%  the  the p r o t e i n content  the p r o p o r t i o n of  fecal  of  of  appear  the the  forage to  sheep d i d average  83  UN BURNED  RANGE  28T  l April  i May  • June  July  MONTH  Figure 24.  Relationship between protein concentrations of the available forage and the fecal protein concentrations of Stone's sheep (standardized to 15% ash content).  84  MINERAL NUTRITION  SOIL MINERAL CONCENTRATIONS Soil Total  mineral  concentrations are presented  n i t r o g e n c o n c e n t r a t i o n s were lower  slope areas  (Yedhe, D e l a n o ) t h a n  more s t a b l e a r e a s . spring  r a n g e by s h e e p i n t h e s e  carbon:nitrogen ensure  These t a l l u s  ratios  occurring  Lupinus, indicated  were low enough t o  1978).  However s o i l  (< 1 ppm).  p l a n t s i n the area  a soil  deficient  low n i t r a t e  of  nitrification  in available  legumes) a l s o nitrogen  c o n c e n t r a t i o n s may r e s u l t characteristic  and O f f n e r  of c o l d ,  from  even high.  low r a t e s  subarctic  soils  1982).  P h o s p h o r o u s c o n c e n t r a t i o n s were e x t r e m e l y soils  except  other  nutrient concentrations  forFertilizer  t o be s e v e r e l y l i m i t i n g  P, K) t e n d e d  The abundance  n i t r o g e n c o n c e n t r a t i o n s were r e a s o n a b l y  The  p e r s . comm.).  nitrate  (Shepherdia,  O x y t r o p i s , A s t r a g a l u s and other  though t o t a l  (Mitchell  The  i n n i t r o g e n m i n e r a l i z a t i o n was  (Thompson and T r o e h  nitrogen-fixing  from t h e  s l o p e s were u s e d a s  two a r e a s .  c o n c e n t r a t i o n s were u n d e t e c t a b l e of  11.  i n t h e two t a l l u s  i n the s o i l s  i n a l l the s o i l s  that a net gain  i n Table  mountain.  t o be h i g h e r  soil  Otherwise,  a l l the  ( C a , Mg, K) were n o t l i k e l y  t o p l a n t growth  The m a j o r  low i n a l l  (T. B a l l a r d  n u t r i e n t c o n c e n t r a t i o n s (N,  on F e r t i l i z e r  Mountain  than  from  Table 11. Mineral concentrations and pH o f s o i l s and mineral l i c k s i n the Toad River area.  pH  total N %  C  C:N  %  P  Ca  Mg  K  Na  S  ppm  ppm  ppm  ppm  ppm  ppm  Yedhe  7.5  0.10  1.17  11.7  u  3026  73.0  39.0  u  -•  Delano  6.0  0.08  1.43  17.9  u  1202  145.9  78.0  u  -  Tower  6.2  0.44  1.81  4.1  u  2645  340.5  78.0  u  -  Magnum  7.0  0.89  16.25  18.3  2.1  8958  681.0  78.0  u  -  Fertilizer  6.8  0.52  3.23  6.2  16.6+3.1*  3968  425.6  117.3  u  0.4+0.3  4.8+6.5  11.6+6.5  X  + SD  6.7+0.6  3959+2965 333+241 78.0+27.6  u  7.5+1.2*  -  Mineral Licks: C h u r c h i l l mine  8.1  0.01  0.10  10.0  u  3387  133.8  117.3  92.0  -  Toad Bridge  8.8  0.08  0.72  9.0  u  3447  1252.4  39.0  23.0  -  Toad Mountain  7.6  0.12  0.67  5.6  u  4329  389.1  39.0  23.0  -  8.2+2.,3  u  3721+527 592+586  65+45  46+40  -  X - SD *  8.2+0.6  0.1+0.06 0.5+0.3  Y - SD, n=8  u = undetectible, less than 0.1 ppm f o r phosphorus and less than 23.0 ppm f o r sodium.  86  other s i t e s which suggested  that the frequent burning i n  t h i s area had no d e t r i m e n t a l e f f e c t on s o i l n u t r i e n t s and may even have been b e n e f i c i a l .  FORAGE MINERAL CONCENTRATIONS Forage m i n e r a l c o n c e n t r a t i o n s are compared t o the m i n e r a l requirements et a l . 1979) i n Table  of domestic 12.  sheep (NRC 1975, Maynard  These v a l u e s a r e f o r  m a i n t a i n i n g sheep i n good c o n d i t i o n and probably the needs f o r b a s i c s u r v i v a l .  Winter forage was d e f i c i e n t  in n i t r o g e n , phosphorous, potassium, copper.  Sulphur  exceed  z i n c , and p o s s i b l y  l e v e l s were low but probably  adequate  c o n s i d e r i n g the low n i t r o g e n intake a t t h i s time.  Levels  of c a l c i u m , magnesium, i r o n , and manganese were adequate to meet the the requirements  of sheep.  L e v e l s of the f i v e  d e f i c i e n t m i n e r a l s , p a r t i c u l a r l y potassium, higher i n the subalpine winter  tended  t o be  forage than the a l p i n e  forage but the data a r e too scant f o r s t a t i s t i c a l comparisons. New s p r i n g grasses from a l l s i t e s met or came q u i t e c l o s e to sheep requirements slightly  f o r a l l minerals  low i n z i n c and s u l p h u r ) .  (Delano was  The c a l c i u m :  phosphorous r a t i o was a l s o c l o s e t o the optimum of 2:1. Similarly,  summer grasses and sedges c o n t a i n e d adequate  l e v e l s of a l l m i n e r a l s except phosphorous.  The sedges  Table 12. Mineral concentrations i n forages from Stone's sheep ranges i n northeastern B r i t i s h Columbia (1980-1982) compared to requirements of domestic sheep.  P  Ca  Mg  K  %  %  %  0.73 0.58  0.09 0.07  0.83 0.83  0.11 0.75  0.40 0.52 0.58  0.04 0.06 0.03 0.04  0.73 0.70 0.71 0.71  3.43 2.92 3.50 3.28  0.27 0.31 0.27  N  Fe ppm  Zn ppm  Mn ppm  Al ppm  0.43 0.54  63.0 28.0  17.0 18.0  24.0 5.0  50.0 20.0  6.0  0.90 0.85 0.95 0.90  0.18 0.12 0.09 0.13  63.0 43.0 64.0 56.7  5.0 11.0 9.0 8.3  74.0 16.0 38.0  60.0 30.0 60.0  1.0 1.0 1.0  42.7  30.0  0.13 0.13 0.17 0.14  2.45 2.78  -  2.62  119.0 112.0 140.0 123.0  15.0 35.0 61.0 37.0  43.0 49.0 37.0  0.28  0.77 0.46 0.50 0.58  2.50 2.40  0.20 0.18  0.47 0.34  0.17 0.17  1.76 1.96  160.0 60.0  F e r t i l i z e r mountain Yedhe creek Delano Mean  1.90 2.30 2.20  0.23 0.14 0.17  0.18  0.43 0.48 0.30 0.40  0.11 0.15 0.12  2.60 2.65 3.55  48.0 37.0 46.0  0.13  2.93  Alpine Salix (June)  3.60  0.31  0.75  0.30  SHEEP REQUIREMENTS:  1.60  0.25  0.25-0.50  0.06  %  Subalpine winter  %  Cu ppm  B ppm  S X  forage:  F e r t i l i z e r mountain Toad mountain  3.0  7.64 7.52  0.11  1.0  5.70 5.20 5.40 5.40  0.09 0.09 0.10  8.0 6.0 8.0  5.50 7.80 4.80  43.0  190.0 130.0 190.0 170.0  7.3  6.00  0.11 0.21 0.24 0.19  55.0 26.0  34.0 61.0  60.0 10.0  111.0 2.0  8.80 6.40  0.22 0.21  43.7  25.0 11.0 9.0 15.0  20.0 36.0 53.0 36.3  10.0 10.0 20.0  13.3  4.0 4.0 6.0 4.7  4.10 4.40 4.70 4.40  0.15 0.18 0.17 0.17  1.43  188.0  101.0  31.0  333.0  8.0  20.00  0.30  0.50  25-40  20-30  16-40  0.0  5.0  0.0  0.18  0.09  Alpine winter forage: Delano Toad Magnum Mean  0.50  0.09  Subalpine spring range: Delano F e r t i l i z e r mountain Magnum Mean Alpine range (July): Magnum creek Tower mountain Subalpine range (July):  2.13  oo  88  from Magnum V a l l e y w i t h  the  were c o l l e c t e d  t o the abandoned copper  Summer w i l l o w  adjacent  leaves contained  sheep requirements  BEHAVIOUR AT Use April  of the  sites,  quickly  but  licks use  by  of a l i c k  including  until  the  approaching  lick.  licking  At  and  allowing  The  the  people  The  intensity  i n the  this  contained  averaged spent  up  from  rest. usually  Most no  up  lick  level  t o 88% 9).  hours l i c k i n g  licking  licked  use  t h a t the  (Table  took  observed  to get  became o b s e s s e d  i n a mouthful of  fact  t o 45% 1-4  mine, d u r i n g much o f  a strong determination  sheep e i t h e r  reflected  also  from s e v e r a l k i l o m e t r e s away i n  the animals  of m i n e r a l  from  s h e e p from u s i n g many  metres the  with  f e c e s of  before  ground  soil  during  mineral  to  of c a u t i o n , o f t e n  t o a p p r o a c h w i t h i n 2-3  t o n g u e o r took  time  exceeding  primarily  Sheep were o f t e n  a lick  lick  the  e x h i b i t e d a reduced  moving away. their  mine.  i n November was  Churchill  l a t e May.  a manner w h i c h s u g g e s t e d the  levels  sheep o c c u r r e d  Deep snow p r e v e n t e d  winter  in July  MINERAL LICKS  to J u l y  the  mineral  levels  for a l l minerals.  of m i n e r a l  observed.  high copper  and  the  with  chewed i t .  summer  was  some s h e e p d u r i n g  material  and  I n d i v i d u a l sheep u s u a l l y b e f o r e moving o f f t o f e e d  p l a c e d u r i n g mid-day.  sheep at the C h u r c h i l l  mine e a r l y  in  or  T h e r e were the  89  morning but they area  by 1800.  began t o move  The f r e q u e n c y  i n about  0800 a n d l e f t t h e  o f use o f l i c k s  by  individual  s h e e p i s n o t w e l l known b u t o f 6 c o l l a r e d  sheep u s i n g the  Churchill  individuals  ranged  lick,  from  frequency  o f u s e by known  1 t o 6 d a y s o u t o f a 10-day o b s e r v a t i o n  period  o r an a v e r a g e u s e o f once e v e r y  2-3 d a y s .  sheep i n s u b a l p i n e a r e a s  t h e summer were u s u a l l y  related  t o the animals  Sheep were o b s e r v e d to  use t h e l i c k  Alaska  during  using  S i g h t i n g s of  subalpine mineral  m o v i n g q u i c k l y down  from a l p i n e  on T o a d M o u n t a i n and a t M i l e  Highway b u t t h e y  then  returned  licks. areas  475 o f t h e  to alpine  areas.  MINERAL LICKS Many d i f f e r e n t  forms o f m i n e r a l  the area  including:  and  c u t s , i i ) weathered, rocky  road  man-made s o u r c e s , site  and m i l l  created of  licks  particularly  site.  exposed a l o n g outcrops,  the C h u r c h i l l  On T o a d M o u n t a i n  a s m a l l cave e x t e n d i n g  were u t i l i z e d i n  about  creek  beds  and i i i ) copper  mine  t h e s h e e p have 1.5 m i n t o  the side  t h e m o u n t a i n by e a t i n g t h e s o i l . Soil  nitrogen due  1) s o i l  licks  from m i n e r a l and carbon  licks  levels  (Table than  11) had l o w e r  other  t o the l a c k of o r g a n i c matter.  expected without  value  f o r calcium carbonate  the a c i d i f y i n g  effects  soils  i n the area  The h i g h e r mineral  total  pH i s t h e  material  of o r g a n i c a c i d s p r e s e n t i n  90  other s o i l s .  L e v e l s of phosphorous, c a l c i u m , magnesium,  and potassium  were not d i f f e r e n t  from the a r e a .  Soil  only element which was  i n forage samples. higher  which suggests  that i t was  these areas  Sodium was  the samples except The  samples  l e v e l s of these elements were  than the l e v e l s found  .  from other s o i l  Sodium was  in mineral l i c k  (< 23 ppm)  f o r the three m i n e r a l l i c k  the  samples  the m i n e r a l a t t r a c t i n g undetectable  lower  sheep to in a l l  samples.  sheep a l s o became f r a n t i c i n t h e i r e f f o r t s to get  access to the s a l t  b l o c k s we used as b a i t f o r t r a p p i n g  i n d i c a t i n g a strong d r i v e to o b t a i n sodium.  91  FORAGING  BEHAVIOUR  BITING RATE  Daily  Pattern  On t h e 2 o c c a s i o n s of  individual  hours, there  in April  ewes was o b s e r v e d was no t r e n d  1982 when t h e b i t i n g throughout  i n the b i t i n g  throughout  t h e day o r d u r i n g  Therefore,  I concluded  that  foraging  b u t r a t h e r a sample a t a n y of the b i t i n g  rate  the day.  a n d Age D i f f e r e n c e s On t h e one day when t h e b i t i n g  yearlings difference ±  bouts.  i t was n o t n e c e s s a r y t o  t i m e o f t h e day w o u l d be r e p r e s e n t a t i v e  Sex  the daylight  rate either  individual  conduct day-long observations  throughout  rate  1.8  was d e t e r m i n e d , t h e r e  was no  significant  (P < 0.05) between t h e b i t i n g  (S.E.) b i t e s / m i n u t e ) ,  bites/minute), feeding  r a t e o f rams a n d  yearlings  a n d ewes (34.2 ± 2.4  on t h e same r a n g e .  r a t e o f rams (30  (30 ± 1.2  (S.E.)  (S.E.)  bites/minute)  92  Seasonal The  Pattern biting  throughout of  rate  remained  t h e spring-summer  r a n g e t y p e s and f o r a g e  relatively  s e a s o n under a wide v a r i e t y  distributions  was no d i f f e r e n c e between t h e b i t i n g burned versus n a t u r a l appeared that  subalpine  (Table  rate  spring  biting  and  this  rate averaging  about  r a t e was n o t o b v i o u s l y  13).  There  o f s h e e p on  range.  Stone's sheep m a i n t a i n e d a  constant that  constant  Overall i t  relatively  30-35  bites/minute  a f f e c t e d by t h e r a n g e  characterist ies.  FORAGING The  TIME proportion  remained constant  of d a y l i g h t throughout  hours spent  the winter-spring  b o t h e w e / y e a r l i n g g r o u p s a n d ram g r o u p s 15). of  On a v e r a g e , e w e / y e a r l i n g  the daylight  proportion day  hours f o r a g i n g  of time  spent  t o d a y f o r rams t h a n  foraging  f o r ewes/yearlings.  t i m e was o n l y  year.  These data  13% more  Also the from  The one  (May 19) when  50% may have been due t o a  p r e p o n d e r a n c e o f y e a r l i n g s on t h a t  f r o m t h e main s l o p e  14 a n d  was more v a r i a b l e  foraging  distortion  (Tables  t h a n d i d rams.  day o f e w e / y e a r l i n g a c t i v i t y  This  period f o r  groups spent about  atypical  ewes).  foraging  day (6 y e a r l i n g s , 2  was c a u s e d by a d u l t  t o lambing c l i f f s  represent  ewes moving  at this  time of  a wide r a n g e o f c o n d i t i o n s  93  Table 13.  Date  B i t i n g rate of Stone's sheep ewes under d i f f e r e n t range c h a r a c t e r i s t i c s (April-June).  B i t i n g Rate  April 9  35.0  A p r i l 20  26.0  May 5  28.0  May 11  29.4  May 13  34.8  May 20  34.2  May 22  34.8  May 24  31.8  June 28  37.7  +  +  +  +  +  +  +  +  +  Number o f observations*  Range Type  Forage Biomass  Grass T i l l e r Length  2 (g/m )  cm  1.2  44  subalpine burn  162 dead  -  0.6  90  subalpine burn  162 dead trace l i v e  -  1.0  22  subalpine burn  14 l i v e grass  8  1.2  35  subalpine burn  14 l i v e grass  9  2.6  11  subalpine clearing  1.5 l i v e grass  10  1.5  24  subalpine burn  20 l i v e grass  13  1.7  12  subalpine clearing  1.6 l i v e grass  11  2.2  11  subalpine burn  34.2 grass 15.4 forbs  13  1.2  15  alpine  3.7 sedges 13.5 forbs  12  1 observation equals a 1-2 minute period o f observation.  Table 14.  Date  Time budget and calculated bites/day for Stone's sheep ewes and yearlings (February-May).  Number o f observations  PERCENTAGE OF DAYLIGHT TIME Resting %  Travelling 4  Foraging %  Standing 1  Observation period (hours)  Daylight hours foraging  Estimated bites/day  Feb. 8 Feb. 14  1907 1767  17.5 21.0  2.7 2.0  62.6 67.0  17.7 10.0  10 10  6.2 6.7  9600 10375  March 16  1965  32.0  2.0  62.0  4.0  12  7.4  13480  March 17  1807  21.0  5.0  67.0  6.0  12  8.0  14573  March 18  1677  21.0  7.0  69.0  4.0  12  8.2  14940  March 24  2341  24.0  4.0  70.0  3.0  13  9.1  16580  March 31  1696  27.0  1.0  64.0  8.0  13  8.3  15123  April 4  1744  34.0  2.0  60.0  4.0  14  8.4  15305  70  30.0  5.0  61.0  4.0  14  8.5  15487  May 5  2859  26.0  4.0  64.0  5.0  16  10.2+  18584+  May 7  954  29.0  4.0  61.0  6.0  17  10.4+  18950+  May 10  2322  30.0  3.0  63.0  5.0  18  11.3+  20590+  May 12  1925  25.0  6.0  60.0  9.0  18  10.8+  19675+  A p r i l 20  May 12*  918  30.0  1.0  63.0  5.0  18  11.3+  20590+  1465  42.0  2.0  50.0  6.0  18  16400+  May 25 935 Mean Standard Deviation  32.0 26.6 4.4  1.0 3.3 1.9  64.0 63.8 3.1  3.0 6.3 3.8  18  9.0+ 11.5+  May 19**  20955+  sheep on natural subalpine clearing, a l l other data i s for sheep on subalpine burned range. ** predominately yearlings — dashed line separates periods of feeding on senescent forage from periods of feeding on new production.  Table 15.  Date  Time budget and calculated bites/day for Stone's sheep rams (February-May).  Number of SrvaSons  PERCENTAGE OF DAYLIGHT TIME Resting  Travelling  Foraging  Standing  Observation Period  Daylight hours foraging  Estimated bites/day  Feb. 8  410  34.6  2.8  40.0  21.2  10  4.0  6195  Feb.  547  41.0  2.0  56.0  1.0  10  5.6  8673  14  Feb.  204  56.0  5.0  37.0  3.0  12  4.4  6814  16  298  34.0  6.0  46.0  14.0  12  5.5  8518  505 505  4 Z.U 42.0  1.0 I.U  49.0 H .U  8.0 „ .„  14  6.9  58.0  10.0  16  9.3+  Feb. 17 April 4 May 5 -  •  4.0 ,  3  12572  1586 ----  28.0  401  42.0  4.0  49.0  5.0  18  8.8+  16035  38.0  1.0  56.0  5.0  18  10.1+  18402+  34.5  2.5  56.9  6.0  18  10.2+  18584+  38.0  3.0  54.0  4.0  18  9.7+  17675+  38.0  2.0  53.0  7.0  18  9.5+  17300+ 18950+ 16400+  n  C  D  n  1  n  n  l f i  g  3  +  1  May  9  May  10  May  12*  May  12  May  19  231  May  19  248  35.0  4.0  58.0  3.0  18  10.4+  May  25  1461  39.0  4.0  50.0  7.0  18  9.0+  38.0  3.2  51.0  7.3  2150 362 1885  Mean Standard Deviation  6.7  1.5  6.8  6  9  4  5  +  5.4  * c W n on natural subaloine clearing. A l l other data i s for sheerj on subalpine burned range. o/feeding on senescent forage from periods of feeding on new production.  -- S£ nSiyS^SriS  96  i n c l u d i n g c r a t e r i n g through the snow i n February, snowf r e e slopes with dead grass  i n March-April  and new  production  i n May.  S i m i l a r l y , there was no d i f f e r e n c e i n  proportion  of time spent f o r a g i n g between sheep feeding on  subalpine  burned range and sheep feeding on a n a t u r a l  subalpine  c l e a r i n g i n May.  The  p r o p o r t i o n of d a y l i g h t hours spent  remained constant  even though the amount of d a y l i g h t  almost doubled from February t o May. the winter  foraging  I t appeared that i n  the sheep were not f o r a g i n g during darkness and  thus the o b s e r v a t i o n  p e r i o d i n c l u d e d a l l or most of the  t o t a l time spent f o r a g i n g .  This conclusion  i s based on  the f a c t that the sheep were u s u a l l y seen bedding down i n the evening and were o f t e n seen bedded i n the same spot the f o l l o w i n g morning.  In f a c t ,  i n winter  the sheep o f t e n  remained bedded down f o r up t o an hour a f t e r l i g h t was adequate to begin observation  observations.  In s p r i n g , the  p e r i o d d i d not i n c l u d e the e n t i r e day's  foraging a c t i v i t y f o r a g i n g before  s i n c e most of the sheep u s u a l l y began  l i g h t was adequate t o see them.  most sheep u s u a l l y had bedded down before prevented f u r t h e r o b s e r v a t i o n continued  darkness  some f o r a g i n g  beyond the o b s e r v a t i o n  period.  Although  still  The occurrence  of a major f o r a g i n g bout a t dawn and dusk i n c o n j u n c t i o n with bedding a c t i v i t y a t dusk suggested that  extensive  97  f o r a g i n g d i d not occur d u r i n g the s e v e r a l darkness  i n the spring.  definitely spring  Thus, the o b s e r v a t i o n p e r i o d  d i d not i n c l u d e  the e n t i r e  b u t p r o b a b l y came c l o s e  f o r e w e / y e a r l i n g g r o u p s went  February  t o 12+ h o u r s  a l l of the f o r a g i n g  feeding, p a r t i c u l a r l y period The  was  4-5  i n May.  t i m e was  spent  actively  i n w i n t e r when much o f t h e f o r a g i n g  spent d i g g i n g  t h r o u g h snow  ( F i g . 25) and a v e r a g e d  1982.  In a d d i t i o n ,  foraging  t o reach the food.  time and a c t i v e observations  spent  feeding with the  s e a r c h i n g , chewing, e t c .  on t h e d i f f e r e n c e  biting  time determined  by r e d u c i n g t h e f o r a g i n g  t o account foraging  between  foraging  during biting  rate  (n = 2 6 4 ) .  numbers o f b i t e s / d a y i n T a b l e s  calculated  feeding  t h e y e a r o n l y 92% o f t h e  t i m e was s p e n t a c t i v e l y  T h i s v a l u e i s based  The  15 - 20% d u r i n g F e b r u a r y o f  throughout  r e m a i n i n g 8% o f t h e t i m e  of  6.2 h o u r s i n  amount o f t i m e s p e n t d i g g i n g was d e p e n d e n t on t h e snow  depth  15%  spent  and f o r rams went f r o m  i n F e b r u a r y t o 10+ h o u r s  Not  from  period in  f o r a g i n g d i d not  The t i m e  foraging  i n May  foraging  i f in fact  o c c u r d u r i n g t h e peak o f d a r k n e s s .  hours  hours of  for cratering  time.  then m u l t i p l i e d  The r e s u l t a n t  time  and t h e n  t i m e by an a d d i t i o n a l  14 a n d 15 were i n F e b r u a r y by  reducing a l l values  8% t o a c c o u n t  values f o r feeding  by t h e a v e r a g e  biting  r a t e o f 33  f o r nontime  was  99  bites/minute.  LENGTH AND  NUMBER OF FORAGING BOUTS  Detailed showed t h a t throughout  day-long  o b s e r v a t i o n s o f two ewes  b o t h a n i m a l s had f o u r t h e day r a n g i n g from  240 m i n u t e s  s e p a r a t e d by r e s t  150 m i n u t e s .  In both a n i m a l s  began b e f o r e d a y l i g h t into  the darkness.  bouts of  foraging  60 m i n u t e s  in April  bouts t o g r e a t e r than  p e r i o d s r a n g i n g from the f i r s t  and t h e l a s t  foraging  foraging  bout  40 t o  bout continued  Therefore, the exact d u r a t i o n of these  i s unknown.  In b o t h c a s e s t h e l o n g e s t f o r a g i n g  t h e day (160+ and 240+ m i n u t e s )  was  bout  t h e one p r e c e d i n g  darkness. The  time  budget  data  rams showed a s i m i l a r throughout  May  lumped f o r e w e s / y e a r l i n g s a n d f o r  p a t t e r n of four  ( F i g . 26).  However,  o n l y had t h r e e f o r a g i n g  of  showed m a j o r dawn and dusk  the d i f f e r e n c e The  fact  that  the aggregated deal  26 t h a t  group. behaviour  bouts/day.  Both  f e e d i n g bouts  of i n t e r v e n i n g  that  i n the behaviour However,  with  even i n  t h e r e was a g r e a t  of animals w i t h i n a  i t c a n a l s o be seen  from F i g u r e  o f rams compared t o e w e s / y e a r l i n g s  asynchronous,  times  bouts.  the p a t t e r n i s q u i t e d i s t i n c t  data demonstrates  of synchrony  foraging  often  b e i n g t h e number  bouts/day  i n F e b r u a r y and M a r c h ,  the animals the year  foraging  w i t h rams f e e d i n g w h i l e t h e  was  100  MARCH 17,  EWES  • • 1107  MARCH 17.  TIME  OF  DAY  RAMS  Is  211  OrO  standing and travelling  resting  foraging  Figure 26.  Typical daily time budgets of Stone's sheep ram groups compared to ewe/yearling groups in March and May.  101  ewes/yearlings were r e s t i n g e t c .  1 02  PARASITOLOGY Lungworm samples  l a r v a e counts f o r winter and s p r i n g  fecal  are presented i n Table 16.  Most l a r v a e belonged to P r o t o s t r o n g y l u s spp. but i n a d d i t i o n some samples  c o n t a i n e d up t o 33 larvae/gram of  d o r s a l - s p i n e d l a r v a e , most l i k e l y spp.  (W. Samuel, p e r s . comm.).  u s i n g unburned  range  Muellerius  Lungworm counts from  (Delano) were higher than  sheep  samples  from burned subalpine range i n both winter and s p r i n g . However, the high s p r i n g count f o r the Delano  samples  probably r e s u l t e d from a b u i l d - u p o c c u r r i n g on the a l p i n e winter range rather than r e f l e c t i n g on the q u a l i t y of the s p r i n g range.  In both areas the s p r i n g counts were higher  than the winter counts i n d i c a t i n g that p a r a s i t e loads c o n t i n u e d to b u i l d up throughout the w i n t e r .  103  Table 16.  Prbtbstrbngylus larvae counts i n feces o f Stone's sheep on burned and unburned range i n northeastern B r i t i s h Columbia (1982).  number o f larvae/g feces X  SE  417  171  38  10  Delano subalpine, May  824  567  F e r t i l i z e r subalpine, May  220  71  Location and Season  Delano alpine, February" F e r t i l i z e r subalpine, February  range  n  34-992  17-65  192-3087  42-385  4  1 04  HORN GROWTH OF RAMS The during  maximum i n c r e m e n t  t h e second year of l i f e  subsequently of  declined  t h e r e was no d i f f e r e n c e in yearling  difference  in total  to burned  burned  reporting compared  to nullify  have l o n g e r  for yearlings  ages.  range  advantage  Despite this  ( F i g . 2 8 ) . The  by s h e e p  f r o m an i n c r e a s e d  from rate of  i s e s t i m a t e d by r e c o r d e r on (58.5 mm ± 12.3 ( S . E . ) )  range  (30.8 mm ± 7.9 ( S . E . ) ) .  was n o t s t a t i s t i c a l l y  between r a n g e s .  horn.  t o unburned  t o rams on u n b u r n e d  sufficient  growth  l e n g t h between rams w i t h a c c e s s  form) i n t h e s e a n i m a l s  This difference  Horn  t h e r e was no s i g n i f i c a n t  to result  (amount broomed  27).  range  for older  horn growth  range appeared  brooming  because  horn  occurred  r a n g e was s i g n i f i c a n t l y  growth,  r a n g e compared  loss of the e a r l y  was  w i t h age ( F i g u r e  (P < 0.05) t h a n on u n b u r n e d  difference  length  ( a n n u l u s 1-2) a n d  rams w i t h a c c e s s t o b u r n e d  greater but  i n ram h o r n  significant  the d i f f e r e n c e  i n horn  A l t h o u g h rams f r o m b u r n e d  but i t growth  range d i d not  h o r n s , t h e y may have s c o r e d h i g h e r a s t r o p h i e s  the thin  t i p was n o t i n c l u d e d  i n the remaining  2201 200-  •  BURNED  •  UNBURNED  RANGE RANGE  180-  E E  Hi  5 UJ QC O  1601401201008060-  QC O  4020-  10  HORN Figure 27.  ANNULUS  Comparison of annual horn increments of Stone's sheep rams on burned versus unburned range (X ± 95% C.I.) in northeastern British Columbia (1980-1982).  o  HORN Figure 28.  ANNULUS  Comparison of horn lengths from tip to annulus of Stone's sheep rams shot on burned range and unburned range (X ± 95% C.I.) i n northeastern British Columbia (1980-1982).  o ON  107  POPULATION  POPULATION The  PARAMETERS  NUMBERS  f o l l o w i n g p o p u l a t i o n numbers a r e minimum  In a d d i t i o n , b e c a u s e most o f t h e a r e a habitat,  on  was c o n t i n u o u s  any b o u n d a r y u s e d t o d e f i n e a p o p u l a t i o n  have been q u i t e The  counts.  the subalpine  a r e f o r t h e number  slopes of F e r t i l i z e r  T h i s group appeared  t o be d i s c r e t e  of sheep w i n t e r i n g Mountain  from o t h e r  (Table 17). wintering  g r o u p s and t h e numbers r e m a i n e d q u i t e c o n s t a n t the  winter.  the  snow m e l t e d  and a n i m a l s  Toad Mountain found  c o u l d move a r o u n d more  i n the winter,  f r o m 5-16  22 a n i m a l s  and s p r i n g  s h e e p on t h e s u b a l p i n e  surveys  14-17 s h e e p on a d j a c e n t  of t h e Sulphur  a l p i n e peaks.  counts  slopes.  Creek area  found  In a d d i t i o n ,  were s p o t t e d on o t h e r m o u n t a i n s  Toad R i v e r a r e a  t h a t were n o t i m m e d i a t e l y  burned  Overall,  slopes.  easily.  15-20 sheep u s e d t h e a l p i n e p e a k s o f  Winter a e r i a l  another  throughout  However, numbers were q u i t e v a r i a b l e a f t e r  Approximately  usually  would  arbitrary.  best counts  adjacent  sheep  adjacent  the Toad R i v e r / S u l p h u r  i n the to  Creek  area r  supported  at least  f o r a minimum  90 s h e e p i n an a r e a  density estimate  of about  o f 1 sheep/10  900  km . 2  km  2  10  Table 17. Maximum d a i l y count of sheep on F e r t i l i z e r Mountain each month (1980-1982).  Total  Yearlings  Rams  8  7  12  27  March 1981 A p r i l 1981 May 1981  11 11 16  6 8 8  9 5 16  26 24 40  February 1982 A p r i l 1982 May 1982  16 16 14  8 8 7  9 9 6  33 33 27  A p r i l 1983  19  8  15  42  Date  May 1980  Ewes  109  Winter a e r i a l  surveys  f r o m 40-50 a n i m a l s in Delano v a l l e y  i n the Yedhe/Delano a r e a  on windswept a l p i n e r i d g e s .  ranged  from 25-40 a n i m a l s .  (June-July)  at the C h u r c h i l l  opportunity  to obtain  mine s i t e  replicate  May c o u n t s  Summer  provided  counts over  located  counts  the best  many d a y s  (Table 18). In  1982 e i g h t c o l l a r e d  mineral  lick  sheep r e g u l a r l y  b u t on a n y one d a y o n l y  would be s p o t t e d a t t h e l i c k .  total  on any d a y p r o b a b l y  of  the t o t a l  was  likely  during  that a t o t a l  t h e summer.  animals The  number o f a n i m a l s  only  area  provided  the l i c k .  25-65%  Thus, i t  o f 100-125 s h e e p u s e d t h i s  The s i z e  of adjacent  sheep appeared  Therefore, the  i n c l u d e d from  using  of the area  were drawn t o t h i s m i n e r a l  total  this  2-5 o f t h e s e  individuals count  used  watersheds  t o be c o m i n g t o t a l e d  a rough e s t i m a t e  lick  from  which  was n o t known.  from w h i c h  about  o f 1 sheep/7-8  lick  these  800 km . 2  This  km . 2  LAMB AND YEARLING COUNTS It  was d i f f i c u l t  Toad R i v e r area the  to obtain accurate  b e c a u s e by t h e t i m e t h e lambs were  s h e e p were i n s m a l l  spruce-willow-birch (short  groups d i s p e r s e d widely  zone.  M o u n t a i n were  i n the born  i n the  C o u n t s o f 9-month-old  y e a r l i n g s ) on F e r t i l i z e r  more r e l i a b l e  lamb c o u n t s  lambs  probably  due t o t h e d i s c r e t e n e s s o f t h e p o p u l a t i o n  110  Table 18. Number o f sheep using C h u r c h i l l mine l i c k and adjacent areas i n summer (1980-1982) .  Date  Number  June 1980  52  July 1980  49  June 1981  36-49  July 1981  39-102  June 1982  24-76  111  and  the  opportunity  to obtain  replicate  also d i f f i c u l t  to obtain  lambing  Delano/Yedhe a r e a ,  i n the  problems. the  The  most r e l i a b l e  summer a t  were  lamb c o u n t s  t h e mine s i t e  counts.  It  immediately  after  p r i m a r i l y due  to  c o u n t s were t a k e n  was  access  later  where l a r g e , r e p l i c a t e  in  samples  obtained. In  1980  the  Fertilizer early  lamb/ewe r a t i o  M o u n t a i n and  spring with (Table  almost  times  four  Churchill burned, alpine.  The  populations greatly  1982  In  greater  high  populations  slopes being 1981  the  essentially  snow-free  low  winter  appeared  than  by was  at  snow w i n t e r in  with  the a v a i l a b l e range  lamb p r o d u c t i o n  f o l l o w i n g an  snow-free winter  a high  severe  the  lamb/ewe r a t i o  lamb/ewe r a t i o was  following a  i n both  n e a r Toad R i v e r  s l o p e s but  restricting  Thus h i g h snow  19).  f o l l o w i n g an  subalpine  Churchill  subalpine  e a r l y March  was  in  the  the  both deep  snowfall  i n both  t o be  on  related  areas. to  winter  accumulation.  SURVIVAL RATES The  only d i r e c t  survival  w h i c h gave any  indication  of  r a t e s were:  1) A minimum o f summer of  data  1981  e i g h t a d u l t ewes o u t s u r v i v e d the  winter  of  and  10 c o l l a r e d were seen  in  in the  the  112  Table 19.  Lamb/ewe and yearling/ewe counts of Stone's sheep on F e r t i l i z e r Mountain and at the C h u r c h i l l mine (1980-1982)  Location and Date  Lambs/ewe  #lambs counted  Yearlings/ewe  #yearlings counted  F e r t i l i z e r mountain area: June, 1980  0.60  64 0.53  March, 1981 June, 1981 March, 1982 November, 1982  0.74  17  -  -  °-  17  5 0  0.35 0.38  March, 1983  20  C h u r c h i l l Mine: July,1980  0.49  64  0.28  23  J u l y 1981  0.18  22  0.27  32  June,  0.26  90  0.19  66  1982  .  113  summer o f  1982.  2) A l l of t h e  33  January,  survived until  1982  T h e s e two adult  animals  of  account  winter In  of  f o r a d u l t ewe  1981  and  the C h u r c h i l l  1981,  a severe  estimate  42%  low.  19)  the y e a r l i n g / e w e and  adding  mortality.  d u r i n g the  area,  On  more y e a r l i n g s t h a n  1982  lambs) due  f o r 1981.  estimates  The  of w i n t e r  was  ratios  for  additional  10%  22%  d u r i n g the  winter  of  mild  1982.  lamb m o r t a l i t y f o r  i n the a l p i n e , of  an  by  Fertilizer  severe  the e s t i m a t e d  f o r the winter  reasonable  in general, natural  lamb m o r t a l i t y was  winter  lamb/ewe r a t i o  with  (Table  Mountain, estimated  in  lamb w i n t e r m o r t a l i t y were made  lamb/ewe r a t i o s  f o l l o w i n g year  Mountain  1982.  that  m o r t a l i t y r a t e s were q u i t e  comparing  to  April,  points indicate  Crude e s t i m a t e s  the  using F e r t i l i z e r  was  55%.  The  unreasonable  (i.e.,  to a questionably average  f o r the  low  three  lamb m o r t a l i t y was  40%.  GROUP S I Z E The  average  g r o u p s i z e was  Most g r o u p s r a n g e d to  see  often  single  from  3-6  4.8  in size  s h e e p or p a i r s .  Large  c o n c e n t r a t e d around m i n e r a l  winter,  l a r g e groups  (20+)  ± 3.0 but  (S.D.) (n i t was  g r o u p s of  licks  not  unusual  sheep  i n summer.  sometimes o c c u r r e d  71).  (50+) In  in areas  1  where many sheep were r e s t r i c t e d t o a small area by snow  115  DISCUSSION  SEASONAL PATTERN OF  A MODEL OF  FOOD AND  Within  limited  gut.  This  t o meet  i t s energy  t o some l o w e r  Baumgardt  by p a s s a g e  consume  rate  intake  through the  i s observed i n domestic  1970), cows  s h e e p have a d a i l y  requirement  of about  1978)  which  i s almost  sheep  (NRC  1975).  digestible  energy  110  sheep  ( C o n r a d e t a l . 1964),  from  112  kcal/W°-  -  156  exceed  the maintenance  digestible kcal/W 0  (Table 20).  However, t h e e n e r g y trials  requirements  for bighorn individual  The  r e q u i r e m e n t s o f penned  Hebert  7 S  energy  i s about  daily  kcal/W° - .  requirement depending  i n domestic sheep  maintenance  128  7 5  r e q u i r e m e n t s o f an  state  Hudson  t o the v a l u e f o r domestic  r e q u i r e m e n t of  energy  maintenance  ( C h a p p e l and  7 s  This value corresponds to a  Actual  physiological  maintenance m e t a b o l i c  identical  (1973) r e p o r t e d d a i l y  grazing  a sheep w i l l  (Ammann e t a l . 1973).  Mountain  ranging  MOUNTAIN SHEEP  requirements unless  level  general pattern  ( D i n i u s and and d e e r  ENERGY INTAKE FOR  t h e model I assume t h a t  enough f o o d is  NUTRITION  will on  often the  energy c o s t  1.25 sheep  of  times the (Osuji  r e q u i r e m e n t s of mountain t e n d t o be c l o s e r  sheep.  1974).  sheep i n  to values for grazing  116  Table 20.  Digestible energy requirements of sheep under d i f f e r e n t p h y s i o l o g i c a l conditions.  Physiological State  Digestible Energy Reauirements kcal/lV  Multiple o f Maintenance  Minimum ^ Adequate DMD %  7 5  Maintenance  128*  1.0  48.0  Early  140*  1.1  49.0  Late gestation  232*  1.8  60.0  Lactation  319*  2.5  69.0  Lamb growth  339*  2.7  79.0  Adult weight gain of 0.02 g/day  140**  1.1  49.0  Adult weight loss of 0.02 g/day  115**  0.9  47.0  Maintenance + Thermoregulation below -20°C  178***  1.4  54.0  gestation  * NRC 1975 **Garrett et a l . 1959 ***Chappel and Hudson 1978 1 calculated from model  117  domestic sheep than to penned domestic sheep, p o s s i b l y to the s t r e s s a s s o c i a t e d with c a p t i v i t y of mountain compared to d o c i l e domestic sheep.  due  sheep  T h e r e f o r e , an energy  expenditure f o r g r a z i n g was not added t o the maintenance level. Gross energy content of most mountain sheep forages i s about 4.3 - 4.4  kcal/g  (Hebert 1973).  The d i g e s t i b l e  energy content of forage can be estimated by m u l t i p l y i n g the  gross energy value by the dry matter d i g e s t i b i l i t y  (DMD)  of the forage.  T h e r e f o r e , the food requirement of a  mountain sheep can be c a l c u l a t e d by the equation: Food requirement (g/day) = (a) (128) (4.4)  (W - ) 0  75  (DMD)  where: a = m u l t i p l e of maintenance requirement from Table 20, W  = body weight i n kg, and  DMD  = dry manner d i g e s t i b i l i t y expressed as a  proportion.  The maximum l e v e l of forage intake i n ruminants i s l i m i t e d by the passage r a t e through the gut (Blaxter et al.  1961, Conrad et a l . 1964).  animal i s r e l a t i v e l y constant the  only way  Because outflow from the ( P h i l l i p s o n and Ash 1965),  that food intake can i n c r e a s e i s i f more of  118  it  i s digested.  digestibility  Therefore,  i n t a k e i n c r e a s e s as forage  i n c r e a s e s u n t i l energy requirements a r e met.  Data on intake r a t e versus  forage d i g e s t i b i l i t y when  gut c a p a c i t y i s l'imiting a r e presented and  bighorn  sheep i n F i g u r e 29.  c a l c u l a t e d excluding  f o r domestic sheep  The l i n e a r r e g r e s s i o n was  the four low o u t l y i n g p o i n t s f o r  which i n t a k e appeared t o be w e l l below the gut c a p a c i t y . T h i s r e l a t i o n s h i p i s used i n the model t o c a l c u l a t e maximum intake c a p a c i t y . The  maximum p o s s i b l e energy intake w i l l be the product  of the maximum c a p a c i t y and the d i g e s t i b l e energy of the food.  Since DMD i n f l u e n c e s both of these  content values,  changes i n DMD have a m u l t i p l i c a t i v e e f f e c t on energy intake when the d i g e s t i v e system i s a t c a p a c i t y 30).  Therefore,  (Figure  small changes i n DMD can have q u i t e major  e f f e c t s on the energy intake of the animal. In the model I assume that the a c t u a l food the animal w i l l be whichever v a l u e , maximum c a p a c i t y , i s l e a s t .  i n t a k e of  food requirement or  That i s , the sheep w i l l  feed  to meet i t s energy requirements unless r e s t r i c t e d t o a lower consumption by gut c a p a c i t y .  The value  f o r food  requirements w i l l depend on body weight, p h y s i o l o g i c a l s t a t e of the animal, and the DMD of the food.  Maximum  c a p a c i t y i s a f u n c t i o n of body weight and the DMD of the food.  Figure 29.  Relationship between digestibility of the food and the daily intake of sheep when digestive capacity is limiting.  MAXIMUM ENERGY INTAKE  Lactation Rcquirtmtnt  model's prediction  121  IMPLICATIONS The energy  OF THE MODEL  v a l u e f o r DMD a t w h i c h t h e c a l c u l a t e d intake (capacity  requirements provide is  a function  energy  forage d i g e s t i b i l i t i e s  The  ewe a r e p r e s e n t e d  Table  19. about  energy  limit  intake  As e n e r g e t i c  also  of forage  increase (Figure 30).  requirements  i n F i g u r e 31 b a s e d  requirements  A t lower  f o r a 50 kg  on t h e d a t a i n  were c a l c u l a t e d  assuming  25% o f t h e d a y s a r e below - 2 0 ° C and r e q u i r e  maximum p o s s i b l e  digestibility Although  the season,  were u s e d  November  energy  measurements were  depend on t h e  fecal  protein  collected  values  a s a measure o f f o o d q u a l i t y  because  they  (corrected for from May t o  i n d i c a t e what t h e a n i m a l  t h a n what was a v a i l a b l e .  calculated  intake w i l l  o f t h e f o r a g e b e i n g consumed by t h e a n i m a l .  forage q u a l i t y  throughout  rather  The minimum  f o r thermoregulation.  The  ash)  will  p a t t e r n of energy  adult  that  level.  will  t h e minimum q u a l i t y  t o meet demands  Winter  will  30). Capacity  a n d f o r a g e DMD.  gut c a p a c i t y  increase,  annual  (Figure  that  i s e s t i m a t e d t o be 48%.  the food requirement  required  the energy  on w h i c h a 50 kg s h e e p c a n meet i t s  requirements  requirements  needs  o f body w e i g h t  forage d i g e s t i b i l i t y  below  equals  r e p r e s e n t s t h e minimum f o r a g e DMD  the animal's  maintenance  limit)  maximum  f r o m May t o November  The DMD from  consumed  o f t h e f o o d was  the f e c a l  protein  8000  7000 H  6000-1  ra ra o  sc  5000 H  O  oc UJ  z  4000  LU 111  _J  CD  3000  (0 UJ  O  2000  1000+  MONTH  Figure 31. Seasonal pattern of daily energy intake and energy requirements of a 50 kg ewe predicted by the model. T = Thermoregulation, G = Gestation, L - Lactation  123  data and  using the regression equation Reardon  (1963).  seem t o p r e d i c t quality  However, f e c a l  reasonable  was v e r y  presented  low.  ate a l l the forage,  values  protein  protein  d i d n o t d e c l i n e below an  o f 10% even t h o u g h f o r a g e p r o t e i n  (Figure  24).  decreased  digestibility  levels  protein  does n o t d i s t i n g u i s h  forages.  (Mould  probably  of p r o t e i n  protein  when  even when t h e s h e e p  average  This disparity  values d i d not  f o r food q u a l i t y  In the w i n t e r ,  fecal  by Lambourne  and R o b b i n s  was o n l y  results  at very 1981).  4%  from a  low c r u d e Therefore,  between p o o r a n d v e r y  T h i s p r o b l e m e x p l a i n s why f e c a l  protein  failed  to differentiate  severe  w i n t e r s and between a l p i n e and s u b a l p i n e  fecal  poor values  s h e e p c o n d i t i o n between m i l d a n d winter  range. B e c a u s e s h e e p consumed v i r t u a l l y a v a i l a b l e during a severe available eaten. for  forage  Given  supply and  as the forage  t h e DMD  o f t h e f o o d , t h e maximum using the values  ( F i g u r e 29) a n d d i g e s t i b l e  k c a l / g = 4.4 x DMD). i n winter  early  fall  of the  of the food  digestibility  months.  i n t a k e was c a l c u l a t e d capacity  the d i g e s t i b i l i t y  represents the d i g e s t i b i l i t y  T h i s v a l u e was u s e d  the winter  (i.e.  winter,  a l l the forage  energy  f o r maximum  energy  content  of food  Requirements exceeded the  b u t were l e s s  (Figure 31).  possible  than  the supply  i n summer  Over t h e s e a s o n , t h e  124  calculated  energy  b a l a n c e d by  the  deficit  summer-fall  daily  winter d e f i c i t  daily  weight  al.  1959),  loss  of  1200  (Stelfox  k c a l / d a y would r e s u l t  106  g/day  of a b o u t  12-13  i s comparable t o the  reported f o r bighorn 1976).  The  food  food ad  on  1978,  weight  declines  Nordan e t a l . 1968).  the metabolic programmed wild.  It i s unlikely  reduce  their  (1978) b u t  Voluntary  exceeding natural  ungulates  from  fall winter.  and  stasis Hudson  as  available  available  i n the  voluntarily  suggested  t h e y e a t a s much a s their  that  is genetically  ungulates  by  Mautz  t h e y can  given  digestive capacity.  reduction i n c a p t i v e animals  anomaly r e s u l t i n g  weight  winters  i n weight  (Chappel  t o the energy  imposed by  winter.  T h i s phenomenon s u g g e s t s  i n t a k e i n the w i l d  the l i m i t a t i o n s  the  with access to high  resulting  that wild  rather that  in a  a voluntary reduction in  i n deer  p a t t e r n of w i l d  to correspond  The  f a t f o r the next  deer  exhibit  i n t a k e d u r i n g the w i n t e r  i n . s h e e p and  kg o v e r  s u r p l u s i n summer and  to put  libitum  was  et  18-22% o v e r w i n t e r  C a p t i v e m o u n t a i n s h e e p and quality  (Garrett  sheep d u r i n g severe  energy  would a l l o w the a n i m a l s  (200,000 k c a l )  s u r p l u s (215,000 k c a l ) .  l o s s of a b o u t  for a total  This value  i n winter  i s possibly  food q u a l i t y  an  greatly  demands w h i c h a r e programmed t o c o r r e s p o n d  food  quality.  to  125  It  may  seem u n u s u a l  capability it  t h a t an a n i m a l  of u s i n g abnormally  i s available.  et  abundant  However, n o n - g r o w i n g  have a m a i n t e n a n c e m e t a b o l i c animals  hormone  levels  maintaining energy deficit energy Elk  decreases  under  ability  the usual winter  weight  the w i l d  increases,  food  that they  i n w i n t e r , presumably  requirements. on l o w e r  surplus  a greater  Larger  quality  p r e d i c t s a minimum  energy  requirements  i n winter (Hudson  a r e n o t programmed because w i n t e r  forage  maintenance  ruminants  c a n meet  their  f o r a g e b e c a u s e a s body  the metabolic  tract  rate.  forage d i g e s t i b i l i t y  maintenance requirements  loss  in captivity  the c a p a c i t y of the d i g e s t i v e  a g r e a t e r r a t e than  they  to u t i l i z e  a weight  i s a d e q u a t e t o meet t h e i r  requirements  the  Therefore,  c o n d i t i o n s of a negative  and moose do n o t e x h i b i t  metabolic  at  (Silver  balance.  p e r s . comm.) w h i c h s u g g e s t s  in  t o grow  would e n t a i l  when p r o v i d e d w i t h h i g h q u a l i t y  to lose  i n winter  i n t h y r o x i n e and g r o w t h  the p h y s i o l o g i c a l i n winter  when  T h i s decrease i s  (Bahnak e t a l . 1981).  f o r growth  ungulates  geared  a l . 1969, H o l t e r e t a l . 1977). to winter  food energy  r a t e below t h e l e v e l o f  which a r e p h y s i o l o g i c a l l y  related  d o e s n o t have t h e  size  increases  The model  o f 42% t o meet t h e  o f a 200 kg e l k a n d 39% t o meet  o f a 400 kg moose.  can o b t a i n food of t h i s q u a l i t y  It is likely i n winter.  that  126  and  Another aspect  to t h i s  forage q u a l i t y  requirements  growing  t o an  1980).  The  adequate  size  model p r e d i c t s  m a i n t e n a n c e needs on digestibility  50%  f o r a 20  below t h e m a i n t e n a n c e w e i g h t more q u i c k l y rams w i l l than  r e l a t i o n s h i p between body  be  i s the  that a  30  lamb  kg  lamb c a n  larger  a b l e t o s u r v i v e on  lambs  (Bunnell meet  f o r a g e compared t o  ( F i g u r e 32).  requirement,  than  of  to s u r v i v e the w i n t e r  digestible  kg  importance  size  When DMD  s m a l l lambs w i l l  lambs.  52%  Similarly,  less digestible  is lose  large,  forage  ewes.  PROTEIN NUTRITION The  seasonal crude  compared  to the crude  f o r a g e and fecal  protein protein  the p r o t e i n  protein  values  f o r a g e was  less  spring  forage crude  but  requirements was  The  previously.  21.  protein  f o r sheep  available  protein  food p r o t e i n  food p r o t e i n  from  P r o t e i n supply during winter  content  are  i n the  food p r e d i c t e d  in  and  early  exceeded  summer months when new  fecal  d e p e n d a b l e measure of overestimated  of  requirements  d u r i n g the  available.  content  content  in Table  than  requirements  production  v a l u e s were p r o b a b l y i n the  in winter  summer but  for reasons  a  they,  discussed  MINIMUM D M D PROVIDE l-i  o  CD OJ  ts) l-h O H. p TO fD  PO CD I— p r+ HO CL 3 H - </) TO 3 * fD H C/l " 3  cr  1  to O  fD  H ' fD r+ fD  00  O a •<  5" —  cr 2- o CL  ct £ fD fD MrrTO  w o  m  o z  o sr fD O fD i - h rt  o  t/i 3 =rP5 CD H * CD  Ul .  7?  n- „ CD 3  o  ca  P 3  3  n  fD  o o  CD  2C 3aH-  MAINTENANCE  CD  l-i  I 3* rt  o  t/l CD  • a. n  os. o  r+  o 3  o Hi  3 3 H3  LIX  (%)  TO  REQUIREMENTS  128  Table 21. Protein a v a i l a b i l i t y i n forage on Stone's sheep ranges compared to protein requirements o f domestic sheep.  Requirements for Crude Protein i n Diet*  Crude Protein i n Available Forage  Protein Content of Food Intake**  a.  Winter: E a r l y gestation  9.0  4.0  Ram maintenance  8.9  4.0  9.3  18.0  8.7 - 20.0  Lactation  10.4  18.0 - 25.0  21.0  Lamb growth  16.0  18.0 - 25.0  21.0  Spring: Late gestation Summer:  * NRC 1975 ** estimated from f e c a l protein using the equation from Hebert (1973): Crude Protein i n Diet= -0.94 + 1.034 x Fecal Protein  129  SUMMARY OF SEASONAL NUTRITION PATTERNS Stone's sheep i n winter were f o r c e d t o eat forage which was too low i n d i g e s t i b i l i t y t o meet energy requirements essential  and was d e f i c i e n t  mineral elements.  i n p r o t e i n and many  The animals  were f o r c e d to  r e l y on s t o r e d reserves f o r winter s u r v i v a l .  The onset of  new p r o d u c t i o n i n the s p r i n g p r o v i d e d high q u a l i t y which exceeded the immediate requirements throughout  forage  of the animals  the summer and allowed them to accumulate  r e s e r v e s f o r the next winter.  The seasonal  nutritional  regime was m i r r o r e d by f e c a l p r o t e i n and DAPA v a l u e s .  1 30  S E L E C T I V E FEEDING  RANGE SELECTION In w i n t e r , when S t o n e ' s nutritional  problems,  restrictions ranges This  with  d o m i n a t e d any  range and  ranges  food.  in winter  i n deep snow.  use  Cowan  The  and  ranges  i n w i n t e r was  rather  than  less  possible  than  severe  25-30  selection  both a l p i n e  so l o n g a s  t h e y were  of  snow i n  but  and  not  (1971),  Hoefs  Selection  for available  f o r a r e a s w i t h abundant  cm.  restricting  r e p o r t e d by G e i s t  selection  to  for areas  Sheep u s e d  Simmons e t a l . ( 1 9 8 1 ) . thus  severe  Sheep were r e s t r i c t e d  of  role  of s h e e p i s a l s o (1979),  f a c e d t h e most  range.  snow a c c u m u l a t i o n s  w i t h more o r b e t t e r  covered  they a l s o  of a v a i l a b l e  restraint  subalpine  s h e e p f a c e d t h e most  of  food  snow-covered  forage. Avoidance reduce  of a r e a s  energy  expenditures  are p a r t i c u l a r l y given and  their  Kelsall  low  c h e s t h e i g h t and  would a c t Mountain  f o r movement t h r o u g h high  Also, i f their  foot-loading  food  i s covered  to  sheep snow  (Telfer by  deep  spend a l a r g e amount o f t i m e d i g g i n g t o  reach  i t (Figure 25).  major  factor  The  which l i m i t e d  sheep.  for locomotion.  p o o r l y adapted  1971).  snow t h e y must  Stone's  w i t h h i g h snow d e p t h s  Abundant  influence  o f snow d e p t h  the v a l u e of range  f o r a g e on  the burned  was  the  burning for slopes  was  131  usually the  u n a v a i l a b l e t o the animals  sheep with  nutritious  was a v a i l a b l e gradual early  on a l p i n e r a n g e s  July continued  slopes.  declining  on a l l r a n g e s ,  used a g r e a t  e l e v a t i o n s throughout  forage  In f a l l ,  sheep w i t h  variety  were s t u d i e d i n d e t a i l altitudinal  migration  o f abundant  high quality  than  forage  when f o r a g e q u a l i t y  o f range t y p e s . migration  by H e b e r t  on t h e  was  selective  The n u t r i t i o n a l  o f mountain  (1973).  sheep  During the  t h e s h e e p a r e u s u a l l y moving  low q u a l i t y  food t o areas  from  of sparse but  food.  of m i n e r a l  studies  (Simmons  mineral  licks  licks  1982).  i n summer had i m p o r t a n t  licks  Although  i n summer, t h e y  sodium as i n o t h e r  effects  and o t h e r  Sheep a r e u s u a l l y found  i n summer.  for foraging.  (Fraser  J u n e and  was a v a i l a b l e  t h e range use p a t t e r n s o f t h e sheep i n t h i s  range  The  the best  s h e e p were t h e l e a s t  b e n e f i t s of the a l t i t u d i n a l  subalpine  than i t  In summer, t h e a l p i n e r a n g e u s e d by s h e e p  subalpine  Use  far earlier  ( F i g u r e s 8 and 9 ) .  to provide  p r o v i d e d more n u t r i t i o u s  areas  i n spring provided the  new p r o d u c t i o n  movement t o h i g h e r  available.  on  time of  year. Movement t o s u b a l p i n e a r e a s  and  at the c r i t i c a l  close to  some s h e e p u s e d  returned  to the a l p i n e  Sheep a p p e a r e d t o u s e l i c k s s t u d i e s of ungulate  e t a l . 1980).  Most  mineral  to obtain  licking  f o r a g e s do n o t c o n t a i n  132  a d e q u a t e amounts of sodium t o meet al.  1979) a n d l i c k i n g  need.  behaviour appeared  Requirements f o r other  s u p p l i e d by summer f o r a g e elements than Overall,  body needs  the mineral the seasonal  to s a t i s f y  this  e s s e n t i a l elements c o u l d  w h i c h were h i g h e r  be  i n these  licks. pattern  o f movements  sheep r e s u l t e d i n the a n i m a l s  feeding  most n u t r i t i o u s a v a i l a b l e f o o d  while  s o d i u m demands  (Maynard e t  by S t o n e ' s  i n areas  with  the  also satisfying  their  i n summer.  SELECTION OF FORAGE SPECIES Stone's sheep avoided  eating several plant  w h i c h c o n s t i t u t e d a l a r g e amount forage not  biomass.  less  P l a n t s w h i c h were a v o i d e d  n u t r i t i o u s than o t h e r  Arctostaphylus,  Table  Betula  and  characteristics  leathery c u t i c l e s  D r y a s , and c o n i f e r s , and s t i c k y  higher  on  secretions  over grasses  i n summer.  graminoids  p r o t e i n ) on s p r i n g and summer  sheep d i d not appear  preferentially forbs  were  qlandulosa.  fibre,  However,  apparently  (see B e t u l a  F o r b s were u s u a l l y more n u t r i t i o u s t h a n (lower  available .  T h e s e mechanisms were n o t  b u t i n c l u d e d waxy a n d / o r  Arctostaphylos, on  foods  5) b u t r a t h e r had  w h i c h made them u n p a l a t a b l e . quantified  of the t o t a l  species  This  to select  forbs  i n s p r i n g and s e l e c t e d  i s contrary  ranges.  to the optimal  against foraging  133  h y p o t h e s i s but  may  be  due  to  compounds i n f o r b s compared less  palatable.  which are  D e l p h i n i u m , and can  when a  large  tend  to  be  be  be  toxic  Zigadenus  consumed amount  lower  i s eaten.  i n new  i n summer may  1974).  of  collected  at  selecting  better  toxic  the  have been due  the  of  of  are  these toxic  compounds ones  selection  to  high  levels  forbs.  (estimated  quality  random s u g g e s t e d  protein.  of  that  The  lack be  of  a  r a n g e may  t h e r e was  no  need t o  s h e e p may  have been u n a b l e t o  be  in quality  quite highly  at  that  from  fecal  forage which the  than average q u a l i t y  f o r a g e on  differences  but  ranges  Aconitum,  Most  i n mature  Therefore,  food q u a l i t y  values) with  t e r m s of  the  SUPERIOR QUALITY FORAGE  Comparison protein  1980).  than  compounds i n many s p e c i e s  SELECTION OF  secondary  Lupinus,  L e v e l s of  plants  against toxic  including  in small q u a n t i t i e s  Janzen  of  of  g r a m i n o i d s w h i c h make them  (Stephens  ( F r e e l a n d and forbs  to  levels  T h e r e were numerous f o r b s on  known t o  plants  higher  s h e e p were food, at  a difference  was not  least  suggests  homogeneous i n q u a l i t y selective. distinguish level.  in that and  Alternatively, between  134  SELECTING A MIXED DIET According could  have  obtained for  f e d on  a very  other  only willow  nutritious at  times  diet.  biological i)  of t h e  Westoby  iii)  year,  The  summer  and  same c o u l d be  other  times  said  of the  particular  they  year.  food  types  always maintained  search costs w i l l  taking  s e v e r a l foods  I f the  optimal  will  a  the  food type  optimal foods  these  reasons  SEXUAL DIFFERENCES IN Differences expected  are  changes with of these  the  best  the  foods. of  source  apply  will  foods  t<  of negative  be  mixed.  to Stone's  sheep.  SELECTIVITY  i n body s i z e and  e n e r g e t i c demands m i g h t  t o cause d i f f e r e n c e s i n forage  between rams and  time,  food.  optimum d i e t may  from  value.  n u t r i e n t s ( o r n o n - s o u r c e s of  compounds) t h e of  result  have t o sample a v a r i e t y  If d i f f e r e n t different  of equal  contain a mixture  A n i m a l s may  iv)  can  i n the  sheep  (1978: 627-628) d i s c u s s e d  determine the  ram  and  Stone's  b a s e s of v a r i e d d i e t s :  diet  be  shrubs  diet.  this  A r e d u c t i o n of  ii)  All  data,  s h e e p d i d f e e d h e a v i l y on  certain  varied  food q u a l i t y  food types  Although at  t o the  ewes.  meet m a i n t e n a n c e  The  selectivity  model p r e d i c t s t h a t a 70  requirements  on  46%  kg  digestible  135  f o r a g e compared t o 48% (1977) s u g g e s t e d in  bighorn  that  f o r 50  differential  sheep m a y b e  related  strategy.  However, Shank  population  and  spatial  sexes  concluded  separation arose  preferences. onto  distinct  of  ewe  the  groups  but  separation  that  i t was  d i d not  range.  ewes was  in  foraging  that  this  diet  occur.  s e p a r a t i o n of Over s h o r t  spatially  separate  r e g u l a r l y made  Therefore, n o t due  sexes  t h e same  spatial  they  Petocz  between  unlikely  were o f t e n  i n a l l seasons  o f rams and  and  to d i f f e r e n c e s  from d i f f e r e n t i a l  groups  same a r e a s o f t h e  use  (1982) s t u d i e d  ranges  ram  Geist  range  In t h e p r e s e n t s t u d y ,  p e r i o d s of time, from  kg ewes.  to  use  spatial differential  range p r e f e r e n c e s . Alternatively, lower  quality  requirements  expected  However, poorer  predict  ewes b e c a u s e  with less d i g e s t i b l e  The  because  w i n t e r and  might  f o o d than  f o u n d no d i f f e r e n c e in winter.  one  between  sexes  selective.  requirements In f a c t ,  Shank  their  (1979)  o f rams and  might  have  ewes  been  were below m a i n t e n a n c e i n  i n summer, rams might  meet t h e i r  t h e y can meet  food q u a l i t y  s h o u l d have s e l e c t e d  f o r a g e , i f i t was  rams w o u l d e a t  forage.  l a c k of a d i f f e r e n c e both  that  the best be  food  expected  to  available. select  v e r y a b u n d a n t a l l o w i n g them t o in less  t h e r e was  h a b i t s or the food q u a l i t y  time  than  by b e i n g  no d i f f e r e n c e  a s m e a s u r e d by  i n the  fecal  highly food  protein  136  and DAPA l e v e l s between rams and ewes i n summer. T h e r e f o r e , there was no reason t o b e l i e v e that sexual d i f f e r e n c e s i n food s e l e c t i v i t y The  exist  i n Stone's sheep.  l a c k of a d i f f e r e n c e i s f u r t h e r evidence  that sheep do  not have t o be h i g h l y s e l e c t i v e when feeding i n summer. There was no lack of h i g h q u a l i t y had  food once the animals  s e l e c t e d the best range.  SUMMARY OF FOOD SELECTIVITY Stone's sheep s e l e c t e d the range which c o n t a i n e d the most n u t r i t i o u s a v a i l a b l e f o r a g e .  C e r t a i n foods were  avoided, probably because of p l a n t c h a r a c t e r i s t i c s which made them u n p a l a t a b l e . selectivity,  Beyond these i n i t i a l  sheep d i d not seem t o s e l e c t  l e v e l s of  forage which was  any more n u t r i t i o u s than the average food a v a i l a b l e . Apparently  once the sheep had s e l e c t e d the best range and  avoided u n p a l a t a b l e foods, there was no need or o p p o r t u n i t y t o feed more s e l e c t i v e l y .  137  INTAKE RATE Both b i t i n g available  r a t e and  forage  evident  i n the  between  s h e e p on  clearings. areas,  to a greater consistent  length  1970).  but  1970,  intake.  This  grazing reindeer intake  increases 1981).  tiller  as  not  s i m i l a r on  forage The  by  on  foraging  biomass  increases  possible to  r e l a t i o n s h i p between t i l l e r Stone's sheep because the  biting  daily  length  and  altitudinal  for from and  which  ( T r u d e l l and  investigate  White  the  biting  by  tiller  differs  rate  for  periods  reported  but  sheep  Whittaker  remains q u i t e constant the  tiller  of domestic  i s s i m i l a r to that 1976)  the  and  r e s u l t i n g in a decreased  Stobbs  biting  compensated  longer  due  r e s u l t s are  ( A l l d e n and  is partially  both  biomass  (Allden  Bite size  lengths  i s d e t e r m i n e d by  I t was  natural  i s i n c o m p l e t e when g r a s s  (Chacon and  forage  was  spring  sheep i n which  density  1975).  i n which b i t e s i z e  rate  to  tillers.  of  particularly  p r i m a r i l y dependent  r a t e and  pattern  cows  grass  bite size  short  was  a much h i g h e r  tiller  compensation  i s very  length  for domestic  Arnold  biting  point  d i f f e r e n c e i n the  grass  rate are  short  increased  length  data  t i m e were i n d e p e n d e n t  r a n g e compared  of  than the  Smaller  this  burned  density  rather  This  of any  r a n g e s had  with  d e c l i n e s at  an  lack  intake  Whittaker  biomass.  A l t h o u g h the  burned  r a t e and  foraging  rate  migration  of  of the  138  sheep r e s u l t e d tiller  length  i n them a l w a y s was a b o u t  feeding  8 - 12 cm ( F i g u r e 8 ) .  When t h e s h e e p were on s p r i n g predicted on  a maximum d a i l y  65% d i g e s t i b l e f o r a g e  this  value  i n a r e a s where t h e  food  r a n g e , t h e model  capacity  t o be a b o u t  o f a ewe  1837 grams.  by t h e number o f b i t e s / d a y b i t e s i z e o f 0.08 grams.  This  identical  to the value  sheep f e e d i n g  10  cm l o n g  close  ( A l l d e n and W h i t t a k e r  (Figure  10) s u g g e s t i n g  i n d i v i d u a l small  rate  i s about  domestic  Whittaker  were a b l e  1970).  1970, A r n o l d  on 8,-  It i s also  plant  of t h a t  most b i t e s c o n s i s t o f The e s t i m a t e d  i f t h e y were c o n s u m i n g  intake their  I t i s i n t e r e s t i n g t o note maximum r a t e  1975).  that  o f i n t a k e on  These o b s e r v a t i o n s  t h e zone o f 10 cm g r a s s  t o maximize  Such b e h a v i o u r  intake  hypothesis  rate while  q u a l i t y of grass  i s consistent  rate  (Schoener  intake  r a t e o f t h e s h e e p was o n l y f o r domestic  1971).  sheep  Stone's  suggest sheep  simultaneously available  (Figure  with the optimal  i . e . , maximization  intake  reported  i s almost  w i t h a b i t e s i z e o f 0.08 g ( A l l d e n a n d  on t h e h i g h e s t  foraging  tiller.  of food.  by f o l l o w i n g  19).  that  sheep c a n a t t a i n t h e i r  8 - 10 cm g r a s s  feeding  grass  2.7 g/minute  maximum c a p a c i t y  that  value  t o t h e w e i g h t o f an i n d i v i d u a l g r a s s  length an  grass  Dividing  (23000) g i v e s an  estimated  f o r domestic  feeding  of net energy  However, t h e c a l c u l a t e d a b o u t h a l f t h e maximum  ( A l l d e n and W h i t t a k e r  1970).  139  The  d i f f e r e n c e r e s u l t e d from Stone's sheep b i t i n g  about  half  feeding  the rate  f o r almost  (33 compared t o 60 b i t e s / m i n u t e ) . twice as long  Stone's sheep took about the  domestic  This may  by A l l d e n  d i f f e r e n c e between d o m e s t i c Stone's  planted  pasture.  reducing  their  biting  not  forage  (1977) f o u n d t h a t  pasture  both  foraged  lactating that their  daily  g/minute).  important  Therefore,  they can.  foraging.  slightly  over  sheep  level  when  latter  domestic  s h e e p do  r a t e but r a t h e r  A r n o l d and  o f time but t h a t that  time  (1975) f o u n d longer  factor allowing  was a g r e a t e r  maximum r a t e p o s s i b l e  needs.  intake  S i m i l a r l y Arnold  intake  that  f o r t h e same l e n g t h  sheep foraged  t h e most  s h e e p on  f a t s h e e p and t h i n s h e e p on good  t h i n sheep had a h i g h e r  1.8 g / m i n u t e ) .  The  a t t h e maximum p o s s i b l e  Birreli  if  quickly.  t h e r a t e d e p e n d i n g on t h e i r  the  sheep  r a n g e were  r a t e as domestic  i s s u p p o r t e d by t h e f a c t  usually  vary  s h e e p and S t o n e ' s  r a t e t o a more r e l a x e d t o feed  as  (1970).  A l t e r n a t i v e l y i t may r e s u l t from  they a r e not pressed hypothesis  and W h i t t a k e r  s h e e p on n a t u r a l  u n a b l e t o a t t a i n t h e same b i t i n g  By  (700 v s 400 m i n u t e s )  t h e same number o f b i t e s / d a y  sheep s t u d i e d  i n d i c a t e that  at only  intake  (2.2 v s  that  than d r y sheep but them t o i n c r e a s e rate  s h e e p do n o t u s u a l l y  (2.17 v s 1.82 feed  at the  b u t slow down t o a more r e l a x e d  rate  Thus s h e e p a r e n o t " t i m e m i n i m i z e r s " when  A c t u a l l y there  i s no r e a s o n t o e x p e c t  sheep t o  140  eat  at  a  frantic  resting.  The  foraging by  may  The  a  rather  rate  animals which capacity.  Foraging  i n the  daylight  (Arnold  Overall, similarity  feeding  Foraging intake  and  foraging  The  most  m a i n t a i n an low  of  the  of  intake the  low rate  same  22). the  daylight good  u n a b l e t o meet proportion  Whittaker  behavior  adequate  or  (i.e.,  sheep under  important  the  sheep i s  daylight  a great  in plant  time  requirements  (Table  sheep which are  a p p e a r s t o be  very  the  f o r about  for domestic  1960b; A l l d e n  sheep.  ranges which are  was  food  amount of  f o r a much g r e a t e r  there  sheep can  this  w h i c h c o v e r s 60-70% o f  between t h e  domestic  Stone's  but  may  S t o n e ' s s h e e p under  intake  d a y l i g h t hours  forage  of  i n summer), a c o n s t a n t  standard  range c o n d i t i o n s needs w i l l  the  saved  maximization".  daily  seasonal  animals  activity  i s quite  of  i s d e t e r m i n e d by  high  the  foraging  rate  the  rapid  rate  f o r them t o m a i n t a i n .  in turn  of  for t h i s  than energy  "energy  of  for  greater  suggests that  function  in winter,  proportion  or  biting  Because the  would r e s u l t  and  of  c o r r e l a t e d with  intake  hours  great  constant  conditions  becomes a  roughly  as  strategy  "comfortable" then  be  more t i m e  required  Thus a c o n s e r v a t i v e  be  different  to provide  energy e x p e n d i t u r e well  resting.  actually  rate only  of  1970).  deal of  their  of  Stone's  point intake  sheep  i s that rate  biomass because  on intake  141  Table 22. Estimated foraging time of a Stone's sheep ewe seasons assuming a constant intake rate.  February  i n different  May  DMD  0.4  0.7  Estimated intake (g)*  900  2025  Foraging time  360  810  600  1320  0.6  0.6  Daylength  (minutes)**  (minutes)  Proportion of daylight foraging  * calculated from model **  assuming constant intake rate of 2.5 g/minute.  142  rate  is influenced  which  i s poor  resulted  f o r s h e e p i s one  in very  r a n g e s may  long  reason,  natural  same i n t a k e  spent  rate  by  intake  rate  rate  spring  when t h e  likely  size  they  1406  forage  a high  ranges  was  new  intake  appeared  in  food  that  larger  to  foraging  In  a  the  to a  greater Allden a  greater  the by  l a r g e mouth would the  i n the (1106  rams may  food g/day f o r The  explain  ewe  ram  difference  any  in foraging and  not  spring  Even without  Ram  a  food  gestation).  groups.  to  largely limited  t o ewes  i n separate groups.  the  time  due  s h e e p had  Therefore,  t i m e between ewes and  separate  be  However, i n  a v o i d a n c e between s e x e s , d i f f e r e n c e s lead  to allow  of d a y l i g h t  would be  late  this  spring.  abundant.  rams compared  is  For  requirement.  a difference  for  grass  l a r g e r mouth s i z e .  green p l a n t s  reflect  sheep  rate.  i s p r o b a b l y due  rate  range has  the  t o ewes c o u l d  lower  advantage.  g/day  but  rams have a g r e a t e r  intake  r e q u i r e m e n t s of  foraging  a  A  Mountain  grass cover  difference  p r o v i d e an  growth vs  or  large  of  5 cm).  lower p r o p o r t i o n  when f o o d  d i f f e r e n c e may  in  burned  length.  which g r a z i n g  clearings  (1970) f o u n d  rate  small  (<  r e s u l t i n g from a  intake  grass on  rams compared  the  Whittaker  the  as  consistently  requirement,  and  sparse  subalpine  w i n t e r when t h e  intake  grass  enough t o a l l o w  feeding  greater  short  have v e r y  usually  The  p r i m a r i l y by  why active  time  groups  will  143  often  foraged  or  rested together.  became s p a t i a l l y while  separated  because they  f o r a g i n g , l e a v i n g the  resting  A l a r g e biomass of dead negative burned  effect  on  f o r a g i n g on  dead g r a s s , presumably because to n u t r i t i o u s  similar  to the  f o r a g e on after  cattle  situation  antelope  with  new  growth  Food s u p p l y s p r i n g and  was  to  bulk  not  a problem  of the  sheep  s n o w f a l l t o meet t h e  capacity limitations  F o r most of  bf  the year  b i o m a s s of  food.  low  the  exposed  forage by  f o r mule d e e r  the  The  quality  by  a l l ranges  (Table  23).  no  requirements  (Table 23). food to  By  in or  but  even  late  eat.  s h e e p a p p e a r e d t o have  no  r a t h e r endeavour to o b t a i n  altitudinal food  on  c o n t a i n enough f o o d  sheep  essentially  p r o b l e m g e t t i n g enough f o o d high quality  of  production  winters  s h e e p had  antelope  f o r Stone's sheep i n  ranges d i d not  winter,  their  T h i s phenomenon i s  range  However, w i n t e r  the  with  (Wilms e t a l . 1979).  requirements  of h i g h  on  l a r g e amounts o f  Moderate g r a z i n g  improve  summer when f o r a g e  exceeded the  Sheep  s m a l l p l a n t s which are  ( V e s e y - F i t z g e r a l d 1960).  exposing  t o have a  i n which s m a l l A f r i c a n  remove t h e  i s a l s o thought  behind.  i t interfered  production.  highly nutritious  larger  biomass  new  rams  s p r i n g ranges.  areas  ewes s o o n  w o u l d move away  forage appeared  s p r i n g range a v o i d e d  access  However, t h e  to areas  movements from a of s p a r s e ,  high  high-  Table 23. Forage a v a i l a b i l i t y of several Stone's sheet) ranges compared to estimated sheep requirments.  Winter Range Type and Location  Available Forage  Number of Sheep  kg/100 days  kg Alpine (ridge above Churchill m i l l )  Winter Forage Requirements*  2000  15  13,000  8000  30  27,000  80,000  30  27,000  Subalpine, Burned ( F e r t i l i z e r mountain) high snow winter (1982) low snow winter (1981)  Spring Range Type and Location  Graminoid Production  Number of Sheeo  Natural Subalpine Clearings (slope shown i n Figure 5)  1  kg/day  kg/day Subalpine, Burned ( F e r t i l i z e r mountain)  Forage Requirements'  900  25  45  90  10  18  * Requirements calculated from model, winter requirements calculated f o r 100 days assuming intake limited by capacity.  quality food served t h i s objective.  146  ANIMAL CONDITION AND Poor w i n t e r with high (Stelfox  nutrition  to  of m o u n t a i n  lungworm l e v e l s w h i c h c a n 1976).  The  sheep, p a r t i c u l a r l y fairly  high  increased  poor winter  observed (W.  lead  may  larvae/g) t o be  in bighorns.  coughing  as  Samuel p e r s . comm.).  probably  not  of  reflected by  in heavily affected t o lungworm  i n lungworm  burned subalpine winter  range  superior  on  fact  l e v e l s may the  fecal  may  also  be  subalpine burns.  a better indicator  protein reduce  to  of a n i m a l  lungworm l e v e l s  body w e i g h t s  examine s e a s o n a l and  summary o f t h e s e d a t a  and  by  killing  host  t o the  was Stone's levels suggests lungworm  c o n d i t i o n than  o r DAPA l e v e l s d u r i n g w i n t e r .  range which a r e the a l t e r n a t i v e D a t a on  In  never  populations  between a l p i n e and nutrition  these  die-offs  A l s o , s h e e p were  the d i f f e r e n c e  sheep  led to  However,  l e a d i n g to  D e a t h due  in  snow of  a major cause of m o r t a l i t y i n these  s h e e p p o p u l a t i o n s but  die-offs  Stone's  a l s o have  t r a n s m i s s i o n of the p a r a s i t e s . those  t o major  nutrition  Restriction  d u r i n g the winter  l e v e l s were not as h i g h a s 1,400  sheep i s c o r r e l a t e d  o f a l p i n e s h e e p , was  lungworm l e v e l s .  small areas  (>  GROWTH  Burning  s n a i l s on parasite.  measurements were  inadequate  inter-population differences.  i s presented  the  i n Appendix I I .  A  147  Horn growth data showed that y e a r l i n g rams had s u p e r i o r horn growth on burned range. i s p r i m a r i l y dependent  Horn growth of rams  on s p r i n g n u t r i t i o n (Bunnell  1978).  Because other i n d i c a t o r s of s p r i n g range q u a l i t y showed no major d i f f e r e n c e between burned and unburned poorer horn growth of y e a r l i n g rams may the  range, the  have been due to  sheep from a l p i n e winter range coming onto the s p r i n g  range i n much poorer, c o n d i t i o n .  Yearlings  from the a l p i n e  winter range appeared to be s m a l l e r than y e a r l i n g s from s u b a l p i n e winter range.  The horn growth of o l d e r rams d i d  not d i f f e r between ranges and the i n i t i a l d i s p a r i t y due to b e t t e r y e a r l i n g growth had been l o s t by the time the animals were shot by h u n t e r s .  Although the horns from  burned range were no longer, they may  have been  better  t r o p h i e s s i n c e they tended t o have more t i p broomed o f f . T h e r e f o r e , range burning may  have a s l i g h t b e n e f i c i a l  e f f e c t on the p r o d u c t i o n of trophy rams.  148  POPULATION DYNAMICS Adult  survival  on t h e s m a l l of  sample  of c o l l a r e d  80%) a n d t h e 100% s u r v i v a l  winter  o f 1982 on F e r t i l i z e r  rates et  r a t e s a p p e a r e d t o be q u i t e  f o r a d u l t mountain  Typically,  annual losses  a n i m a l s (minimum  based  survival  o f ewes t h r o u g h o u t t h e Mountain.  sheep  a l . 1981, H o e f s a n d Cowan  high  Low m o r t a l i t y  (< 15%) a r e common  1979, G e i s t  to predation  (Simmons  1971).  and o t h e r  mortality  causes a r e very  low (< 10%) f o r p r i m e aged s h e e p b u t  mortality  increase  rates  f o r old-aged adults  (> 8 y e a r s  old). Low likely that  lambtewe c o u n t s were t h e most o b v i o u s f a c t o r to affect  population  lamb p r o d u c t i o n  poor n u t r i t i o n nutrition  growth.  i s often quite  I t i s not s u r p r i s i n g low c o n s i d e r i n g t h e  o f t h e p r e g n a n t ewes d u r i n g w i n t e r .  during  gestation  results  i n the b i r t h of  undersized  lambs  which e x p e r i e n c e a h i g h m o r t a l i t y  even u n d e r  ideal  conditions  following  birth  Lambourne  1958).  A similar  situation  occurs  elk  ( T h o r n e e t a l . 1976; Verme  reported  Poor  1977).  rate  (McClymont a n d  Heimer  i n deer and (1983)  lower f e t u s weights a s s o c i a t e d w i t h a reduced  lamb:ewe r a t i o  in Dall's  sheep.  w h i c h a r e most c o m p a r a b l e by McClymont a n d Lambourne poor n u t r i t i o n  The e x p e r i m e n t a l  t o mountain (1958).  during gestation  data  sheep a r e p r e s e n t e d  Sheep were p l a c e d on  until  4 weeks p r e - p a r t u m  149  and of  then given high q u a l i t y their  body w e i g h t  26% p e r i - n a t a l body w e i g h t  produced  mortality  lost  f e e d . . Ewes t h a t lambs w h i c h  daily  digestible  kcal/W°  7  conditions,  Prior  120 k c a l / W °  pregnancy  suffered  7  5  digestible  10% p e r i - n a t a l  t o o n l y 2% lamb l o s s digestible  Under b e t t e r  7  energy.  on  a n d 56.0  5  found t h a t  energy  relationship  ewes  throughout  lamb m o r t a l i t y  f o r ewes r e c e i v i n g This  Based  nutritional  and C h r i s t e n s o n (1976),  receiving  25%  loss correspond to  i n t a k e s o f 63.8 k c a l / W °  respectively.  5  had l o s t  lambs a t b i r t h .  the model, these v a l u e s f o r weight  22%  experienced a  whereas ewes w h i c h  41% o f t h e i r  had l o s t  compared  200 k c a l / W °  7  5  i s shown i n F i g u r e  33. In t h e w i l d , usually  o f 18% w o u l d  l o s s e s b e f o r e most  lambiewe c o u n t s a r e made ( H o e f s and Cowan  A l s o , many  studies,  including  ewes i n t h e c o u n t .  most  lamb m o r t a l i t y  be added t o t h e s e p e r i - n a t a l  reported  old  an a v e r a g e  sheep  this  Yearling  one, i n c l u d e d  1979).  2-year-  f e m a l e s do n o t b r e e d i n  p o p u l a t i o n s ( H o e f s a n d Cowan  1979).  I d i d not  observe  any 2 - y e a r - o l d ewes w i t h lambs i n t h e p r e s e n t  study.  Lamb/ewe  old 15%.  ewes w i l l These  c o u n t s which  underestimate  d a t a were u s e d  do n o t d i s t i n g u i s h  the lamb/adult  lamb:ewe r a t i o s  ewe by a b o u t  to generate a hypothetical  r e l a t i o n s h i p between w i n t e r n u t r i t i o n subsequent  2-year-  o f t h e ewes a n d  i n t h e summer  (Figure 33).  3  -J  50-1  <  DAILY D I G E S T I B L E E N E R G Y I N T A K E  OF E W E S  IN  WINTER  (kcal/W ) 7 5  £ o  Figure 33. Relationship between daily energy intake of ewes i n winter and the predicted values for peri-natal mortality and summer lamb/ewe ratio (2-year-old and older ewes).  151  These p r e d i c t e d v a l u e s  cover  lambrewe r a t i o s  and  (Hoefs  the normal  Cowan  1979).  (45-50 lambs/100 ewes) c o r r e s p o n d digestibility  of about  ewes c o r r e s p o n d about  40%.  heavily  range.  the q u a l i t y forage  versus  of  and  their  degrades the  expected  of  to r e s u l t  subsequent  summer due  The  o f g r a z i n g on  impact  the p o p u l a t i o n and  size,  the degree of  function  of  density-independent negative obvious  effect  Wishart  (1978) f o u n d  related negative  degrade  which  in  amount o f which  winter the  of t h e  vary  best  (Arnold  lamb c r o p s  range w i l l  snow d e p t h on study  (1978) and  and  be  ewes.  depending  food  operating.  Nichols  a  t h a t lamb p r o d u c t i o n  of d e n s i t y on  the w i n t e r  was by  Hoefs  appears to range.  lamb p r o d u c t i o n  and  The  a l s o reported (1978).  on  available,  is primarily  lamb p r o d u c t i o n was  for  sheep  Thus b o t h d e n s i t y - d e p e n d e n t  t o f o r a g e q u a n t i t y on impact  forage  nutrition  initial  of  removing the  remaining  i n lower  factors will  i n the present  S m i t h and Brink  of  Stone's  Heavy g r a z i n g  range l i m i t a t i o n  snow d e p t h s .  by  available  to poorer  the  forage  lambs/100  cows s i m i l a r l y  forage  the  of 60  values  were t h e v a l u e s  of  time  1976). the  lowest  estimated  values  s h e e p and  Stobbs  reported  forage d i g e s t i b i l i t y  range over  quality  t o an  ungrazed areas  l e a v i n g only poor  1960a, Chacon and  w o u l d be  estimated  Domestic  The  whereas v a l u e s  These d i g e s t i b i l i t y  grazed  winter  t o an  35%  range of  and be  The  i s reported  152  by Woodgerd The  (1964) and  S m i t h and  Wishart  p r e d i c t e d lamb:ewe r a t i o  (1978).  following a mild  winter  (60-65/100) d u r i n g w h i c h g r a z i n g i n t e n s i t y  was  low  comparable  and  1981  t o the observed  Toad M o u n t a i n .  The  values  f o r 1980  p r e d i c t e d lambiewe r a t i o  w i n t e r s , when g r a z i n g p r e s s u r e was overestimate Mountain  compared  i n 1982  disparity  may  and  to the  indicate  i n t e n s e , was  results  Churchill  for  i n 1981  t h a t the  for  an  Fertilizer  and  1982.  relationship  This  in Figure  lamb m o r t a l i t y i n p o o r c o n d i t i o n s .  Alternatively,  the  the m a t e r n a l on  nutrition  the b a s i s of  could  result  sufficient limited  from  lamb c r o p s based  forage  survive  i n the  the winter  l a c k of  unable  forage  w o u l d make t h e  indicate was  that  predicted  situation to o b t a i n a  C o n s i d e r i n g the almost  total  winter  this  study  ranges  i n 1982,  Overall,  observed  were c o n s i s t e n t w i t h p r e d i c t i o n s  nutrition  d u r i n g the p r e v i o u s  t h a t no  winter.  lamb s h o u l d be a b l e  because a forage d i g e s t i b i l i t y  i n a 30%  33  f o o d t o meet even t h e i r c a p a c i t y -  from  model p r e d i c t s  would r e s u l t or  being  than That  seems t o be q u i t e l i k e l y .  on m a t e r n a l  The  the a n i m a l s  q u a n t i t y of  possibility  even p o o r e r  forage d i g e s t i b i l i t y .  i n t a k e needs.  r e m o v a l of  lamb p r o d u c t i o n may  was  on  severe  underestimates  lower  was  weight  resulting  situation  loss. from  Poorer  heavy  even w o r s e .  of  quality  selective Mule d e e r  to 40%  forage  grazing d i e when  153  they  l o s e about  al.  1977).  Ball's  28%  of t h e i r  However, a c o m p a r i s o n  s h e e p lambs  June weights suggests  (27-39 kg;  of Stone's  that  a 30%  survive high  in size  typically et  weight  (Appendix  from  weights  B u n n e l l and O l s e n  s h e e p and  Reported  range  Stone's  II).  1976)  (19.1-30.4  l o s s may  be  with  kg)  tolerable  sheep a r e  Certainly  of  to  almost  lambs d i d  r a t e s were q u i t e  lamb w i n t e r m o r t a l i t y  30-50% ( H o e f s and  Cowan  rates  1979,  Simmons  a l . 1981). Although  lamb m o r t a l i t y  density  and  are not  well quantified.  nutritionally  winter m o r t a l i t y  rate  under heavy v e r s u s  of  light  However, i f we 40%  respectively.  A subsequent  o l d s or about The  population balance  growth.  36  (i.e.,  crop  50 v s  60  yearlings/ewe mortality  r a t e of  w o u l d l e a v e 27  v e r s u s 32  two-year-  16  female  recruits The  lesser  the a d u l t m o r t a l i t y  i f an  average  yearling  a population decline.  severe  relationships  t o t h e p r e d i c t e d lamb  i s 30 v e r s u s  13 v e r s u s  h i g h e r number o f  partly  a p p l y an  grazing pressure  result  (Simmons e t a l . 1981)  i s probably at least  dependent, these  lambs/ewe) t h e  in  of J a n u a r y  the w i n t e r a l t h o u g h m o r t a l i t y  (22-55%).  (deCalesta et  sheep y e a r l i n g s  winter  lambs b e c a u s e D a l l ' s identical  body w e i g h t  absolute lack  recruits/100 adult  would r e s u l t number  r a t e of  The  in  would  d e c l i n e would be  of food  i n winter  ewes.  slight  is insufficient  15% and  10%  to  result  even more  l e d t o even  154  lower lamb p r o d u c t i o n .  These rough c a l c u l a t i o n s o u t l i n e  the way i n which density-dependent s e l e c t i v e g r a z i n g regulate population pregnancy.  However, t h i s simple  density-independent other  growth by way of ewe n u t r i t i o n  variability  regulatory factors.  could  during  p a t t e r n w i l l be masked by i n winter  s e v e r i t y and  155  MANAGEMENT OF Stone's  sheep h e a v i l y g r a z e  ranges which reduced  results  lamb c r o p .  i n severe  improving  any  sheep.  range.  and  Burning  productive  However, t h e s e  are  of  are  severely  the v a l u e  sheep.  In t h e  burned  r a n g e was  winter,  the  one  wind-blown and  food a v a i l a b l e . be  directed  which are  This  where  available  future burning  which w i l l  f o r Stone's subalpine, t o sheep i n  Although  a very  burned  areas  be  abundant  efforts  should  wind-blown i n  r a n g e t h a t have a l r e a d y been b u r n e d s u g g e s t s be  feasible  compared  s h e e p do  from  i t .  Because the  i n t a k e r a t e of  bite  size  r a t h e r than  the  very  sparse  forage  large  s p r i n g r a n g e s c o n t a i n much more  unburned ranges,  food are  to the  not so  not  biting  the  forage  seem t o b e n e f i t g r e a t l y sheep i s l i m i t e d  rate,  ranges with  n e c e s s a r i l y b e t t e r than l o n g as  that  endeavour.  than  abundant  by  problem  areas  not  such  used  The  t h i s may  of  at  range  winter. of  rarity  directed  t o b e n e f i t from t h e  Therefore,  towards areas  be  range b u r n i n g  exceptional area  sheep appeared  limiting.  u s u a l l y u n a v a i l a b l e to  b e c a u s e of d e e p snow. of  and  provide  subalpine  grassland areas  areas  winter  problems  not  should  sheep i n w i n t e r limits  limited  summer r a n g e s  h a b i t a t improvement  winter  produces very  forage  their  nutritional  S p r i n g and  abundant, h i g h q u a l i t y Therefore,  STONE'S SHEEP  food  very  ranges  i s of h i g h  by  with  quality  156  and  the absolute q u a n t i t y i s not l i m i t i n g .  burning  t o produce  Therefore,  s p r i n g range does not appear  t o be  justi f ied. Although great  value  range b u r n i n g  t o Stone's sheep,  d e t r i m e n t a l and p r o b a b l y elk. be  I f range b u r n i n g  valleys.  super-abundant and  burned areas  b e n e f i t s other  forage  i n the area,  i t .  Even  i s no r e a s o n  lichens small  for caribou.  by u n g u l a t e s  support  Fertilization  the q u a n t i t y or q u a l i t y  by c l i m a t i c  extensive  that  burning vast  Forested  and p r o v i d e  areas be  arboreal  o f f o r e s t and  t h e g r e a t e s t number a n d  prohibitive.  Overall,  (Appendix  or n u t r i e n t c y c l i n g  factors.  fertilization  range i s p r o b a b l y not  i n the a l p i n e f a i l e d of forage  because p l a n t p r o d u c t i o n limited  produced  of w i l d l i f e .  Improvement o f a l p i n e w i n t e r feasible.  burning  e t c . , a n d may  Therefore, a mixture  b u r n s would p r o b a b l y  diversity  i f range  t o expect  provide habitat f o r furbearers, birds, cover  i t would  i n Delano v a l l e y  are s u p e r i o r t o small burns.  used as thermal  as  f a r b e y o n d t h e needs o f t h e s h e e p  which used  there  s p e c i e s such  s m a l l e r burns r a t h e r than  The s m a l l b u r n  mountain goats  was b e n e f i c i a l ,  i t i s n o t i n any way  i s continued  a d v i s a b l e t o produce  entire  d o e s n o t seem t o be o f any  to increase  I I I ) , probably processes are  A l s o , t h e c o s t o f any  program would l i k e l y the value of h a b i t a t  be improvement  157  p r o g r a m s a p p e a r s t o be in  this  extremely  d e s t r u c t i o n i s not  sheep p o p u l a t i o n s reservoirs range.  with  w h i c h may  the  sheep  a m a j o r t h r e a t t o most  exception  flood  critical  of h y d r o - e l e c t r i c subalpine,  Stone's sheep a c c l i m a t i z e v e r y  disturbances  such as  are  t o c a u s e any  unlikely likely  t o be  access  t o new  strict  law  to  areas.  the  increase  observed  been p r o p o s e d  during  this  study  to escape  mountain  sheep.  restricted  severity.  ranges.  The  and  by  access  recently to  i n the a r e a .  high as  However,  have a m a j o r attempts because  the  i n other  Adult  s t u d i e s of  lamb s u r v i v a l  sheep encounter  was  severe  t o h i g h d e n s i t i e s on  Therefore,  survival  r a t e s c a u s e d by p r e d a t o r  increase  the  negative  improved  d e a l t with  A l l predation  Lamb p r o d u c t i o n  problems r e l a t e d winter  problem  into precipitous terrain.  r a t e s a p p e a r e d t o be  nutritional  to  were u n s u c c e s s f u l  survival  to winter  major  controlling  that predators  sheep p o p u l a t i o n s .  s h e e p were a b l e  related  related  or p r e f e r a b l y by  good e v i d e n c e  to  The  T h i s p r o b l e m c o u l d be  c o n t r o l has  spring  Such d e v e l o p m e n t s  s e r i o u s harm.  S t o n e ' s sheep p o p u l a t i o n s  on  well  mines.  increased poaching  enforcement  i s no  effect  r o a d s and  areas.  Predator  there  f o r Stone's  area.  Habitat  is  limited  any  improvement  c o n t r o l would  in  only  i m p a c t s o f h i g h d e n s i t i e s on  winter  158  ranges.  It  any  sheep.  more  i s u n l i k e l y that  Trophy h u n t i n g significant  impact  of  large  on  the  the  winter  r a n g e s can  rams p r o b a b l y  population  has  no  numbers.  There  more t h a n enough mature rams t o b r e e d a l l t h e very  s k e p t i c a l of  the  hypothetical  arguments  t r o p h y h u n t i n g p r o p o s e d by  Geist  is  Shackleton  s u p p o r t e d by  Montana  ( J . Ford  detrimental  ensuring  hunting  that  rams.  protecting  small  a v e r a g e age  the  objective  Also,  find large  year.  I t would be  sheep r a t h e r  i s being  effectively  by  i n the  more l o g i c a l  than the  age  Also,  quotas since  not  be  resident rams  hunters  s i z e of involved  or  area  met  by  greater the the  t o base q u o t a s  since  on  i t is  free-ranging  sheep k i l l e d  by  sheep  resident  in c a l c u l a t i n g o u t f i t t e r  hunters shoot  (Hurd and  large  b a s e d on  outfitting  accurately.  hunters should  full-curl  quotas are  t o e x p e c t h u n t e r s t o age the  primarily directed to produce  outfitter  sheep k i l l e d  s i z e of  demand by  to  work i n  continue  rams f r o n h u n t i n g  of  younger  am  skepticism  numbers o f  are  unreasonable  and  This  failed  I  against  (1973) and  reduced  regulations  populations  This  regulations.  previous  comm.) w h i c h  ewes.  are  population.  Therefore,  trophy  pers.  e f f e c t s r e l a t e d to  rams i n t h e  at  r e s u l t s of  (1970).  support  significantly  Masters unpublished).  is sufficiently  great  that  smaller Present  most rams  are  159  probably k i l l e d w i t h i n a year or two size.  of reaching  legal  T h e r e f o r e , to produce l a r g e trophy rams you must  p r o t e c t smaller rams u n t i l  they reach that  size.  The major c o n t r o v e r s y i n s e t t i n g hunting r e g u l a t i o n s i s d i v i d i n g the k i l l residents.  between r e s i d e n t s and guided non-  In terms of economic b e n e f i t s to the area  and  the p r o v i n c e , the value of a sheep taken by a guided nonresident  i s f a r g r e a t e r than a sheep k i l l e d by r e s i d e n t s .  However, p o l i t i c a l pressure by r e s i d e n t hunters leads to p r o g r e s s i v e l y lower quotas  f o r non-resident hunters.  a debate i s beyond the r o l e of a w i l d l i f e b i o l o g i s t decide.  Such to  160  CONCLUSIONS  - o r d e r of c o n c l u s i o n s c o r r e s p o n d s t o h y p o t h e s e s p r e s e n t e d in  Introduction  Forage q u a n t i t y  1)  forage q u a l i t y  was was  much g r e a t e r similar  on b u r n e d  on b u r n e d and  ranges but  unburned  ranges  2)  Q u a n t i t y of food unburned  i n t a k e was  similar  on b u r n e d  and  r a n g e s f o r most o f t h e y e a r a l t h o u g h q u a l i t y  began t o i n c r e a s e a few d a y s e a r l i e r  on b u r n e d  spring  range.  3)  Sheep s e l e c t e d available  forage.  restricted  4)  Availability  Quality  o f i n t a k e was  quality  of a v a i l a b l e  not s u p e r i o r herbage  appeared  severely  migration  to the  average  range.  affecting  t o be more i m p o r t a n t t h a n  i n determining food  Altitudinal  on t h e  and c h e m i c a l f a c t o r s  palatability quality  was  nutritious  by snow i n w i n t e r .  Structural  5)  r a n g e s w i t h t h e most  selectivity.  t o a r e a s where t i l l e r  length  161  was a b o u t  10 cm p r o v i d e d  sheep t o m a i n t a i n quality  forage.  the opportunity  t h e maximum  intake rate of high  However, s h e e p d i d n o t a p p e a r t o  f e e d a t t h e maximum p o s s i b l e i n t a k e  Foraging  time  f o r the  and b i t i n g  rate.  r a t e d i d not vary  with  changes i n forage q u a n t i t y .  Foraging  time  and b i t i n g  b u r n e d and u n b u r n e d  related  nutrition.  winter.  were  D a t a were i n a d e q u a t e  ranges.  range than  rams was g r e a t e r on b u r n e d  on u n b u r n e d r a n g e b u t t h i s e a r l y  by t h e t i m e  rams were s h o t  disparity  by h u n t e r s .  p r o d u c t i o n was h i g h e r a n d p a r a s i t e l e v e l s were for  to  a n d body g r o w t h between b u r n e d a n d  Horn growth o f y e a r l i n g  was l o s t  removed a l l t h e  and P r o t o s t r o n q y l u s l e v e l s  to winter  compare h o r n unburned  range  forage during a severe  Lamb p r o d u c t i o n  between  range.  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Grazing succession  game a n i m a l s .  bases of  112: 627-631.  A. McLean, R. T u c k e r , a n d R. R i t c e y . between mule d e e r a n d c a t t l e  s a g e b r u s h range  Woodgerd,  Branch,  of the Environment,  Assessment  1978.  Interactions  Manage.  landscapes of  Columbia.  Vesey-Fitzgerald,  Westoby, M.  The s o i l  Resource A n a l y s i s  Ministry  Michigan deer.  East  1978.  in British  Columbia.  1979.  on b i g  J . Range  32: 299-304.  1964.  Population  on W i l d h o r s e I s l a n d .  dynamics of b i g h o r n  J . W i l d l . Manage.  sheep  28: 381-391.  176 A p p e n d i x I.  B i r d s and Mammals S i g h t e d i n the Toad R i v e r A r e a .  An a s t e r i c k (*) i s u s e d t o denote s p e c i e s w h i c h a r e beyond t h e i r normally reported range. Birds Common l o o n Horned grebe W h i s t l i n g swan Canada goose Mallard Pintail Green-winged t e a l Cinnamon t e a l * A m e r i c a n widgeon Shoveler Scaup B a r r o w ' s goldeneye Bufflehead Oldsquaw H a r l e q u i n duck Surf scoter Ruddy duck Common merganser Goshawk S h a r p - s h i n n e d hawk R e d - t a i l e d hawk Golden e a g l e Bald eagle Harrier Peregrine falcon Kestrel B l u e grouse S p r u c e grouse R u f f e d grouse Willow ptarmigan Sora Killdeer Greater yellowlegs Lesser yellowlegs Spotted sandpiper Snipe Herring g u l l G r e a t horned owl Common nighthawk Belted kingfisher Flicker P i l e a t e d woodpecker* Y e l l o w - b e l l i e d sapsucker H a i r y woodpecker N o r t h e r n t h r e e - t o e d woodpecker Eastern kingbird*  S a y ' s phoebe E a s t e r n phoebe Least f l y c a t c h e r T r a i l l ' s flycatcher Horned l a r k Tree swallow Bank s w a l l o w Barn swallow V i o l e t - g r e e n swallow C l i f f swallow Gray j a y Raven Black-capped chickadee B o r e a l chickadee Dipper Robin Varied thrush Townsend's s o l i t a i r e Swainson's thrush Hermit thrush Mountain b l u e b i r d Water p i p i t Cedar waxwing Bohemian waxwing Northern shrike Starling Yellow warbler Yellow-rumped warbler Townsend's w a r b l e r Wilson's warbler B l a c k p o l l warbler Yellow-headed b l a c k b i r d * Rusty b l a c k b i r d Brown-headed c o w b i r d Gray-crowned r o s y f i n c h Common r e d p o l l Hoary r e d p o l l Pine s i s k i n Savannah sparrow Oregon j u n c o Tree sparrow C h i p p i n g sparrow Golden-crowned sparrow White-crowned sparrow V e s p e r sparrow Song sparrow  177  Birds cont'd Lapland longspur Smith's lonspur Snow bunting Mammals L i t t l e brown bat Snowshoe hare Woodchuck Hoary marmot Red squirrel Least chipmunk Flying squirrel Beaver Deer mouse Jumping mouse Porcupine Wolf Coyote Red fox Black bear Grizzly bear Marten Short-tailed weasel Lynx Cougar* Mule deer Elk Moose Caribou Mountain goat Stone's sheep  Myotis lucifugus Lepus americana Marmota monax M. caligata Tamiasciurus hudsoriicus Eutamias minimus Glaucomys sabriiTus Castor canadensis Peromyscus mamculatus Zapus hiidsomcus Erithizon dorsatum Canis lupus C. latrans Vulpes vulpes Ursus americanus U. arctos Martes americana Mus tela ermmea Lynx lynx Felis concolor Odocoileus hemionus Cervus canadensis Alces alces Rangifer tarandus Oreamnos americanus Ovis d a l l i  178  APPENDIX I I  BODY WEIGHTS AND Published  data  are  sparse.  for  4 rams and  1 ewe;  Geist  of S t o n e ' s sheep  (1978) gave  measurements  (1971) p r e s e n t e d  f o r 2 rams and  (1974) s u g g e s t e d  than D a l l ' s  STONE'S SHEEP  on body measurements  Cowan and G u i g u e t  measurements Banfield  MEASUREMENTS OF  1 ewe.  that  Geist  w e i g h t s and  (1971) and  S t o n e ' s s h e e p were  sheep but noted t h a t  unequivocal  larger  evidence  was  lacking. W e i g h t s and m e a s u r e s p r e s e n t e d h e r e a r e f r o m s h e e p captured mineral  i n t h e l a t e J u n e and e a r l y lick.  Okanagan Dall's and  Also  July  at C h u r c h i l l  b i r t h w e i g h t s o f 3 lambs a t t h e  Game Farm a r e i n c l u d e d .  s h e e p and r e g r e s s i o n s  C o m p a r i s o n s a r e made t o  between  linear  measurements  body w e i g h t s a r e p r e s e n t e d .  RESULTS AND  DISCUSSION  The b i r t h w e i g h t s o f c a p t i v e , ± 0.4  kg, N = 4) were  sheep i n the w i l d early  July,  t o w e i g h t s of newborn  (3-4 kg, B u n n e l l and O l s e n  when t h e w i l d  6 weeks o f a g e , t h e i r variable.  similar  S t o n e ' s s h e e p lambs  S t o n e ' s lambs were  s i z e s and w e i g h t were  This variation  sample b e c a u s e many o t h e r  was  (3.3  Dall's  1976).  In  between  4 and  extremely  n o t s o l e l y due t o t h e s m a l l  lambs o b s e r v e d , b u t n o t  179  captured, captured  were c o m p a r a b l e t o e x t r e m e s o f s i z e among t h e 3 lambs.  (different result  Cause o f t h e v a r i a t i o n  ages or d i f f e r e n t  i n smaller  adequate  size  sized  i s n o t known  growth r a t e s ) ,  lambs  failing  to survive the winter  but i t c o u l d  t o grow t o an  (Bunnell  1980).  F e m a l e y e a r l i n g s were a b o u t 46% o f t h e a v e r a g e w e i g h t o f a d u l t ewes.  Male y e a r l i n g s tended to-be l a r g e r t h a n  f e m a l e y e a r l i n g s i n a l l w e i g h t s and measurements, there  was  a great  d e a l of o v e r l a p .  Adult  ewes were a b o u t  75% o f t h e w e i g h t o f t h e a d u l t S t o n e ' s ram w e i g h e d by G e i s t Bunnell  weight  (77.3  kg)  (1971).  and O l s e n  measurements  but  (1976)  reported  the f o l l o w i n g  f o r a d u l t , D a l l ' s s h e e p ewes ( x ,  (48.8 kg, 46.4-50.5),  35-39), c h e s t  girth  appear n e a r l y  identical  hind  (108.5 cm,  foot length  105-112).  range): (37.1  Stone's sheep  i n w e i g h t and s i z e  t o D a l l ' s sheep  (Table  1).  winter  o r e a r l y s p r i n g and t h e S t o n e ' s s h e e p were  during  summer, D a l l ' s s h e e p may  (allowing foot  B e c a u s e t h e D a l l ' s s h e e p were w e i g h e d  f o r over-winter  l e n g t h s d i d not d i f f e r  apparent d i f f e r e n c e i n chest likely between  due  be m a r g i n a l l y  weight l o s s ) . between  during weighed  heavier  However,  hind  the subspecies.  g i r t h measurements  t o a d i f f e r e n c e i n measurement  studies.  cm,  was  techniques  The most  Table 1.  Body measurements of Stone sheep.  Weight (kg)  Hind foot engA (cm) length (cm)  Chest girth (cm)  Chest height (cm)  49.6 ± 4.5 U.l - S5~8  37.9 ± 1.3 35 - 40  95.6 ± 3.8 87 - 101  49.3 + 3.7 40 - 54  15  15  Adult ewes X ± S.D.  Range  15  n  ^"J ?™, 1  Shoulder height (cm)  ^g *""^ length (on)  88.3 ± 6.4  26.4 ± 5.8  25.3 ± 6.5  70 - 95  17.5 - 38.0  17.0 - 39.0  15  15  1  length (cm)  15  Female yearlings  22.7  iTiT Range  35.9 ± 2.8  73  19 1 - 26.3  33 - 39  73 - 73  2  4  2  42.8  ±  2.1  41 - 45 d  73.5  ±  2.9  70 - 77 4  6.0 2.9 ±  2.0 - 9.0 4  5.3 3.7 ±  1.0 - 10.0 4  Male yearlings  *77D"  27.7 2.8  36.8 1.7  76.3 3.2  45.5 1.0  Range  24.5 - 30.4  35 - 39  4  4  73 - 79 4  45 - 47 4  72 - 80 4  11.5 ± 5.3 5.4 - 15.4  27.3 ± 3.8 23 - 30  52.5 ± 10.1 41 - 60  35.7 ± 4.9 30 - 39 3  55.7 ± 6.7 48 - 60 3  +  +  ±  ±  76.3 3.5 ±  8.1 ± 2.8 4.0 - 10.0 4  Male lambs (July) X±S.D.  Range n  3  3  3  3.3 ± 0.4  3  n  Ovis d a l l i dalli Adult ewes  2.0 - 11.2 4  0  Captive lamb birthweights X ± S.D.  8.4 ± 4.4  48.8  37.1  108.5  46.4 - 50.5  35 - 39  105 - 112  (from Bunnell and Olsen 1976)  3  3  181  Regressions  f o r Stone's sheep (Table 2) p r e d i c t e d body  weight from l i n e a r measurements with confidence l e s s than ± 2.5 kg at the mean.  Computed  l i m i t s of  confidence  l i m i t s were ± 1.5 kg, ± 1.8 kg, and ± 2.3 kg f o r chest g i r t h , horn l e n g t h , and h i n d foot l e n g t h , r e s p e c t i v e l y . The r e l a t i o n s h i p between h i n d foot l e n g t h and body weight was l i n e a r  f o r Stone's lambs and y e a r l i n g s , but there  was  no r e l a t i o n s h i p between these measurements i n a d u l t ewes.  182  Table 2.  Relationships between body weight and measurements of Stone sheep.  Regression equation  Sy.x  0.96  3.15  Chest girth (G)  W = -37.5  Longest hom  W = 18.7 + 1.13 HL  0.91  4.2  W = -32.8  0.92  2.6  length (HL)  Hind foot length (HF) (for lambs and yearlings)  + (0.88)G  r2  + 1.64 HF  183  REFERENCES CITED IN APPENDIX  B a n f i e l d , A.W.  1974. The mammals of Canada, U n i v e r s i t y  of Toronto P r e s s , Toronto.  B u n n e l l , F.L.  1980. F a c t o r s c o n t r o l l i n g  of D a l l ' s sheep.  Can. J . Z o o l .  ., and N.A. O l s e n .  lambing  period  58: 1027-1031.  1976. Weights  and growth of  D a l l ' s sheep i n Kluane Park, Yukon T e r r i t o r y . Can. F i e l d Nat.  90: 157-162.  Cowan, I.McT., and C.J. Guiguet. B r i t i s h Columbia.  1978. The mammals of  B.C. P r o v i n c i a l Museum Handbook,  V i c t o r i a , B.C.  G e i s t , V.  1971. Mountain  evolution.  sheep.  A study i n behavior and  U n i v e r s i t y of Chicago P r e s s .  Chicago.  184  APPENDIX I I I  THE EFFECT OF BURNING  AND F E R T I L I Z A T I O N ON STONE'S SHEEP RANGES  Subalpine the  spring  forest  I  are regularly  i n t h e Toad R i v e r a r e a  e n c r o a c h m e n t a n d t o improve  some a l p i n e Fish  g r a s s l a n d ranges  a r e a s have r e c e n t l y  and W i l d l i f e  attempted  Branch  i n an e f f o r t range  been  fertilized  t o e v a l u a t e the value of these  monitoring  the e f f e c t  ii)  conducting  alpine  Burning  in alpine  because these  to prevent Also,  by t h e  sheep  range.  t e c h n i q u e s by:  of a s u b a l p i n e g r a s s l a n d  fertilization areas  during  quality.  t o improve S t o n e ' s  i)  burned  fire  experiments.  i s not a v i a b l e  areas a r e not able t o c a r r y  technique  a fire.  METHODS  SUBALPINE The  BURNING  subalpine, g r a s s l a n d slopes of F e r t i l i z e r  were b u r n e d selected  by l o c a l  r e s i d e n t s i n mid-May, 1981.  f o u r u n b u r n e d a r e a s and f o u r a d j a c e n t  Mountain I  burned  185:  a r e a s on t h e s l o p e s a n d measured a r e a s by c l i p p i n g 0.25 m Forage  2  plots  s a m p l e s were c o l l e c t e d  analysis.  Soil  plant  biomass  t h r o u g h o u t t h e summer.  for protein  s a m p l e s were c o l l e c t e d  f r o m t h e s e a r e a s and a n a l y z e d  i n these  and p r o x i m a t e  ( t o p 10 cm o f s o i l )  f o r n i t r a t e , phosphorous,  p o t a s s i u m , and s u l p h u r .  ALPINE  FERTILIZATION  E x p e r i m e n t J_ In  1980, two 0.25 ha p l o t s  i n the alpine  Fertilizer  M o u n t a i n were f e r t i l i z e d  fertilizer  (17% n i t r a t e ,  in  early  June, p r i o r  measured  analyzed  t o new p r o d u c t i o n .  g/m  2  b i o m a s s was  u n f e r t i l i z e d areas i n  plots.  These a r e a s  F o r a g e samples  were  were  2  1982, two 500 m  water  soluble  g/m .  Plant  2  plots  i n the alpine  zone o f Tower  w i t h 27-3-3 f e r t i l i z e r  N, 6.8% w a t e r  insoluble  b i o m a s s was measured  i n e a r l y August.  protein  Plant  of 5  a n d f i b r e i n 1980 a n d 1981.  M o u n t a i n were f e r t i l i z e d  plots  2  i n 1981 a n d 1982.  for protein  Experiment  2  17% ammonium) a t a r a t e  by c l i p p i n g 0.25 m  sampled a g a i n  In  w i t h 34% n i r o g e n  on t h e s e a r e a s and a d j a c e n t  mid-August  zone o f  (19.5%  N) a t a r a t e  by c l i p p i n g 0.25  o f 13 m  2  F o r a g e s a m p l e s were a n a l y z e d f o r  a n d i_n v i t r o d r y m a t t e r d i g e s t i b i l i t y .  Soil  186  samples (top 10 cm) were c o l l e c t e d and analyzed f o r N, P and K.  total  187,  DISCUSSION  SUBALPINE BURNING The  spring fire  g r a m i n o i d s and similar end  on  of  the  difference versus was  f o r b s but  b u r n e d and growing  (Table  (Table  d i d not  burning  may  2).  no  At  the  f o r b s on  (ADF  and  soil  burned  protein) and  mineral  different  on  burned versus  carryover  on  these  about  0.6  burn s o i l  be  balanced  p r e v i o u s l y mentioned Mountain  p h o s p h o r o u s and i n the  was  significant  between b u r n e d  Similarly,  2  organic  interval  by  material.  soil  levels unburned  i n the  t h e s i s (Table t o have  potassium  levels  than  w h i c h may  this  slope.  be  in spring fires frequent  levels  n i t r o g e n - f i x a t i o n by  tended  on  The Very  nitrogen  soils  vicinity  slopes  g of n i t r o g e n / m .  eventually deplete  l o s s can  burning  was  different  the winter  usually  areas  there  1).  of  3).  would v o l a t i l i z e  Fertilizer  l a t e June p l a n t biomass  Forage q u a l i t y  significantly  Burning  As  production  i n t h e amount o f g r a m i n o i d s and  unburned p l b t s  the  season  significantly  were not  by  s e t back t h e  unburned p l o t s ( T a b l e  unburned p l o t s .  not  plots  initially  unless  legumes.  11),  higher  soils  related  from to the  other frequent  188 Table 1.  Graminoid and forb production on burned versus unburned p l o t s on F e r t i l i z e r mountain following a spring burn. 2 Graminoid biomass (g/m )  X  8.7  June 17  37.7  July 4  62.8  July 26  58.4  August 12  55.5  + + + + +  X  - SE*  burned  May 25  2 Forb biomass (g/m )  unburned  1.5  18.9  8.7  38.9  17.6  66.0  9.7  44.0  13.7  53.0  + + + + +  burned  - SE unburned  0.9  0.0  18.8  6.8  20.1 - 6.9  35.5  10.0  52.0 - 17.2  30.8  5.9  20.0 - 11.2  34.8  9.9  16.0 - 4.7  26.3  + + + + +  0.8 11.5 6.0 8.0 7.9  * n = 4 f o r a l l samples  Table 2.  Protein and ADF levels i n graminoids on burned versus unburned p l o t s on F e r t i l i z e r mountain following a spring burn.  Crude Protein (I)  J burned  (4)  ADF  J  SE unburned  n  - SE  burned n  unburned n  May 25  21.6  2  19.9  2  23.9  2  29.3 - 0.7  July 4  14.0 - 1.9  4  13.5 - 3.1  4  32.2 - 1.5  4  30.1 - 2.2  July 26  9.7 - 1.1  4  7.9 - 0.3  32.1 - 0.9  4  33.4 - 0.8  Table 3. Comparison of s o i l nutrient levels on burned versus unburned subalpine plots and f e r t i l i z e d versus unfertilized alpine plots. (X + SE). total N  K  nitrate  n  Subalpine burned  u  17.0 - 2.5  370 - 99.1  7.8 - 0.64  4  unburned  u  16.7 - 1.7  393 - 78.0  7.1 - 0.62  4  Alpine fertilized  0.65 - 0.1  0.8 - 0.5  70 - 39.0  4  unfertilized  0.43 - 0.1  u  70 - 39.0  4  u = undetectible, less than 1.0 ppm.  00  o  190  Overall, ranges  was  quality. by  the  not  not  of  spring  burning  beneficial  poplars.  burning  too  i f burning  impossible  should  d i d improve  to  soils.  range  quality,  i t would  a r e a s of S t o n e ' s  winter  (Figure 4  in  spring  to carry  grazed  i n t h e s i s ) d i d not c o n t a i n enough a fire.  These a r e a s  remained  whereas the dead c a r r y o v e r i n the ungrazed adequate to support  the  be  sheep  b e c a u s e t h e a r e a s w h i c h were h e a v i l y  in  range  be  f r e q u e n t l y in order  t o improve c r i t i c a l  range  subalpine  t h e a r e a s as g r a s s l a n d  Caution  n i t r o g e n d e p l e t i o n of the  Even  of  or d e t r i m e n t a l to  i t does m a i n t a i n  encroaching  e x e r c i s e d by  winter  clearly  However,  killing  prevent  effect  fuel  unburned  areas  was  fire.  ALPINE F E R T I L I Z A T I O N Fertilized  p l o t s d i d not  graminoids  or  experiment  (Table 4 ) .  significantly  f o r b s than  different  tended  s u p e r i o r on  (Table In  in either  plots was  fertilized  in either  not  fertilized  experiment  and  although  plots  more  quality  i n experiment  2  5). experiment  significantly and  quality  between  plots  significantly  unfertilized  Forage  unfertilized t o be  produce  2,  higher  soil  mineral levels  i n the  phosphorous tended  t o be  fertilized higher  were  plots  not but n i t r o g e n  (Table 3 ) .  Although  191  Table 4.  Graminoid and forb production on f e r t i l i z e d and u n f e r t i l i z e d alpine p l o t s (X * SE). Graminoid Biomass (g/m )  Forb Biomass (g/m )  2  fertilized  unfertilized  fertilized  unfertilized  Experiment 1 August 1980,p l o t A  16.1  plot B  10.5  August 1981, p l o t A  8.4  plot B  6.9  August 1982,p l o t A  7.4  + +  + +  +  1.8  21.4  3.4  16.2  3.3  7.0  1.6  19.3  3.9  5.1  0.7  8.9  3.1  13.4  + +  +  +  2.9  22.6  +  3.7  18.7  +  6.3  3.8  35.7  +  7.6  39.8  +  6.2  3.6  23.1  9.3  19.1  2.6  26.2  3.6  12.6  2.0  23.9  7.6  22.2  3.1  24.7  +  6.7  13.3  +  4.6  2.4  53.4  +  21.2  20.5  +  5.9  + +  +  + + +  4.8 5.1 2.4  Experiment 2 August 1982,p l o t A  5.4  plot B  6.1  + +  + +  n = 5 f o r a l l samples  Table  5.  Forage q u a l i t y _ o f graminoids from f e r t i l i z e d and u n f e r t i l i z e d alpine p l o t s . (X - S5)  Experiment 1  Crude Protein (t)  August 1980, f e r t i l i z e d unfertilized August 1981 f e r t i l i z e d unfertilized Experiment 2  10.0 9.0 10.5 11.4  + + +  0.5  26.8  0.4  29.1  0.9  27.3  0.4  25.2  Crude protein (t)  August 1982 f e r t i l i z e d unfertilized n » 4 f o r a l l samples  _X__1%1  11.1 - 0.9 9.6 - 0.2  +  In v i t r o J M D (t) 60.8 * 2.2 54.2 - 3.7  193  the data i s i n c o n c l u s i v e , i t suggests that the l e v e l of fertilization  i n Experiment  s o i l n u t r i e n t l e v e l s and production.  2 was  beginning to i n c r e a s e  forage q u a l i t y but not  T h i s minor response  was  forage  probably not adequate  to be a s i g n i f i c a n t b e n e f i t to the sheep using the  range.  

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