Open Collections

UBC Theses and Dissertations

UBC Theses Logo

UBC Theses and Dissertations

Pregnancy rate and early lamb surviaval of California bighorn sheep (Ovis canadensis californiana, Douglas… Harper, William Lamont 1984

Your browser doesn't seem to have a PDF viewer, please download the PDF to view this item.

Item Metadata

Download

Media
831-UBC_1984_A6_7 H37.pdf [ 5.16MB ]
Metadata
JSON: 831-1.0096116.json
JSON-LD: 831-1.0096116-ld.json
RDF/XML (Pretty): 831-1.0096116-rdf.xml
RDF/JSON: 831-1.0096116-rdf.json
Turtle: 831-1.0096116-turtle.txt
N-Triples: 831-1.0096116-rdf-ntriples.txt
Original Record: 831-1.0096116-source.json
Full Text
831-1.0096116-fulltext.txt
Citation
831-1.0096116.ris

Full Text

PREGNANCY RATE AND EARLY LAMB SURVIVAL OF CALIFORNIA BIGHORN SHEEP (OVIS CANADENSIS CALIFORNIANA, DOUGLAS 1871) IN THE ASHNOLA WATERSHED, BRITISH COLUMBIA. By WILLIAM LAMONT HARPER B.Sc.(Zool), University of British Columbia, 1979 A THESIS SUBMITTED IN PARTIAL FLJIiFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE in THE FACULTY OF GRADUATE STUDIES (Department of Animal Science) We accept this thesis as conforming to the recfuired standard, . THE UNIVERSITY OF BRITISH COLUMBIA October 1984 ©William Lamont Harper, 1984 In presenting t h i s thesis i n p a r t i a l f u l f i l m e n t of the requirements for an advanced degree at the University of B r i t i s h Columbia, I agree that the Library s h a l l make i t f r e e l y available for reference and study. I further agree that permission for extensive copying of t h i s thesis for scholarly purposes may be granted by the head of my department or by his or her representatives. I t i s understood that copying or publication of t h i s thesis for f i n a n c i a l gain s h a l l not be allowed without my written permission. Department O f A m n w l fim'pnpp  The University of B r i t i s h Columbia 1956 Main Mall Vancouver, Canada V6T 1Y3 Date October 1fir DE-6 (.3/81) i i ABSTRACT The F l a t i r o n Mountain p o p u l a t i o n of bighorn sheep [Ovis  c a n a d e n s i s ] , with a h i s t o r y of low lamb r e c r u i t m e n t , was s t u d i e d to determine the t i m i n g of o f f s p r i n g l o s s e s , the n u t r i t i o n a l and di s e a s e s t a t u s of females, and the s i g n i f i c a n c e of s u c k l i n g behaviour, weather, and p r e d a t i o n on lamb s u r v i v a l . Pregnancy f a t e , determined by Doppler u l t r a s o u n d diagnoses, was 100% i n 10 a d u l t females captured i n mid to l a t e g e s t a t i o n . M o r t a l i t y of lambs belonging to tagged females was 64%, a l l o c c u r r i n g i n the f i r s t month postpartum. Of the f i v e females t h a t were observable throughout the lambing p e r i o d , three l o s t t h e i r o f f s p r i n g when the lamb was between f i v e and 21 days o l d . Adu l t females from F l a t i r o n Mountain were he a v i e r and had higher body c o n d i t i o n scores than a c a p t i v e r e s e a r c h herd with h i g h e r lamb p r o d u c t i o n , suggesting energy s t a t u s of F l a t i r o n females was s u f f i c i e n t f o r lamb s u r v i v a l . C o n c e n t r a t i o n s of selenium, copper, and z i n c i n the blood serum of F l a t i r o n females i n winter were m a r g i n a l l y d e f i c i e n t , based on domestic sheep v a l u e s . The one 9-month o l d lamb captured had very low l e v e l s of some blood m i n e r a l s . L i v e r and kidney c o n c e n t r a t i o n s suggest t h a t selenium i n a d u l t males was the onl y t r a c e mineral m a r g i n a l l y d e f i c i e n t i n t h i s p o p u l a t i o n . The onl y important pathogen i s o l a t e d from nasal swabs was p a r a i n f l u e n z a type-3 v i r u s , which was found i n 50% of the 12 females sampled i n l a t e w i n t e r . Although s e v e r a l storms i n v o l v i n g f r e e z i n g temperatures and s n o w f a l l o c c u r r e d during the i i i lambing p e r i o d , females with newborn lambs frequented lower e l e v a t i o n s c h a r a c t e r i z e d by a m i l d e r m i c r o c l i m a t e , and there was no obvious c o r r e l a t i o n between inclement weather and p e r i o d s of \ h i g h lamb m o r t a l i t y . The s u c k l i n g behaviour of F l a t i r o n lambs was s i m i l a r to t h a t of other p o p u l a t i o n s which, on average, had double the lamb p r o d u c t i o n of F l a t i r o n females. A n a l y s i s of predator s c a t s , mainly coyote, r e v e a l e d 24% by volume of t h e i r s p r i n g d i e t c o n s i s t e d of bighorn lambs. Based on the l a c k of s i g n i f i c a n t n u t r i t i o n a l , d i s e a s e , or c l i m a t i c f a c t o r s , and c o n s i d e r i n g the t i m i n g of lamb l o s s e s , coyote p r e d a t i o n was hypothesized to be the most l i k e l y f a c t o r l i m i t i n g lamb s u r v i v a l on F l a t i r o n Mountain. Research e f f o r t should be d i r e c t e d towards t e s t i n g t h i s c o n c l u s i o n b e f o r e management p r e s c r i p t i o n s are a p p l i e d . i v TABLE OF CONTENTS PAGE A b s t r a c t i i Table of Contents i v L i s t of Tables v i i L i s t of F i g u r e s v i i i L i s t of Appendices x Acknowledgements x i I n t r o d u c t i o n 1 Background and O b j e c t i v e s 1 Study Area 20 Methods 24 Capture and Data C o l l e c t i o n 24 Pregnancy Diagnosis 25 Blood and T i s s u e Samples 25 Aerobic B a c t e r i a and V i r u s Sampling 26 Weights and Measurements and Body C o n d i t i o n Scores 26 I d e n t i f i c a t i o n C o l l a r s and Eartags 27 Observation and Census of the P o p u l a t i o n 27 Census Technique 27 S u c k l i n g Behaviour 28 V C l i m a t o l o g i c a l S t a t i o n s 29 Predator Food Habits 30 S t a t i s t i c a l A n a l y s i s 31 R e s u l t s 3 3 Timing of O f f s p r i n g Losses 33 Pregnancy Rate 33 S u r v i v a l of Lambs from Tagged Females 33 N u t r i t i o n a l and Disease Status of Females i n Late G e s t a t i o n 38 Weights, Measurements and Body C o n d i t i o n Scores 38 Blood and T i s s u e Chemistry 40 Disease Incidence 42 P r o d u c t i o n and S u r v i v a l of O f f s p r i n g During the Lambing P e r i o d 43 C l a s s i f i c a t i o n Censuses of the F l a t i r o n Mt. P o p u l a t i o n 43 V o c a l i z a t i o n and Search Behaviour of Females 45 P o t e n t i a l F a c t o r s A f f e c t i n g Lamb S u r v i v a l 50 Weather During Lambing 50 S u c k l i n g Behaviour 53 D i r e c t Observations of Predators 54 Contents of Predator Scats i n S p r i n g 56 D i s c u s s i o n 58 Timing of O f f s p r i n g M o r t a l i t y 58 Pregnancy Rate 58 v i S u r v i v a l of Lambs from Tagged Females 60 N u t r i t i o n a l and Disease Status of Females i n Late G e s t a t i o n 61 Weights, Measurements, and Body C o n d i t i o n Scores 61 Blood and T i s s u e Chemistry 63 Disease Incidence 67 P r o d u c t i o n and S u r v i v a l of O f f s p r i n g During the Lambing P e r i o d 70 Lambing Chronology and P r o d u c t i o n i n Previous Years 70 P o t e n t i a l F a c t o r s A f f e c t i n g Lamb S u r v i v a l 73 Weather During Lambing 73 S u c k l i n g Behaviour 75 P r e d a t i o n 76 Conclus i o n s 82 Recommendations 84 L i t e r a t u r e C i t e d 87 Appendices 97 v i i LIST OF TABLES 1. Recent h i s t o r y of the Ashnola bighorn p o p u l a t i o n 2. Summary of y e a r l y maximum c l a s s i f i c a t i o n counts on F l a t i r o n Mountain i n the Ashnola s i n c e 1950 . 3. Pregnancy d i a g n o s i s , weights, and measurements of bighorn females captured on F l a t i r o n Mountain i n 1983 34 4. Blood chemistry of female bighorn from the Ashnola ... 35 5. Weights of C a l i f o r n i a b ighorn sheep from s o u t h - c e n t r a l B r i t i s h Columbia 39 6. Trace mineral c o n c e n t r a t i o n s of l i v e r and kidney t i s s u e on a wet weight b a s i s from male and female bighorn from F l a t i r o n Mountain 41 7. Monthly maximum c l a s s i f i c a t i o n counts of bighorn sheep on the F l a t i r o n Mountain t r a n s e c t i n 1982 and 1983. R a t i o s i n parentheses of lambs, y e a r l i n g s , and males (2yr+) t o a d u l t females are a l s o shown based on y e a r l y maxima 46 8. S u c k l i n g behaviour of bighorn lambs f o r the F l a t i r o n Mountain p o p u l a t i o n between A p r i l 27 and June 11, 1983 53b PAGE 3 5 v i i i LIST OF FIGURES PAGE 1. (A) Y e a r l y maximum counts of females (2 years and older) on F l a t i r o n Mountain from 1960 to 1983. (B) R a t i o of lambs per a d u l t female from 1960 to 1983 based on y e a r l y maximu counts. See t a b l e 2 f o r a c t u a l values 6 2. Schematic diagram r e p r e s e n t i n g the process o f , and f a c t o r s a f f e c t i n g , p r o d u c t i o n and s u r v i v a l of bighorn lambs to one month of age 10 3. The study area on F l a t i r o n Mountain i n the Ashnola River watershed 21 4. P a t t e r n of i s o l a t i o n of tagged females, and the p a t t e r n of b i r t h and s u r v i v a l of t h e i r lambs on F l a t i r o n Mountain i n 1983 37 5. (A) P a t t e r n of o b s e r v a t i o n of newborn lambs on F l a t i r o n Mountain i n 1983. (B) P a t t e r n of o b s e r v a t i o n of a d u l t females on F l a t i r o n Mountain i n 1983 i n d i c a t i n g i s o l a t i o n of pregnant females duri n g the lambing p e r i o d 44 i x 6. S u r v i v a l of bighorn lambs on F l a t i r o n Mountain from June, 1982 to May, 1983 based on pregnancy d i a g n o s i s and maximum counts of lambs and y e a r l i n g s 47 7. Weather p a t t e r n s i n the Ashnola a t 1585 m (HT3) d u r i n g the 1983 lambing p e r i o d 51 8. P a t t e r n of o b s e r v a t i o n of newborn lambs on F l a t i r o n Mountain i n seven d i f f e r e n t years 71 X LIST OF APPENDICES Accuracy of Doppler u l t r a s o u n d i n d i a g n o s i n g pregnancy i n b ighorn sheep. Harper and Cohen ( i n p r e s s ) . J . W i l d l . Manage. D e s c r i p t i o n s of the c h a r a c t e r i s t i c s used to d e f i n e the Body C o n d i t i o n Score s c a l e used i n t h i s study ( a f t e r Russel e t a_l. 1969) . Trace mineral c o n c e n t r a t i o n s of l i v e r and kidney t i s s u e on a wet weight b a s i s form male and female bighorn from s o u t h - c e n t r a l B r i t i s h Columbia. Comparison of the c h a r a c t e r i s t i c s of those tagged females which s u c c e s s f u l l y r e ared a lamb to three months o l d , to those t h a t l o s t t h e i r lambs when they were l e s s than one month o l d . x i ACKNOWLEDGEMENTS My c o - s u p e r v i s o r s were Dr. D.M. Shackleton and Dr. R.M. T a i t , both of whom provided guidance and support throughout the p r o j e c t . The other members of my committee were, Drs. M.D. P i t t , F.L. B u n n e l l , and R.G. Peterson. Mr. R.C. L i n c o l n f i r s t suggested s t u d y i n g the Ashnola bighorn, and Dr. R.D.H. Cohen i n i t i a t e d the p r o j e c t . Dr. R.G. Lewis, of the P r o v i n c a l V e t e r i n a r y Pathology Laboratory, provided the analyses of blood, t i s s u e , and na s a l swab samples, f o r t r a c e mineral l e v e l s and di s e a s e i n c i d e n c e s . Dr. D. Rurak loaned me h i s Doppler u l t r a s o u n d device f o r p r a c t i s e i n the e a r l y stages of the p r o j e c t . Dr. D. Eastman allowed me to sample the Okanagan Game Farm r e s e a r c h herd, and provided u s e f u l s u g g e s t i o n s . Mr. P. Davidson k i n d l y p rovided unpublished data on t r a c e mineral l e v e l s of East Kootenay b i g h o r n . Many f r i e n d s , r e l a t i v e s , f e l l o w graduate s t u d e n t s , and s t a f f of the B.C. M i n i s t r y of Environment helped me out, both i n the f i e l d and i n the l a b . Mr. H.F. Newman, of the Keremeos-Cawston Sportman's x i i A s s o c i a t i o n , was always s u p p o r t i v e and i n t e r e s t e d i n the p r o j e c t . In two years a t o t a l of 25 hunters v o l u n t a r i l y submitted t i s s u e samples f o r mineral a n a l y s i s . My s i n c e r e thanks to a l l of you. Th i s p r o j e c t was a j o i n t undertaking of the U n i v e r s i t y of B r i t i s h Columbia and the B.C. M i n i s t r y of Environment. F i n a n c i a l support was provided by the Science C o u n c i l of B r i t i s h Columbia, the B.C. M i n i s t r y of Environment, and the U n i v e r s i t y of B r i t i s h Columbia. L o g i s t i c a l support was a l s o p rovided by the B.C. M i n i s t r y of Environment. I would e s p e c i a l l y l i k e to thank my wif e T e r r y , who took a year out to a s s i s t i n the m a j o r i t y of the f i e l d work, and who showed p a t i e n c e and understanding d u r i n g the w r i t i n g phase of the p r o j e c t . "When we c o n s i d e r . . . how soon some f i s h e s would f i l l the ocean i f a l l t h e i r ova became f u l l grown f i s h e s , we are tempted to say t h a t every organism, whether animal or ve g e t a b l e , i s contending f o r p o s s e s s i o n of the p l a n e t . . . Nature opposes to t h i s many o b s t a c l e s , as c l i m a t e , myriads of brute and a l s o human f o e s , and of competitors which may preoccupy the ground. Each suggests an immense and wonderful greed i n e s s and t e n a c i t y of l i f e . . . And each p r e v a i l s as much as i t does, because of the ample p r e p a r a t i o n s i t has made f o r the c o n t e s t . . - Henry David Thoreau March 22, 1861. 1 INTRODUCTION Background and O b j e c t i v e s The numbers of C a l i f o r n i a bighorn sheep (Ovis canadensis  c a l i f o r n i a n a ) i n the Ashnola watershed before the a r r i v a l of white men are unknown, but were probably l a r g e r than the present p o p u l a t i o n , based on r e p o r t s from e a r l y n a t u r a l i s t s . An Indian v i l l a g e was l o c a t e d near the confluence of the Ashnola and Similkameen R i v e r s and i t s i n h a b i t a n t s hunted the v a r i o u s p o p u l a t i o n s of bighorn i n the area. Led by Indian guides, the f i r s t white men to v i s i t the area i n 1886 and 1887 remarked on the g r e a t abundance of bighorn observed ( A l l e n 1912; Buechner 1960). When word of t h i s spread i n t e r n a t i o n a l l y , unregulated hunting, u n t i l 1909, d r a s t i c a l l y reduced the Ashnola p o p u l a t i o n (Blood 1961). Brooks (1923) a t t r i b u t e s the e x t i r p a t i o n of mountain sheep i n the dry i n t e r i o r of B.C. to the i n t r o d u c t i o n of r i f l e s to the Indians and the i n t r o d u c t i o n of d i s e a s e s from domestic sheep on bighorn range. During the p e r i o d from 1909 u n t i l 1955, w i t h the e x c e p t i o n of a s h o r t season i n 1947, a l l hunting of bighorn was f o r b i d d e n i n the southern i n t e r i o r of B.C. and s u r v i v i n g bighorn p o p u l a t i o n s i n c r e a s e d . T h i s i n c r e a s e continued a f t e r a male-only hunting season was i n t r o d u c e d , and the p o p u l a t i o n peaked at a minimum of 217 bighorn on F l a t i r o n 2 Mountain i n 1967 ( S c h e f f l e r 1973). A f t e r 1967, c l a s s i f i c a t i o n counts i n d i c a t e d t h a t the p o p u l a t i o n began to d e c l i n e , p r i m a r i l y as a r e s u l t of low lamb p r o d u c t i o n (Ramsay 1980). In the past 30 years many management s t r a t e g i e s have been a p p l i e d to the Ashnola bighorn, with the o b j e c t i v e of i n c r e a s i n g the p o p u l a t i o n to the l e v e l estimated to have e x i s t e d before the a r r i v a l of white men (R.C. L i n c o l n p e r s . comm.). These i n c l u d e d c a t t l e removal, f a l l and s p r i n g burning, predator c o n t r o l , winter f e e d i n g , mineral supplementation, water supplementation, and a n t i - h e l m i n t i c treatment (Table 1) . The reasons f o r a p p l y i n g these treatments were o f t e n due to r e t r o d u c t i v e reasoning, which i s not always r e l i a b l e because a l t e r n a t e hypotheses can be generated from the same s e t of f a c t s (Romesburg 1981). During the p e r i o d from 1970 to present, when most of these treatments were a p p l i e d , p r o d u c t i o n of lambs g e n e r a l l y decreased and c l a s s i f i c a t i o n counts averaged o n l y 26 lambs per 100 a d u l t females (n=13 y e a r s , Table 2). While there i s g r e a t v a r i a t i o n i n lambing success among North American mountain sheep p o p u l a t i o n s , 50 lambs per 100 females i s g e n e r a l l y c o n s i d e r e d adequate f o r p o p u l a t i o n growth (Lawson and Johnson 1982) . During t h i s p e r i o d of low lamb p r o d u c t i o n , the maximum number of a d u l t females on F l a t i r o n Mountain d e c l i n e d a t an average r a t e of 1.7 per year (Figure 1) . Bighorn sheep and t h e i r range h a b i t s have been s t u d i e d i n Table 1. Recent h i s t o r y of the Ashnola bighorn p o p u l a t i o n . Date F a c t o r s a f f e c t i n g the bighorn sheep on F l a t i r o n and C r a t e r Mts, Source 1861 e a r l y 1880'S 1887 1909 1912 1913 1919 1922 1924 1914-1950 1928 1947 1951-52 1952 1955 wagon road up the Ashnola R. s t a r t of c a t t l e g r a z i n g on bighorn winter ranges s t a r t of unregulated s p o r t and market hunting Blood 1961 Blood 1961 Blood 1961 bighorn herds c l o s e d t o hunting Blood 1961 s t a r t of domestic sheep g r a z i n g on winter ranges O.I.C. Gr a z i n g Reserve f o r bighorn on South Slope and C l i f f ' s Ridge s t a r t of horse g r a z i n g on bighorn winter ranges " v i r u s " from domestic sheep causing d i s e a s e i n bighorn domestic sheep removed from winter ranges 600 c a t t l e on a l l Ashnola winter ranges 400 c a t t l e on South Slope alone i n d i c a t e s o v e r s t o c k i n g s h o r t hunting season coyote c o n t r o l by poison b a i t c a t t l e numbers reduced to 150 male on l y hunting season begins (3/4 c u r l r e g u l a t i o n ) Blood 1961 & Demarchi 1965 Harper 1980 Demarchi 1965 Brooks 1923 Demarchi 1965 Demarchi 1965 Blood 1961 Blood 1961 Blood 1961 Blood 1961 Demarchi 196 5 4 Table 1. 1955 1957 1957-68 1969-76 1973 1974-83 1976-80 1977 1977 1978-81 1981 Continued. c a t t l e numbers i n c r e a s e to 300 Blood 1961 1982 1983 1984 poison b a i t s dropped by a i r c r a f t on mountain ranges c a t t l e numbers s t a b i l i z e at 340-345 c a t t l e removed predator c o n t r o l by poison b a i t , t r a p p i n g and shooting open season i s r e p l a c e d by L i m i t e d E n t r y Hunting s p r i n g burning on South Slope mineral b l o c k s (3001bs)and a n t i - h e l m i n t i c s (50 lbs) fed to bighorn on South Slope c a t t l e r e t u r n e d to Ashnola ranges (350 head) but do not graze on South Slope 300-800 kg of p e l l e t e d food supplements and a n t i -h e l m i n t i c s on South Slope f a l l burning of South Slope and surrounding ranges a d d i t i o n a l p e l l e t e d food supplement t o make up f o r burned winter range, no a n t i - h e l m e n t h i c s , but mineral mix added to f e e d . p e l l e t e d food supplements but no minerals or a n t i -helmenthics Number of permits f o r L i m i t e d E n t r y Hunting i n c r e a s e d but a 3/4 c u r l r e s t r i c t i o n i s now enforced Blood 1961 Blood 1961 & Demarchi 1965 Morrison 1972 Webster unpubl. f i e l d notes Ramsay 1980 Ramsay 1980 Harper 1980 C r a t e r - J u n i p e r C.R.M.P. Ramsay 19 80 Min. of E n v i r o n , f i l e s , P e n t i c t o n . Min. of E n v i r o n , f i l e s , P e n t i c t o n Min. of Environ, f i l e s , P e n t i c t o n B.C. L i m i t e d E n t r y Hunting Synopsis 84/85 Table 2. Summary of yearly maximum classification counts on Flatiron Mountain since 1950. See Figure 1 for graphical representation of number of adult females and lamb:female ratios. Females Males Lambs per Yearl. per Year Iambs Yearl. 2yr+ 2yr+ Female Female Source 1950 16 11 43 — .37 .26 Cowan 1951 1951 23 5 38 .60 .13 Cowan 1951 1960 35 15 54 71 .65 .28 Blood 1960, 1961, 1963. 1963 23 16 53 79 .43 .30 Demarchi 1965 1964 30 17 72 53 .42 .24 Demarchi 1965 1967 49 34 107 51 .46 .31 Scheffler 1973 1968 28 Silver 1971 1969 27 Silver 1971 1970 28 — 99 62 .28 — Spalding 1971 1971 27 13 93 65 .29 .14 Webster unpubl 1972 14 16 80 61 .18 .20 Webster unpubl 1973 12 7 67 .18 .10 Ramsay 1980 1974 20 9 75 .27 .12 Ramsay 1980 1975 10 10 80 .13 .13 Ramsay 1980 1976 16 8 84 .19 .10 Ramsay 1980 1977 10 15 62 .16 .24 Ramsay 1980 1978 27 17 58 .47 .29 Ramsay 1980 1979 19 29 56 .34 .52 Ramsay 1980 1980 17 18 53 .32 .34 Ramsay 1980 1982 23 17 81 38 .28 .21 Harper 1984 1983 20 19 82 44 .24 .23 Harper 1984 Average lamb:female (1970 to 1983) = 0.26 Average year ling-.female (1971 to 1983) = 0.22 6 I960 1965 1970 1975 1980 YEAR Figure 1. (A) Yearly maximum counts of females (2 years and older) on F l a t i r o n Mountain from 1960 to 1983. (B) Ratio of lambs per adult female from 1960 to 1983 based on ye a r l y maximum counts. See t a b l e 2 f o r a c t u a l values. 7 the Ashnola watershed s i n c e 1960 (Blood 1961, 1963, 1967; Sugden 1961; Demarchi 1965, 1968; Harper 1969; S i l v e r 1971; Morrison 1972; and S c h e f f l e r 1973). These s t u d i e s were mostly general e c o l o g i c a l i n v e s t i g a t i o n s of animal food h a b i t s and h a b i t a t c h a r a c t e r i s t i c s , and as such have provided l i m i t e d i n f o r m a t i o n a p p l i c a b l e to bighorn management. While there have been s e v e r a l i n v e s t i g a t i o n s of the Ashnola h a b i t a t , there has been no s a t i s f a c t o r y documentation of the r e p r o d u c t i v e , n u t r i t i o n a l , or d i s e a s e s t a t u s of these b i g h o r n . Ramsay (1980) s t u d i e d aspects of the r e p r o d u c t i v e b i o l o g y of Ashnola bighorn, and r e c o g n i s e d the importance of determining pregnancy r a t e as a method of i n v e s t i g a t i n g the cause of the low lamb r e c r u i t m e n t . He was, however, unable to capture female bighorn i n l a t e g e s t a t i o n to meet t h i s o b j e c t i v e . Previous work on v a r i o u s p o p u l a t i o n s of bighorn sheep has suggested three major p e r i o d s of bighorn lamb m o r t a l i t y . The f i r s t , neonatal m o r t a l i t y , occurs between b i r t h and a few days postpartum ( G e i s t 1971). A second p e r i o d of high lamb m o r t a l i t y occurs i n lambs one to four months o l d , a t t r i b u t a b l e to a lungworm/pneumonia complex (Woodard e t a_l. 1974; H o r e s j i 1976; Spraker and H i b l e r 1982). The t h i r d p e r i o d of high lamb m o r t a l i t y occurs d u r i n g the lambs' f i r s t winter (Blood 1961; Demarchi 1965; G e i s t 1971) . A f o u r t h p e r i o d , e a r l y p o s t n a t a l m o r t a l i t y , was c o n s i d e r e d i n t h i s study. E a r l y p o s t n a t a l m o r t a l i t y occurs a f t e r the neonatal p e r i o d but before the lambs reach one month of age. 8 Although m o r t a l i t y of lambs i n the F l a t i r o n herd between one month and one year of age was g r e a t e r than 25% f o r four years from 1960 to 1964 (Demarchi 1965) , c l a s s i f i c a t i o n counts s i n c e 1970 i n d i c a t e lamb m o r t a l i t y i n t h e i r f i r s t winter has not r e c e n t l y been t h a t high (Table 2) . A c c o r d i n g l y , t h i s study focussed on determining the number of bighorn o f f s p r i n g conceived and t h e i r s u r v i v a l d u r i n g the neonatal and e a r l y p o s t n a t a l p e r i o d s . Secondly, t h i s study focussed on e v a l u a t i n g from a v a i l a b l e data, the f a c t o r s a f f e c t i n g pregnancy r a t e and o f f s p r i n g s u r v i v a l . The number of o f f s p r i n g born depends on a s e r i e s of events beginning with o v u l a t i o n , and c o n t i n u i n g through f e r t i l i z a t i o n , cleavage and development to the b l a s t o c y s t stage, i m p l a n t a t i o n , p l a c e n t a t i o n , s u c c e s s f u l g e s t a t i o n , and p a r t u r i t i o n . A v a r i e t y of f a c t o r s a f f e c t each of these c r i t i c a l events and u l t i m a t e l y determine the e f f i c i e n c y of r e p r o d u c t i o n (Nalbandov 1976). Based on p r e v i o u s s t u d i e s of domestic sheep (Thomson and Thomson 1953; Munro 1962; Belschner 1965; Leathern 1966; Alexander and W i l l i a m s 1968; Butterworth and B l o r e 1969; Henne 1975; Nalbandov 1976; Webster 1976; Underwood 1977; H i d i r o g l o u 1980; Puis 1981; Dubeski 1983; Shamberger 1983), w i l d sheep (Ge i s t 1971; Shackleton 1973; H o r e s j i 1976; F a i r a i z l 1980; Bunnell 1982), and w i l d c e r v i d s (Verme 1965, 1977; Thorne e t a l . 1976; B l i x and Steen 1979; S t e i g e r s and F l i n d e r s 1980) , the process o f , and p o s s i b l e f a c t o r s 9 a f f e c t i n g , the p r o d u c t i o n and s u r v i v a l of lambs to one month of age are summarized i n F i g u r e 2. F i g u r e 2 i l l u s t r a t e s the p r o g r e s s i o n of the female through v a r i o u s p h y s i o l o g i c a l s t a t e s and events, d u r i n g the development of her o f f s p r i n g to 30 days postpartum, based on the format of a computer program f l o w c h a r t . No s u c c e s s f u l s t u d i e s of pregnancy r a t e s i n l i v i n g bighorn sheep had p r e v i o u s l y been accomplished, and the o n l y a v a i l a b l e data were f o r t u i t o u s and of l i m i t e d value f o r general a p p l i c a t i o n (e.g. S p a l d i n g 1966). Pregnancy r a t e d e t e r m i n a t i o n was the f i r s t sampling p o i n t d u r i n g the development of bighorn o f f s p r i n g t h a t was used to meet the f i r s t o b j e c t i v e , which was: 1. To i d e n t i f y the stage i n development when most o f f s p r i n g m o r t a l i t y i s o c c u r r i n g . As shown i n F i g u r e 2, there are a number of stages where p r o d u c t i o n f a i l u r e s can occur. However, a p i v o t a l p o i n t f o r a p r a c t i c a l study may be r e c o g n i z e d a c c o r d i n g to whether or not females are pregnant. I f pregnancy r a t e i s low then subsequent work must co n c e n t r a t e on those events and f a c t o r s p r i o r to g e s t a t i o n . A l t e r n a t i v e l y , i f pregnancy r a t e i s h i g h one can concentrate on l a t e prepartum and postpartum f a c t o r s . In order to meet o b j e c t i v e 1 concerning the timing of o f f s p r i n g l o s s e s the f o l l o w i n g n u l l r e s e a r c h hypothesis was t e s t e d : LEGEND /EVENT / / STATE/ DECISION. ENDPOINT Sources 1. Alexander and Williams 1968, 2. Belschner 1965. 3. Blix and Steen 1979. 4. Bunnell 1982. 5. Butterwarth and Blare 1969. 6. DubesJa 1983. 7. Fairaizl 1980. 8. Geist 1971. 9. Hart et aL 1961. 10. Henn 1973. 11. Hidiroglou 1980. 12. Haresji 1976. 13. Leathern 1966. 14. Munro 1962. 15. Nalbandov 1976. 16. Puis 1981. 17. Shacxleton 1973. 18. Shamberger 1983. 19. Steigers and Flinders 1980. 20. Thomson and Thomson 1953. 21. Thome et aL 1976. 22. Underwood 1977. 23. Verme 1965. 24. Verme 1977. 25. Webster 1976. -continued Figure 2 . Schematic diagram representing the process of, and factors affecting, production and survival of bighorn lambs to one month of age. 11 8 , 1 2 , 1 4 , 1 7 6 , 1 6 , 1 8 , 2 2 7 , 1 0 , 1 9 F i g u r e 2 . C o n t i n u e d . 12 Ho: There i s no d i f f e r e n c e between the pregnancy r a t e and lamb p r o d u c t i o n r a t e of F l a t i r o n Mt. females. Ha: The pregnancy r a t e i s higher than the p r o d u c t i o n r a t e . Data r e q u i r e d to t e s t t h i s hypothesis i s the pregnancy r a t e of the p o p u l a t i o n , based on a sample of captured females. A d d i t i o n a l data, r e q u i r e d to meet o b j e c t i v e 1, are the s u r v i v a l r a t e of lambs belonging to i n d i v i d u a l l y i d e n t i f i e d females, and the t i m i n g of any lamb m o r t a l i t i e s . Neonatal m o r t a l i t y i s d e f i n e d as o c c u r r i n g a t p a r t u r i t i o n or w i t h i n 2 days postpartum (Verme 1965,1977; G e i s t 1971; Lent 1974). E a r l y p o s t n a t a l m o r t a l i t y i s d e f i n e d as o c c u r r i n g a f t e r 2 days and before 30 days postpartum. To study the f a c t o r s i n v o l v e d i n the s u c c e s s f u l progress from g e s t a t i o n through p a r t u r i t i o n and l a c t a t i o n (Figure 2), the second o b j e c t i v e formulated was: 2. To i n v e s t i g a t e the n u t r i t i o n a l and d i s e a s e s t a t u s of females p r i o r to lambing and the e f f e c t s they have on the s u r v i v a l of o f f s p r i n g . S t u d i e s of domestic sheep have shown t h a t the female's body weight i s s i g n i f i c a n t l y a f f e c t e d by her n u t r i t i o n a l l e v e l (Peart 1968). Subsequently, ewe body weight has a s i g n i f i c a n t e f f e c t on lamb b i r t h weight (Butterworth and B l o r e 1969; Peart et a l . 13 1975) which may a f f e c t lamb s u r v i v a l (Thomson and Thomson 1953)(see F i g u r e 2 ) . Smith (1970) reviewed methods f o r e s t i m a t i n g p h y s i c a l c o n d i t i o n i n ungulates, and concluded the kidney f a t index was the most u s e f u l i n terms of accuracy and f i e l d a p p l i c a b i l i t y . In w h i t e - t a i l e d deer (Odocoileus v i r g i n i a n u s ) the 2 kidney f a t index has been shown to a c c u r a t e l y p r e d i c t (r =0.75) the percent t o t a l body f a t (Finger e t a_l. 1981) . Other techniques f o r measuring n u t r i t i o n a l s t a t u s u s u a l l y i n v o l v e e s t i m a t i n g the amount of d e p o s i t e d f a t r e s e r v e s , although Bandy et a_l. (1956) suggested a technique based on the r e l a t i o n s h i p between body weight, c h e s t g i r t h , and h i n d f o o t l e n g t h . The d i f f i c u l t y with kidney f a t i n d i c e s and most other d i r e c t measures of f a t r e s e r v e s i s t h a t they i n v o l v e measuring dead animals, and thus are not f e a s i b l e f o r small threatened p o p u l a t i o n s . C o n s i d e r i n g the l i m i t a t i o n s of working with l i v e animals, the three most f e a s i b l e techniques f o r determining n u t r i t i o n a l s t a t u s i n l i v i n g bighorn sheep are body s i z e (Bandy e t a l . 1956) , subcutaneous f a t r e s e r v e s (Russel e t a_l. 1969) , and blood chemistry (Franzmann and Thorne 1970; Hebert 1978; Peterson and B o t t r e l l 1978). N u t r i t i o n through the l a s t t h i r d of g e s t a t i o n has a d i r e c t e f f e c t on domestic lamb b i r t h weights; f o r example an average 4.3 kg b i r t h w e i g h t r e s u l t s when feed i s adjusted to minimize c a t a b o l i s m of f a t s t o r e s , versus 3.0 kg when blood f r e e f a t t y a c i d s and ketones i n d i c a t e adipose t i s s u e s are being m o b i l i z e d (Peart 1967). S i m i l a r f i n d i n g s have been rep o r t e d by 14 other r e s e a r c h e r s i n domestic sheep (Wallace 1948; Russel e t a l . 1967; Butterworth and B l o r e 1969), and w i l d c e r v i d s (Verme 1965, 1969; Thome e t a l . 1976). C e r t a i n i n f e c t i o u s d i s e a s e s , of both v i r a l and b a c t e r i a l o r i g i n , can cause s t e r i l i t y and impaired f e r t i l i t y i n a v a r i e t y of ungulates (Belschner 1965; Nalbandov 1976). Disease s t a t u s i n l i v i n g b ighorn can be assessed by n a s a l swab (Parks e t a l . 1972; Ma r s h a l l e t a l . 1983) and serum antibody t i t r e (Parks and England 1974; Turner and Payson 1982). In order to meet o b j e c t i v e 2, the n u t r i t i o n a l s t a t u s of females from F l a t i r o n Mt. can be compared t o a c a p t i v e r e s e a r c h herd a t the Okanagan Game Farm i n terms of body c o n d i t i o n and l i v e w e i g h t . O b j e c t i v e 2 can a l s o be addressed by comparing d i f f e r e n c e s i n weight, body c o n d i t i o n s core, blood m i n e r a l s , and d i s e a s e a f f l i c t i o n among females on F l a t i r o n Mt. to the s u r v i v a l of t h e i r o f f s p r i n g . Thus, any d i f f e r e n c e s i n the n u t r i t i o n a l or di s e a s e s t a t u s between those females t h a t produce v i a b l e lambs, and those t h a t l o s e t h e i r lambs, should become apparent. The t h i r d o b j e c t i v e of the study r e l a t e d to the i n f l u e n c e of weather on the s u r v i v a l of lambs, s i n c e newborn ungulates are s e n s i t i v e to thermoregulatory s t r e s s ( B l i x and Steen 1979). 15 3. To document the s e v e r i t y of weather d u r i n g the lambing p e r i o d r e l a t i v e to the s u r v i v a l of bighorn lambs. Lambs which are s u b j e c t to n u t r i t i o n a l s t r e s s d u r i n g g e s t a t i o n w i l l have lower b i r t h weights, mineral d e f i c i e n c i e s , or both, and thus are more susceptable to acute c o l d s t r e s s a f t e r they are born (Figure 2) . L i k e w i s e , lambs t h a t do not r e c e i v e adequate milk s u p p l i e s a f t e r they are born w i l l be more susceptable t o hypothermia. However, severe inclement weather i n the presence of adequate n u t r i t i o n c o u l d c o n c e i v a b l y cause m o r t a l i t y d i r e c t l y , i f the energy d r a i n were severe enough to exceed the lambs' summit metabolism. In order to avoid a negative energy balance, a 5 kg domestic _ 2 lamb must e l e v a t e i t s metabolism to 350 W.m a t -10 C i n a 5.5 m/s wind; however, summit metabolism of a 5 kg domestic lamb i s -2 on l y 360 W.m (Webster 1976). The lower c r i t i c a l temperature i n s t i l l a i r of a d u l t bighorn i n winter pelage i s -20 C (Chappel and Hudson 1978). The lower c r i t i c a l temperature of newborn domestic lambs i n s t i l l a i r i s much h i g h e r , ranging from +22 to +32 C when wet, and +12 to +22 C when dry (Webster 1976) . I t i s apparent t h a t although bighorn lambs are probably b e t t e r adapted to c o l d than are domestic lambs, temperatures encountered d u r i n g the lambing p e r i o d on F l a t i r o n Mountain could r e s u l t i n an energy c o s t f o r t h e r m o r e g u l a t i o n . For example, i n c a r i b o u c a l v e s (Rangifer tarandus) the r e s t i n g metabolic r a t e was doubled at 0 C i n s t i l l a i r , and • e l e v a t e d to f i v e times r e s t i n g r a t e when 16 inclement weather was s u f f i c i e n t t o cause hypothermia and death (Hart e t a l . 1961). The i n c r e a s e d metabolic demand r e q u i r e d t o maintain body temperature d u r i n g inclement weather i s met by two homeostatic feedback systems. The autonomic system i n v o l v e s c a t a b o l i s i n g brown adipose t i s s u e r e s e r v e s . However, these brown f a t energy r e s e r v e s , with which the neonate i s born, are e a s i l y exhausted i f the lamb does not s u c k l e soon a f t e r b i r t h (Alexander 1962). At b i r t h , brown adipose t i s s u e accounts f o r 40% of the heat generated a t summit metabolism, but only 5% a t 30 days postpartum (Alexander and W i l l i a m s 1968). The other thermoregulatory system i n young lambs i n v o l v e s the somatic s h i v e r i n g response. At summit metabolism t h i s accounts f o r 60 and 95% of the heat generated i n newborn and 30 day o l d domestic lambs r e s p e c t i v e l y (Alexander and W i l l i a m s 1968) . Data r e q u i r e d to meet o b j e c t i v e 3 are the d a i l y minimum and maximum temperatures, humidity, and p r e c i p i t a t i o n on the South Slope lambing grounds d u r i n g the lambing p e r i o d . These data can then be compared to counts of lambs d u r i n g the lambing p e r i o d to determine i f inclement weather d u r i n g the lambing p e r i o d i s a s s o c i a t e d w i t h an i n c r e a s e i n the m o r t a l i t y of lambs. Whereas n u t r i t i o n through g e s t a t i o n has been determined to have a s i g n i f i c a n t e f f e c t on the b i r t h weight of domestic lambs, i t has marginal e f f e c t on subsequent milk p r o d u c t i o n (Barnicoat 17 e t a l . 1949, 1957; Peart 1967; Butterworth and B l o r e 1969), p r o v i d i n g energy and p r o t e i n i n t a k e d u r i n g l a c t a t i o n i s adequate (Butterworth e t a l . 1968; Peart 1968; Forbes 1969). The e n e r g e t i c requirement of l a c t a t i o n i n domestic sheep i s two and one h a l f times t h a t of maintenance, and exceeds the c o s t of f e t a l p r o d u c t i o n (NRC 1975). As such, i t would be expected t h a t a p r o t e i n / e n e r g y d e f i c i e n c y i n Ashnola females would manifest i t s e l f i n a lower milk p r o d u c t i o n . In domestic sheep 71% of the d a i l y weight g a i n of lambs i s d i r e c t l y dependent on the milk y i e l d of t h e i r dams (mean c o e f f i c i e n t of d e t e r m i n a t i o n of e i g h t s t u d i e s : Wallace 1948; B a r n i c o a t e t a l . 1949, 1957; Owen 1957; Munro 1962; Butterworth e t aL. 1968; Forbes 1969; Peart et a l . 1975). Work with bighorn sheep has found d i f f e r e n c e s i n the d u r a t i o n of the s u c k l i n g bout between s p e c i e s (G e i s t 1971), between p o p u l a t i o n s (Shackleton 1973), and between years i n the same p o p u l a t i o n ( H o r e s j i 1976). These d i f f e r e n c e s were r e l a t e d to lamb p r o d u c t i o n and p o p u l a t i o n q u a l i t y ( G e i s t 1971). The f o u r t h o b j e c t i v e was to. determine i f l a c t a t i o n p r o d u c t i o n was s u f f i c i e n t l y low to be l i m i t i n g the s u r v i v a l of lambs. 4. To assess the l a c t a t i o n p r o d u c t i o n of females i n the f i r s t month a f t e r p a r t u r i t i o n r e l a t i v e to p o p u l a t i o n s w i t h known lamb p r o d u c t i o n . 18 Data r e q u i r e d to meet o b j e c t i v e 4 are the d u r a t i o n and frequency of s u c k l i n g bouts of F l a t i r o n Mt. lambs of d i f f e r e n t ages, under the assumption t h a t these v a r i a b l e s are i n d i c a t i v e of milk p r o d u c t i o n (Shackleton 1973). These data can then be compared to other s t u d i e s to determine i f F l a t i r o n Mt. lambs r e c e i v e r e l a t i v e l y l e s s milk than p o p u l a t i o n s t h a t have higher lamb p r o d u c t i o n . P r e d a t i o n i s the t h i r d main f a c t o r which may a f f e c t the s u r v i v a l of bighorn lambs i n the f i r s t f our weeks a f t e r p a r t u r i t i o n (Figure 2). However, while p r e d a t i o n may a c t independantly of the other two f a c t o r s , lambs which had been s u b j e c t to n u t r i t i o n a l s t r e s s d u r i n g g e s t a t i o n or l a c t a t i o n would be much more s u s c e p t i b l e to predator a t t a c k s . Likewise severe inclement weather c o u l d weaken lambs and make them e a s i e r prey. There are s e v e r a l p o t e n t i a l p redators of bighorn sheep i n the Ashnola watershed. Three members of the f a m i l y F e l i d a e i n h a b i t the area, the cougar ( F e l i s c o n c o l o r ) , the lynx (Lynx  l y n x ) , and the bobcat ( F e l i s r u f u s ) . A l l three are known to prey on young ungulates, with the cougar being the l a r g e s t at approximately 46 kg, f o l l o w e d by the bobcat a t 16 kg, and the lynx a t 8 kg (Cowan and Guiguet 1956). Two members of the f a m i l y Canidae occur i n the study area. The coyote (Canis l a t r a n s ) i s the l a r g e s t a t 13 kg and i s a l s o the most abundant based on t r a c k s and o b s e r v a t i o n s . The red fox 19 (Vulpes vulpes) i s much s m a l l e r a t 5 kg (Cowan and Guiguet 1956) and i s probably present i n lower d e n s i t i e s . Black bears (Ursus americanus) and golden eagles ( A q u i l a  chrysaetos) are a l s o r e l a t i v e l y abundant i n the study area and can be c o n s i d e r e d to be p o t e n t i a l p r e d a t o r s . The f i f t h o b j e c t i v e of the study was: 5. To determine i f bighorn sheep c o n s t i t u t e a major component (25% or g r e a t e r ) of the d i e t of predators d u r i n g the lambing p e r i o d . Data which can be obtained to meet o b j e c t i v e 5 are o b s e r v a t i o n s of i n t e r a c t i o n between lambs and p r e d a t o r s , and the p r o p o r t i o n of bighorn remains which occur i n p r e d a t o r s s c a t s . 20 STUDY AREA The focus of t h i s study was the p o p u l a t i o n of bighorn i n h a b i t i n g F l a t i r o n Mountain i n the Ashnola watershed, t o t a l l i n g approximately 165 to 175 animals (Figure 3 ) . F i e l d work conducted between A p r i l 1982 and August 1983 concentrated on F l a t i r o n Mountain, because i t s unique topographic c h a r a c t e r i s t i c s allowed a l l age-sex c l a s s e s of bighorn t o be e a s i l y observed. For comparative purposes a d d i t i o n a l data on the pregnancy s t a t u s , weights, and c o n d i t i o n of females were c o l l e c t e d from; 1) a c a p t i v e p o p u l a t i o n of r e s e a r c h bighorn on n a t i v e range a t the Okanagan Game Farm, and 2) a f r e e ranging p o p u l a t i o n t h a t w inters eas t of Vaseux Lake i n the Okanagan V a l l e y . O c c u r r i n g i n a t r a n s i t i o n zone between the Cascade Mountains to the south, and the Thompson P l a t e a u t o the n o r t h , the Ashnola watershed c o n s i s t s of a h i g h l y d i s s e c t e d p l a t e a u , v a r y i n g i n e l e v a t i o n from approximately 1500 to 2100 m above sea l e v e l (Figure 3 ) . The Ashnola experiences a rainshadow e f f e c t common to the southern i n t e r i o r of B r i t i s h Columbia, and thus the low p r e c i p i t a t i o n r e s u l t s i n development of s e m i - a r i d , grass steppe p l a n t communities. The south s i d e of F l a t i r o n Mountain (South Slope) and i t s env i r o n s was where o b s e r v a t i o n s of tagged and untagged females were made (Figure 3 ) . South Slope (400 ha) i s f r e q u e n t l y used by Figure 3. The study area on F l a t i r o n Mountain i n the Ashnola River watershed. 22 sheep, and c o n s i s t s of a mixture of continuous grass steppe communities r i s i n g from an e l e v a t i o n of 1000 m t o 2100 m a t the top of F l a t i r o n Mountain (Figure 3), while J u n i p e r Slope (100 ha) r i s e s from 1700 to 2000 m e l e v a t i o n and i s l i t t l e used by b i g h o r n . To the west of South Slope and J u n i p e r Slope a rugged c l i f f t e r r a i n of small p l a t e a u s and ledges i s used by some females f o r lambing. C l i f f s Ridge (50 ha) to the e a s t of South Slope i s a steep south f a c i n g slope frequented mainly by rams. Together, these make up most of the w i n t e r - s p r i n g h a b i t a t of the F l a t i r o n Mountain p o p u l a t i o n of b i g h o r n . D e t a i l e d d e s c r i p t i o n s of the topography and b o t a n i c a l composition of the grass steppe communities of the Ashnola watershed are a v a i l a b l e elsewhere (Blood 1961; Demarchi 1965; Harper 1969; S c h e f f l e r 1972; Harcombe and Kowall 1982). V a s c u l a r p l a n t neomenclature i s a f t e r T a y l o r and MacBryde (1977) . The grass steppe, bighorn h a b i t a t occurs i n s e v e r a l l a r g e (50 to 400 ha) i s l a n d s surrounded by climax D o u g l a s - f i r (Pseudotsuga  m e n z i e s i i ) parkland and f i r e s u c c e s s i o n a l lodgepole pine (Pinus  c o n t o r t a ) communities between 1000 and 2300 m e l e v a t i o n . The grass steppe i s a mixture of s e v e r a l community types, with Agropyron spicatum - K o e l a r i a macrantha type being the most common due to x e r i c c o n d i t i o n s on the steep s o u t h - f a c i n g slopes (Harper 1969). Mesic s o i l moistures occur i n areas of l e s s s lope, and Agropyron spicatum - Festuca i d a h o e n s i s communities predominate. Forage p r o d u c t i o n on these f i r s t two communities 23 v a r i e s between 500 and 1200 kg.ha , depending p r i m a r i l y on s o i l moisture v a r i a t i o n s due to slope (Demarchi 1965; Harper 1969). In h y g r i c areas with l i t t l e or no slope a p r o d u c t i v e community (up to 2000 kg.ha - 1) occurs where Poa p r a t e n s i s i s the dominant grass s p e c i e s (Harper 1969; S c h e f f l e r 1973). 24 METHODS Capture and Data C o l l e c t i o n A t o t a l of 12 bighorn females were captured d u r i n g February and March, 1983, i n a t r a p l o c a t e d a t 1400 m e l e v a t i o n on the west end of South Slope (Figure 3) . The p o p u l a t i o n has been fed winte r supplements i n the form of a p e l l e t e d r a t i o n s i n c e 1977, and t h i s was used as b a i t f o r the t r a p p i n g program. Minimal amounts of b a i t were used to av o i d confounding the n u t r i t i o n a l s t a t u s of the p o p u l a t i o n . A c o r r a l - t y p e t r a p was c o n s t r u c t e d 3 to 4 m high and 25 m i n diameter from mesh f i s h i n g net covered with b u r l a p t o form a v i s u a l b a r r i e r . A gate 3 m high and 5 m wide was r e l e a s e d , e i t h e r manually, or e l e c t r i c a l l y , when bighorn were i n s i d e the c o r r a l . Once captured, the sheep were q u i e t l y d r i v e n i n t o a corner chute which l e d to two plywood h a n d l i n g c r a t e s . The f a r end of the h a n d l i n g c r a t e s was covered i n n e t t i n g so there was no v i s u a l b a r r i e r . When the sheep were i n the c r a t e s , plywood doors at the ends were c l o s e d . Based on experience with the Okanagan Game Farm r e s e a r c h p o p u l a t i o n , the sheep were l e f t a t l e a s t 1 h before h a n d l i n g . The l a s t f i v e sheep captured on two d i f f e r e n t o c c a s i o n s were a l s o given a low dose (<lmg.kg ^) of x y l a z i n e (manufactured by Rogar/STB under the l a b e l Rompun) as a se d a t i v e 25 to f a c i l i t a t e h a n d l i n g and reduce s t r e s s . Pregnancy Diagnosis Pregnancy s t a t u s was diagnosed, based on the presence or absence of f e t a l and maternal t i s s u e s of pregnancy, by u l t r a s o n i c scanning u s i n g a Doppler Ultrasound Pregnancy Detector (Medata Systems L t d . , The Parade, Pagham, West Sussex, England, P021 4WT) . Doppler u l t r a s o u n d has been used a c c u r a t e l y to d e t e c t pregnancy i n domestic sheep by s e v e r a l authors (Lindahl 1971; Hulet 19 73; Deas 1977; Wani and Sahni 1981; Trapp and S l y t e r 1983) . The technique i s a l s o e f f e c t i v e f o r bighorn sheep, and i n a p r e l i m i n a r y t e s t of the technique with the c a p t i v e r e s e a r c h p o p u l a t i o n a t the Okanagan Game Farm, the accuracy was 100% (Harper and Cohen, i n press) . T h i s i s the f i r s t time t h a t u l t r a s o u n d has been used to determine pregnancy r a t e s i n f r e e ranging bighorn sheep. S p e c i f i c d e t a i l s of t h i s technique are given i n Appendix 1. Blood and T i s s s u e Samples To determine t r a c e mineral s t a t u s of i n d i v i d u a l sheep, s i x blood samples were obtained by j u g u l a r venipuncture using 20 gauge needles and 15 ml v a c u t a i n e r s . Once the blood had c o a g u l a t e d , serum was separated by c e n t r i f u g a t i o n , or when not p o s s i b l e , by l e t t i n g the blood stand o v e r n i g h t . The serum samples were then kept on i c e u n t i l they c o u l d be f r o z e n (within 26 5 d a y s ) , and submitted to the V e t e r i n a r y Pathology Laboratory at Abbotsford, B.C. f o r t r a c e element a n a l y s i s and d i s e a s e antibody t i t r e s . A t o t a l of 25 l i v e r and 17 kidney samples were obtained from hunter-harvested rams, road k i l l e d ewes and lambs, and one t r a p p i n g m o r t a l i t y . Samples were submitted to the V e t e r i n a r y Pathology Laboratory, Abbotsford, f o r d e t e r m i n a t i o n of i r o n , selenium, z i n c , copper, and manganese c o n c e n t r a t i o n s . A e r o b i c B a c t e r i a and V i r u s Sampling Nasal swabs were i n s e r t e d 15 cm i n t o the e x t e r n a l nares and r o t a t e d to c o l l e c t samples f o r c u l t u r e . A f t e r e x t r a c t i o n the swabs were immediately p l a c e d i n s t e r i l e f i x a t i v e and kept c o o l u n t i l submitted to the P r o v i n c i a l V e t e r i n a r y Pathology Laboratory at Abbotsford, B.C.. C u l t u r e t t e s (manufactured by Canlab), a s t e r i l e c u l t u r e c o l l e c t i o n system c o n t a i n i n g 0.5 ml of modified S t u a r t ' s b a c t e r i a l t r a n s p o r t medium, were used to c o l l e c t b a c t e r i a l samples. For v i r a l samples the V i r o c u l t c o l l e c t i o n system was used (Medical Wire and Equipment Co. L t d . ) . Weights and Measurements and Body C o n d i t i o n Scores Liveweight was determined with a d i a l s p r i n g s c a l e , accurate to 0.5 kg, with the animals h e l d i n a small plywood box. Body measurements t o , 1.0 mm, taken w i t h a f l e x i b l e s t e e l tape, i n c l u d e d : hind f o o t l e n g t h , t o t a l body l e n g t h , chest g i r t h , 27 (Bandy e t a_l. 1956; Blood e t a_l. 1970). The l e v e l of f a t d e p o s i t i o n i n bighorn females was estimated by a m o d i f i c a t i o n of Body C o n d i t i o n S c o r i n g (Russel e t a l . 1969); a common technique used i n domestic sheep r e s e a r c h . T h i s provided a way of s t a n d a r d i z i n g a s u b j e c t i v e assessment of f a t n e s s i n l i v e animals based on c e r t a i n p h y s i c a l c h a r a c t e r i s t i c s , which vary a c c o r d i n g to the l e v e l of f a t d e p o s i t i o n i n the lumbar r e g i o n . A Body C o n d i t i o n Score, ranging from 0 t o 5, was assigned to each female based on a d e s c r i p t i v e s c a l e (Appendix 2) . A l l the animals examined by t h i s technique f e l l i n t o one of three broad c a t e g o r i e s , score 1, score 2 and score 3. Some animals d i d not f i t e x a c t l y to the scores d e s c r i b e d i n Appendix 2 and were t h e r e f o r e g i v e n i n t e r m e d i a t e v a l u e s . I d e n t i f i c a t i o n C o l l a r s and Eartags Before being r e l e a s e d , the a d u l t females were f i t t e d with a permanent, nylon, i d e n t i f i c a t i o n c o l l a r (n=10). F i v e animals, i n c l u d i n g a lamb, were gi v e n i n d i v i d u a l p l a s t i c eartags (Duflex, manufactured by F e a r i n g ) . Observation and Census of the P o p u l a t i o n Census Technique A s t a n d a r d i z e d t r a n s e c t , developed by B.C. M i n i s t r y of Environment personnel and employed d u r i n g a previous study of the p o p u l a t i o n (Ramsay 1980) , was the most f r e q u e n t l y used route f o r 28 c l a s s i f i c a t i o n counts of the p o p u l a t i o n (Figure 3). Other t r a n s e c t s used d u r i n g f i e l d o b s e r v a t i o n s were designed to maximize the number of d i f f e r e n t bighorn observed. Only those c l a s s i f i c a t i o n counts i n which a l l of South Slope and Juni p e r Slope were thoroughly scanned are i n c l u d e d i n estimates of the t o t a l s i z e and age-sex composition of the p o p u l a t i o n . I f there was any p o s s i b i l i t y t h a t the same animal was counted twice, the census was repeated or the data d i s c a r d e d . Age-sex c l a s s e s and marked i n d i v i d u a l s were i d e n t i f i e d u s i n g 7X50 b i n o c u l a r s and a s p o t t i n g scope with 20X or 40X ey e p i e c e s . Bighorn were c l a s s i f i e d as lambs ( l e s s than 1 year o l d ) , male' and female y e a r l i n g s (1 to 2 years o l d ) , a d u l t females and a d u l t males (greater than 2 years o l d ) . The a d u l t males were a d d i t i o n a l l y c l a s s i f i e d i n t o one of fo u r age c l a s s e s based on horn s i z e ( G e i s t 1971). S u c k l i n g Behaviour S u c k l i n g behaviour of lambs of both tagged and untagged females was q u a n t i f i e d as an i n d i r e c t estimate of l a c t a t i o n p r o d u c t i o n . Observations of s u c k l i n g i n c l u d e d data on the d u r a t i o n o f the s u c k l i n g bout, the number of bunts d u r i n g the s u c k l i n g bout, and the frequency of n u r s i n g when known i n d i v i d u a l s were observed c o n t i n u o u s l y f o r two or more c o n s e c u t i v e bouts. Suckle d u r a t i o n s t o the ne a r e s t 0.1 s were timed u s i n g a stopwatch, and the terminator of the bout was 29 r e c o r d e d . Since lambing occurred over a p e r i o d of approximately one month, lambs of many d i f f e r e n t ages were present i n the nursery groups a t any one time. To q u a n t i f y the age of the lamb the he i g h t of i t s back r e l a t i v e to the b e l l y of i t s dam was recorded along with the b e h a v i o u r a l i n f o r m a t i o n . By ob s e r v i n g f i v e marked females of known p a r t u r i t i o n dates, the s i z e of lambs r e l a t i v e to t h e i r dams was c o r r e l a t e d to age, and assuming an equal growth r a t e f o r a l l lambs, the r e l a t i o n s h i p was used to age lambs of unmarked females. Lambs were c l a s s i f i e d i n t o t hree c a t e g o r i e s ( l e s s than b e l l y h e i g h t , equal to b e l l y h e i g h t , and g r e a t e r than b e l l y h e i g h t ) , which corresponded to three age groups r e s p e c t i v e l y : 2 to 10 days, 11 to 25 days, and 26 to 50 days. C l i m a t o l o g i c a l S t a t i o n s The temperature, humidity, and p r e c i p i t a t i o n were monitored u s i n g two ground l e v e l thermographs l o c a t e d a t d i f f e r e n t e l e v a t i o n s , and one hygrothermograph i n a Stevenson Screen l o c a t e d 1.5 m above the ground (Figure 3 ) . The lower (1065 m e l e v a t i o n ) ground l e v e l thermograph (TI) was l o c a t e d on a ledge i n the South Slope lambing grounds shaded by a rock and white plywood sheet. The upper (1585 m e l e v a t i o n ) ground l e v e l thermograph (T2) was l o c a t e d i n the shade of the r e s e a r c h c a b i n , l e s s than 100 m from the top of the South Slope lambing grounds. The hygrothermograph i n a Stevenson Screen (HT3) was a l s o at 1585 30 m e l e v a t i o n and was l e s s than 200 m from the South Slope lambing grounds. R e l a t i v e humidity on the hygrothermograph (HT3) was c o r r e c t e d u s i n g a s l i n g psychrometer. Two storage raingauges were l o c a t e d a t .the HT3 s t a t i o n . Predator Food Habits To determine i f bigh o r n lambs were a s i g n i f i c a n t component of the e a r l y s p r i n g d i e t of p r e d a t o r s , 81 s c a t s were c o l l e c t e d from A p r i l 20 to June 20, i n 1982 and 1983. E f f o r t s were made to c o l l e c t o n l y f r e s h s c a t s , but s i n c e the c o l l e c t i o n s were done i n e a r l y s p r i n g , some s c a t s may have been d e p o s i t e d i n the previous winter and may have j u s t r e c e n t l y thawed. Most c o l l e c t i o n s were made on t r a i l s which were f r e q u e n t l y c l e a r e d of a l l predator s c a t s , so the approximate age of most s c a t s was t h e r e f o r e known. The s c a t s were s t e r i l i z e d a g a i n s t Echinococcus granulosus by d r y i n g i n an oven a t 110° C f o r 8 h, and then were washed over 1 mm and 0.5 mm s i e v e s to remove a l l m a t e r i a l except f o r h a i r , bone, and i n s e c t e x o s k e l e t o n . I d e n t i f i c a t i o n of prey s p e c i e s was accomplished, u s i n g a 50X and 100X l i g h t microscope, from the c h a r a c t e r i s t i c s c a l e p a t t e r n s on guard h a i r s (Adorjan and Kolenosky 1969; Moore et al. 1974). Bighorn lamb h a i r was d i s t i n g u i s h e d from a d u l t h a i r when diameters of the guard h a i r s h a f t s were l e s s than 130 u. 31 S t a t i s t i c a l A n a l y s i s A l l means are giv e n +/- the standard d e v i a t i o n . Two-tailed Student's t - t e s t s f o r samples of unequal s i z e and v a r i a n c e were used to d e t e c t d i f f e r e n c e s between group means f o r lamb s u c k l i n g bout r a t e and temperatures a t two d i f f e r e n t e l e v a t i o n s on the South Slope lambing grounds. Chi-square a n a l y s i s of body c o n d i t i o n scores was used to .determine i f the ranked scores came from the same s t a t i s t i c a l p o p u l a t i o n . The 5% l e v e l of p r o b a b i l i t y was s e l e c t e d a p r i o r i f o r t e s t s of hypotheses. One-way A n a l y s i s of Va r i a n c e was used to determine the e f f e c t of p o p u l a t i o n on the l i v e w e i g h t of a d u l t females sampled at the same time of the year. Data on the s u c k l i n g behaviour of lambs were a l s o analysed by one-way ANOVA to determine the e f f e c t of age on both the d u r a t i o n of the s u c k l i n g bout and the r a t e of bun t i n g . The d i s t r i b u t i o n of suc k l e d u r a t i o n s was skewed, t h e r e f o r e a n a t u r a l l o g t r a n s f o r m a t i o n was used t o normalize these d a t a . One-way ANOVA was accomplished u s i n g the BMD:10V s t a t i s t i c a l package (UCLA Medical School, Los Angeles, C a l i f o r n i a ) . The f o l l o w i n g l i n e a r model was used: Y.. = ju + A. + E . , . > 13 1 3 d ) 1 32 where, Y^j . = s u c k l i n g bout d u r a t i o n , or bunt r a t e , or l i v e w e i g h t . ju = o v e r a l l mean. = e f f e c t of lamb age, or p o p u l a t i o n (3 l e v e l s ) . E . . .. = e r r o r term. 3 U) S i g n i f i c a n t d i f f e r e n c e s among means were determined u s i n g Duncan's M u l t i p l e Range t e s t with the a p r i o r i p r o b a b i l i t y l e v e l s e t a t 5%. 33 RESULTS Timing of O f f s p r i n g Losses Pregnancy Rate A l l 10 a d u l t females captured l i v e on F l a t i r o n Mountain between January 29 and March 24, 1983, were diagnosed pregnant by Doppler u l t r a s o u n d . The one capture m o r t a l i t y was a l s o pregnant with a s i n g l e f e t u s . Thus, f o r the sample of bighorn 4.5 years and o l d e r , the pregnancy r a t e was 100% (Table 3 ) . Based on a g e s t a t i o n p e r i o d f o r (CX c a l i f o r n i a n a ) of 174.2 +/- 1.7 days (Shackleton e t a_l. 19 84) , and the estimated dates of p a r t u r i t i o n f o r each female, the mean f e t a l age a t the time of d i a g n o s i s was 105.8 +/- 18.5 days (range 73 to 130 days, Table 3 ) . Serum progesterone c o n c e n t r a t i o n s of four a d u l t females diagnosed pregnant by u l t r a s o u n d averaged 15.3 +/- 7.8 n g . m l - 1 , while t h a t of the female lamb was 0.2 ng.ml 1 (Table 4 ) . S u r v i v a l of Lambs from Tagged Females Of the t o t a l estimated p o p u l a t i o n of 82 a d u l t females, 10 tagged females and one n a t u r a l l y marked female could be i n d i v i d u a l l y i d e n t i f i e d and observed through the lambing p e r i o d . The p a t t e r n of i s o l a t i o n showed f i v e of them (Category I) gave b i r t h on the c l i f f escape t e r r a i n a t the west end of South Slope T a b l e 3 . P r e g n a n c y d i a g n o s i s , w e i g h t s , a n d m e a s u r e m e n t s o f b i g h o r n f e m a l e s c a p t u r e d o n F l a t i r o n M o u n t a i n i n 1 9 8 3 . F E T A L B A S I S O F D I A G N O S I S " W E I G H T B O D Y T O T A L H I N D F O O T A G E D A T E O F A G E ( D o p p l e r u l t r a s o u n d ) C O N D . L E N G T H L E N G T H I . D . y e a r s D I A G N O S I S d a y s F H R F M P C U A k g S C O R E mm m m 0 1 0 . 5 n / a 2 5 . 5 1 . 5 0 1 2 8 0 _ 0 2 4 . 5 0 7 / 0 3 1 2 8 b 1 3 2 + + 5 6 . 7 1 . 7 5 1 6 5 0 3 8 0 0 3 6 . 5 2 1 / 0 2 1 0 2 c 1 6 8 + + . 5 8 . 0 2 . 0 0 1 5 6 0 3 6 4 0 4 6 . 5 0 6 / 0 3 1 2 2 c + + 5 9 . 4 3 . 0 0 - 3 8 5 0 5 6 . 5 2 1 / 0 2 9 5 - 1 0 5 d ( a u t o p s y ) 6 4 . 9 3 . 0 0 1 5 7 0 4 0 5 0 6 7 . 5 0 7 / 0 3 I 1 9 c 1 2 6 + + + 5 7 . 6 2 . 0 0 1 4 7 0 4 1 0 0 7 7 . 5 + 0 6 / 0 2 8 7 ' + 6 7 . 1 2 . 5 0 1 6 7 0 4 2 0 0 8 7 . 5 + 2 9 / 0 1 8 6 b + 6 8 . 0 3 . 0 0 - 4 0 0 0 9 . 8 . 5 + 0 6 / 0 2 7 3 b + + 5 9 . 0 2 . 0 0 1 6 3 0 3 7 5 1 0 8 . 5 + 2 4 / 0 3 1 3 0 e 1 0 8 + + + 6 4 . 4 1 . 7 5 1 6 2 0 4 0 0 1 1 9 . 5 + 0 7 / 0 3 1 0 5 e u + 6 1 . 2 1 . 7 5 1 6 0 0 3 9 5 1 2 9 . 5 + 2 6 / 0 2 1 1 2 b 1 6 2 + + — 2 . 5 0 1 7 0 0 3 9 0 a - F H R = f e t a l h e a r t r a t e ( b p m ) ; F M = f e t a l m o v e m e n t ; P C = p l a c e n t a l c i r c u l a t i o n ; U A = u t e r i n e a r t e r y , b - F e t a l a g e e s t i m a t e d f r o m o b s e r v a t i o n s o f n e w b o r n l a m b s , c - F e t a l a g e e s t i m a t e d f r o m d a t e s w h e n f e m a l e s i s o l a t e d t h e m s e l v e s , d - F e t a l a g e e s t i m a t e d f r o m t h e m e a n b i r t h d a t e o f t h e p o p u l a t i o n . Table 4. Blood chemistry of female bighorn from F l a t i r o n Mountain. C o n c e n t r a t i o n i n Blood Serum Serum A d u l t females Lamb female C o n s t i t u e n t U n i t s x SD n n=l Trace elements-Selenium , -1 mg .kg .090 .034 5 .046 Copper mg.kg .69 .08 4 .35 Zinc , -1 mg.kg .52 .19 4 .25 Iodine ( t o t a l ) mcg% 5.3 1.3 4 5.0 Macro elements Calcium mg% 8.95 .41 4 9.7 Magnesium mg% 1.95 .57 4 1.28 Phosphorus mg% 3.25 .73 4 5.9 Reproductive hormone-Progesterone ,-1 ng.ml 15.3 7.8 4 0.2 36 (Figure 3) , and f i v e of them (Category II) gave b i r t h at an undetermined l o c a t i o n . Although female #10 had been diagnosed pregnant, she was c o n s i s t a n t l y observed on South Slope, but never with a lamb of her own. Since i t c o u l d not be determined i f and when she i s o l a t e d h e r s e l f , she was placed i n n e i t h e r category. Of the f i v e females i n Category I observed on the South Slope lambing grounds, o n l y two (#2 and #12) had lambs which s u r v i v e d u n t i l e a r l y August (Figure 4) . The other three females i n Category I were observed with lambs, but they l o s t them when the lambs were between 5 and 21 days o l d . The females i n Category II l e f t South Slope f o r p e r i o d s ranging from approximately 16 to 60 days. There was c o n s i d e r a b l e v a r i a t i o n i n the date they l e f t and i n the time they spent away from the main w i n t e r - s p r i n g range. As with the females which remained on and near South Slope, o n l y 2 of the 5 females i n Category II returned with lambs. Based on the date when they i s o l a t e d themselves and the date when they r e t u r n e d t o South Slope without a lamb, the u n s u c c e s s f u l females i n Category II l o s t t h e i r lambs when they were l e s s than 20 days o l d . The females i n Category II which l o s t t h e i r lambs, r e t u r n e d to South Slope between May 10 and May 20. Those which d i d not l o s e t h e i r lambs returned more than one month l a t e r i n e a r l y J u l y (Figure 4 ) . FEMALE I.D. # 13 12* 94-+ 'a " 1 1 • • 11 1 1 1 — 1 — - H 2 ' 3 1 • ' : 1 1 - l i 1 1 i - u - u 1 l +++- — — — A — 1 1 1 1 •4 -+-H 1 23 H 1-CATEGORY* I 4 - H 1 2 6 +H-++H 1 2 7 t i n 11 . 1 2 3 +-H—f+J 11 +-1 ' 2 ' H 1 •4' ,3 ,- + H-•4' - H 1 H 1-H r-H r-20 30 APRIL 10 20 30 MAY „ A T E 9 19 JUNE 29 9 19 JULY 29 CATEGORY II •Category I - those females which used' the South Slope lambing grounds. Category II - those females which left South Slope to lamb in an unknown area. 1 r- female observed without a lamb on South Slope, female observed nursing a lamb on South Slope. rtical bars indicate at least one observation per day. 1 - i s o l a t i o n 2 - p a r t u r i t i o n 3 - reappearance on South S lope . 4 - l o s s of o f f s p r i n g . - numbers i n quotes are est imated d a t e s . F i g u r e 4. P a t t e r n of b i r t h and s u r v i v a l o f lambs from i d e n t i f i e d female bighorn on F l a t i r o n Mountain. 38 N u t r i t i o n a l and Disease Status of Females i n Late G e s t a t i o n Weights, Measurements, and Body C o n d i t i o n Scores Mean weights and lengths ( + /- SD) of a d u l t females from F l a t i r o n Mountain were as f o l l o w s : l i v e w e i g h t 61.6 +/- 4.1 kg (range 56.7 to 68.0 kg), t o t a l l e n g t h 1608 +/- 69 mm (range 1470 to 1700 mm), and h i n d f o o t l e n g t h 393 +/- 16 mm (range 363 to 420 mm) (Table 3 ) . The mean c h e s t g i r t h of a d u l t females was 1011 + /-41 mm (n=ll) , and the c h e s t g i r t h of the female lamb was 775 mm. Liveweight was s i g n i f i c a n t l y c o r r e l a t e d with c h e s t g i r t h 2 (r =0.79). The mean l i v e w e i g h t of 17 a d u l t females from Vaseux Lake was the same as F l a t i r o n females a t 61.6 kg (Table 5 ) . Female l i v e w e i g h t s of nine Okanagan Game Farm r e s e a r c h bighorn i n e a r l y s p r i n g were s i g n i f i c a n t l y lower than the f r e e - r a n g i n g p o p u l a t i o n s a t 46.8 kg (Table 5 ) . The Okangan Game Farm bighorn o r i g i n a t e d from the Vaseux Lake p o p u l a t i o n i n 1977 (E c c l e s and Shackleton 1979). Body c o n d i t i o n scores of 11 Ashnola females v a r i e d from 1.5 to 3.0 with a mean score of 2.3 +/- 0.5 (Table 3 ) . The female lamb had the l e a s t lumbar f a t r e s e r v e s and scored 1.5. The mean score value of 2.3 was s i g n i f i c a n t l y l a r g e r than the mean score of 1.8 +/- 0.4 (Harper unpubl.) found i n the Game Farm a d u l t females (chi-squared = 2.78). Although 27% of the Ashnola females ranked a t the uppermost s c a l e of 3.0, none of the Game Farm females ranked so h i g h . At the other end of the s c a l e 10% of the 39 Table 5. Weights of C a l i f o r n i a bighorn sheep from s o u t h - c e n t r a l B r i t i s h Columbia. Weight i n kg Homogeneous Po p u l a t i o n Month/Year x sd n Subsets F l a t i r o n Mountain 03/83 61.6 4.1 10 a Vaseux Lake 03/84 61.6 3.9 17 a OK Game Farm 04/83 46.8 3.8 9 b 40 Game Farm females ranked 1.0, but none of the females from F l a t i r o n Mountain had such a low s c o r e . Blood and T i s s u e Chemistry In blood serum from F l a t i r o n bighorn, a d u l t female t r a c e element l e v e l s were twice t h a t of the female lamb f o r selenium, copper, and z i n c (Table 4 ), but the serum c o n c e n t r a t i o n of i o d i n e , c a l c i u m , and magnesium d i d not d i f f e r a p p r e c i a b l y between the a d u l t s and the lamb. Inorganic phosphorus c o n c e n t r a t i o n i n the lamb serum was almost twice the mean l e v e l of the a d u l t females (Table 4 ) . In l i v e r and kidney t i s s u e , a d u l t male t r a c e element c o n c e n t r a t i o n s were ap p a r e n t l y lower than the mean of non-males (female #5, her f e t u s , and a newborn lamb) f o r i r o n , z i n c , and selenium (Table 6) . Conversely, copper l e v e l s were ap p a r e n t l y higher i n a d u l t male l i v e r and kidneys. Manganese l e v e l s were not c o n s i s t e n t l y d i f f e r e n t i n both t i s s u e s , with kidney l e v e l s being higher i n the males, and l i v e r l e v e l s being higher i n the non-males (Table 6) . In order to e s t a b l i s h some b a s e l i n e l e v e l s of t r a c e elements i n bighorn l i v e r and kidney t i s s u e , data from the Vaseux Lake, C r a t e r Mountain, F l a t i r o n Mountain, and B i g Bar po p u l a t i o n s were combined (Appendix 3) . Compared to the o v e r a l l means f o r s o u t h - c e n t r a l B.C., i r o n , z i n c , and selenium l i v e r l e v e l s were lower i n F l a t i r o n males. Non-males from F l a t i r o n , however, had r e l a t i v e l y higher l e v e l s of l i v e r i r o n and kidney 41 Table 6. Trace mineral c o n c e n t r a t i o n s of l i v e r and kidney t i s s u e on a wet weight b a s i s from male and female bighorn from F l a t i r o n Mountain. L i v e r (mg.kg - 1. Kidney (mg .kg Element Sex* ^  x sd n x sd n Iron Males 55 12 7 64 26 4 Non-males 173 38 3 91 27 3 Copper Males 81 19 7 4.5 1.1 4 Non-males 67 45 3 3.8 1.1 3 Zinc Males 33 6 7 22 6 4 Non-males 71 35 3 32 14 3 Manganese Males 3.2 0.7 7 2.0 0.9 4 Non-males 4.0 1.3 3 1.2 0.3 3 Selenium Males 0.18 0.06 7 — — — Non-males 0.27 0.09 3 - - -* Males were a l l hunter-harvested a d u l t s . Non-males c o n s i s t e d of one a d u l t female t r a p p i n g m o r t a l i t y (I.D. #5, t a b l e 2), her 95-105 day o l d f e t u s , and one r o a d - k i l l e d newborn female lamb. 42 z i n c compared to the o v e r a l l means i n Appendix 3. Both copper and manganese kidney l e v e l were lower i n F l a t i r o n non-males than the s o u t h - c e n t r a l B.C. average. A l l the other t i s s u e l e v e l s i n the F l a t i r o n p o p u l a t i o n were s i m i l a r to the average f o r s o u t h - c e n t r a l B.C. (Appendix 3 ). Disease Incidence A n a l y s i s of the n a s a l swabs i n d i c a t e d the presence of four s p e c i e s of b a c t e r i a and one s p e c i e s of v i r u s . A 30 to 50% i n c i d e n c e of the f o l l o w i n g three non-pathogenic b a c t e r i a was found: F l a v o b a c t e r spp., non-hemolytic Corynebacterium spp., and al p h a - S t r e p t o c o c c u s . Two of s i x n a s a l swabs i s o l a t e d hemolytic Staphylococcus aureus, a p o t e n t i a l l y pathogenic bacterium. A l l 12 n a s a l swabs were negative f o r the presence of P a s t e u r e l l a  spp. and hemolytic Corynebacterium pyogenes. V i r a l n a s a l swabs were a l l negative f o r bovine v i r a l d i a r r h e a (BVD), i n f e c t i o u s bovine r h i n o t r a c h e i t i s (IBR), and adenovirus. However, s i x of twelve bighorn females were i n f e c t e d with p a r a i n f l u e n z a type-3 (PI-3) v i r u s a t the time of sampling. The Rapid P l a t e Test on s i x serum samples f o r B r u c e l l a spp. a n t i b o d i e s were a l l n e g a t i v e , as were s e r o l o g i c a l t e s t s f o r the presence of L e p t o s p i r a spp. a n t i b o d i e s . 43 Pro d u c t i o n and S u r v i v a l of O f f s p r i n g During the Lambing P e r i o d C l a s s i f i c a t i o n Censuses of the F l a t i r o n Mt. P o p u l a t i o n P e r i o d i c censuses of F l a t i r o n Mountain from A p r i l 23 to June 11, 1983, showed t h a t the number of females observed on the w i n t e r - s p r i n g range of F l a t i r o n Mountain d e c l i n e d from 70 i n l a t e A p r i l t o 50 animals by May 3 when females were l e a v i n g the herd presumably to g i v e b i r t h (Figure 5B) . The number of females observed remained a t approximately 50 u n t i l May 10, a f t e r which i t i n c r e a s e d to 58 by May 21. The number of females observed d i d not r e t u r n to pre-lambing p e r i o d l e v e l s u n t i l May 24, and then remained at approximately 70 females u n t i l a t l e a s t June 11. This exodus of animals from South Slope f o r a p e r i o d of one month c o i n c i d e d with a steady i n c r e a s e i n the number of lambs observed (Figure 5A). The p a t t e r n of lamb o b s e r v a t i o n s through the lambing p e r i o d i n d i c a t e d t h a t p a r t u r i t i o n o ccurred over a p e r i o d of approximately 1 month between A p r i l 22 and May 22 (Figure 5A) . Assuming t h a t the o b s e r v a t i o n of a d d i t i o n a l newborn lambs re p r e s e n t s f u r t h e r p a r t u r i t i o n s , and the p a t t e r n of lamb s u r v i v a l does not vary a p p r e c i a b l y throughout the lambing p e r i o d , the mean " b i r t h d a t e " (+/- SD) of lambs i n 1983 was May 7 +/- 11 days. The a c t u a l mean b i r t h d a t e was probably a few days e a r l i e r because most lambs were not observed u n t i l they were 2 to 4 days o l d . Less f r e q u e n t surveys i n 1982 i n d i c a t e d a steady i n c r e a s e i n lamb 1 2 Maximum number o f lambs on South S l o p e 70 Maximum number o f a d u l t _ _ f e m a l e s 6 0 on S o u t h S l o p e 50 lambing p e r i o d : j »» r* ^ •** »' - fit' - J s — f L 1 1 1 1 1 1 1 1 i 1 1 1 X \ X ' " ~ -1 \ \ \ l 1 ** * 1 1 1 1 1 1 v>.-.-... 1 1 1 . V . V j . V . ••••+Y 1 1 20 24 28 A p r i l 10 14 18 May 22 26 30 7 11 June F i g u r e 5 . (A) P a t t e r n o f o b s e r v a t i o n o f newborn lambs on F l a t i r o n Mountain i n 1983. (B) P a t t e r n oJ o b s e r v a t i o n of a d u l t females on F l a t i r o n Mountain i n 1983 i n d i c a t i n g i s o l a t i o n o f pregnant females d u r i n g the lambing p e r i o d . * broken l i n e s indicate f u l l counts of lambs were not obtained. ** arrows i n d i c a t e p e r i o d s when t o t a l number o f lambs o b s e r v e d d e c l i n e d due t o known l o s s e s . *** shaded a r e a s i n d i c a t e p e r i o d s when t h e r e were no o b s e r v a t i o n s . X = mean " b i r t h d a t e " o f lambs (May 7). 45 numbers through l a t e A p r i l to e a r l y May. When lamb pr o d u c t i o n was censused more f r e q u e n t l y i n 1983, and 13% of the females were tagged, three p e r i o d s where the number of lambs decreased were i d e n t i f i e d . These were A p r i l 28 to 30, May 12 to 18, and May 26 to June 6 (Figure 5A) . The maximum counts of lambs were 23 on June 18, 1982 and 20 on J u l y 26, 1983. Using the maximum count of females 2 years and o l d e r (Table 7) , the lamb t o female r a t i o s f o r 1982 and 1983 were 0.28 and 0.24 r e s p e c t i v e l y . Lamb pr o d u c t i o n i n 1984 was l e s s than e i t h e r of these years with a maximum count of onl y 14 lambs ( M i n i s t r y of Environment f i l e s , P e n t i c t o n ) . Once the bighorn lambs reach approximately one month of age then t h e i r subsequent s u r v i v a l r a t e i s h i g h . Maximum counts of lambs from June, 1982 to May, 1983 of the f o l l o w i n g year i n d i c a t e an o v e r a l l s u r v i v a l r a t e of 82%, wit h l o s s e s being evenly d i s t r i b u t e d throughout the year (Figure 6) . Seventeen of the 20 lambs produced i n 1983 s u r v i v e d to May of 1984, a s u r v i v a l r a t e of 85%. V o c a l i z a t i o n and Search Behaviour of Females E a r l y i n the lambing p e r i o d i t was p o s s i b l e t o i d e n t i f y i n d i v i d u a l l y the seven females which were l e a d i n g lambs. Two of them were c o l l a r e d , one had a un i q u e l y l i g h t - c o l o u r e d pelage (#13) , and the remaining f o u r were i n d i f f e r e n t stages of the moult, v a r y i n g from a f u l l w inter coat to a f u l l summer coa t . On Table 7. Monthly maximum classification counts of bighorn sheep on the Flatiron Mountain transect i n 1982 and 1983. Ratios i n parentheses of lambs, yearlings and adult males to adult females are also shown based on yearly maxima. FEMALES MALES NUMBER OF LAMBS YEARLINGS 2YR+ 2YR+ TOTAL SURVEYS MONTH 82 83 82 83 82 83 82 83 82 83 82 83 FEB - 1 9 - - - 82 - 06 - 107 - 4 APRIL 7 7 16 19 58 70 22 35 103 131 3 4 MAY 21 16 17 14 46 72 26 44 110 147 8 6 JUNE 23 15 11 15 81 70 1 44 116 144 4 5 JULY 23 20 15 9 66 48 4 1 108 78 6 1 AUG - 2 0 - - - 67* 2 89 - 3 OCT 17 - - - 62* - 5 83 - 4 -NOV 20 - - - 92* - 38 - 150 3 -DEC 20 - - - 86* - 37 - 143 - 4 -YR MAX 23 20 17 19 81 82 38 44 161" 165~ 32 23 RATIO(. .28) (.24)(.21)(.23) (.49)(.54) * - counts of females i n late summer and f a l l include yearlings. - yearly maximum total numbers of sheep are calculated by summing yearly maxima for each age-sex class. 47 number of f e t u s e s 80h p r e d i c t e d by pregnancy d i a g n o s i s / 60 Number of Lambs 40 20 • • a^^p m m m i^B^p»-maximum counts of lambs maximum count of y e a r l i n g s (1982 cohort ) 6 8 10 11 1 2 MONTH F i g u r e 6. S u r v i v a l of bighorn lambs on South Slope from June, 1982 to May 1983 based on pregnancy d i a g n o s i s i n 1983, and maximum counts o f lambs and y e a r l i n g s . 48 A p r i l 30, 1983 one of these seven females, i n d i v i d u a l l y i d e n t i f i e d the previous day by i t s p a t t e r n of winter coat moult, was observed by h e r s e l f running back and f o r t h on South Slope, st o p p i n g f r e q u e n t l y i n a head-up a l e r t p o sture, and v o c a l i z i n g l o u d l y and c o n s t a n t l y . At t h i s time there were no other sheep i n s i g h t and t h i s female was not f o l l o w e d by a lamb. L a t e r the same day a d i f f e r e n t female, t h i s time i n the company of two other u n c o l l a r e d females, was seen to approach a group of females and y e a r l i n g s w h i l e v o c a l i z i n g c o n s t a n t l y . The same a f t e r n o o n , female #13 was observed v o c a l i z i n g c o n s t a n t l y and t r a v e l l i n g a t a steady pace while i n the company of two other females. Thus a t o t a l of three d i f f e r e n t females were observed to e x h i b i t the unusual behaviour of t r a v e l l i n g and constant v o c a l i z i n g on A p r i l 30, 1983. I t was dusk b e f o r e the nursery group, c o n s i s t i n g of s i x females (two tagged) and f i v e lambs, was s i g h t e d . The lamb count f o r A p r i l 30 was t h e r e f o r e two l e s s than the count on A p r i l 29, t h i s d i f f e r e n c e being accounted f o r by the l o s s of lambs belo n g i n g to two i d e n t i f i e d females (Figure 5A). On May 9, 1983 another s o l i t a r y female was observed t r a v e l l i n g and v o c a l i z i n g f o r a p e r i o d of 30 min. T h i s female was v o c a l i z i n g a t a r a t e of 0.8 .min 1 , g r a z i n g very i n f r e q u e n t l y , and was almost c o n s t a n t l y m a i n t a i n i n g a head-up a l e r t p o s t u r e . On May 10, 1983 another t r a v e l l i n g , v o c a l i z i n g female was observed. T h i s female v o c a l i z e d a t a r a t e of 16 c a l l s . m i n - 1 , t r a v e l l e d with a head-up a l e r t p o s t u r e , and o n l y 49 i n f r e q u e n t l y stopped to graze. A f t e r not being observed f o r 26 days, female #4 returned to South Slope on May 20, 1983, and was observed v o c a l i z i n g and t r a v e l l i n g e x t e n s i v e l y among groups of sheep, s n i f f i n g other females' lambs. On two occasions w i t h i n 1 h she ran to groups of lambs, s n i f f i n g a t o t a l of f i v e lambs d u r i n g one 8 min p e r i o d . The lambs i n each case u s u a l l y f l e d to t h e i r dam. A c t i v i t y sampling i n d i c a t e d she spent l e s s than 30% of her a c t i v e time g r a z i n g , i n s t e a d she maintained a head-up a l e r t posture, and v o c a l i z e d w h ile t r a v e l l i n g or s t a n d i n g . Two separate samplings r e v e a l e d female #4 v o c a l i z e d a t a r a t e of 10.9 and 12 c a l l s . m i n 1 when i n the head-up a l e r t p o s t u r e . The f o l l o w i n g day female #4 d i d not e x h i b i t the v o c a l i z i n g and lamb s n i f f i n g behaviour. She d i d , however, a s s o c i a t e with the nursery group a t l e a s t u n t i l May 26, but was not with them on June 6, 1983. On June 7, 1983 f o u r a d u l t females i n c l u d i n g female #12 were observed t r a v e l l i n g r a p i d l y and v o c a l i z i n g as p a r t of a group of 5 females, 2 y e a r l i n g s , and 1 lamb. They approached another group of 3 females and 1 lamb, whereupon 3 of the females s n i f f e d t h a t lamb. The group then q u i c k l y r e t u r n e d over the r i d g e only to r e t u r n 10 min l a t e r w i t h an a d d i t i o n a l 3 females and 7 lambs. I t appeared t h a t these females had found t h e i r lambs because no f u r t h e r v o c a l i z a t i o n and t r a v e l l i n g behaviours were observed that day. 50 P o t e n t i a l F a c t o r s A f f e c t i n g Lamb S u r v i v a l Weather During Lambing C l i m a t o l o g i c a l r e c o rds covered an "extended" lambing p e r i o d of 39 days from A p r i l 23 t o May 31, 1983 to document any a f f e c t s weather might have on the s u r v i v a l of lambs to two weeks of age (the l a s t documented p a r t u r i t i o n o ccurred on May 18) . There was c o n s i d e r a b l e v a r i a t i o n i n the c l i m a t i c v a r i a b l e s recorded at HT3 du r i n g the lambing p e r i o d of 1983 (Figure 7). However, p e r i o d s of high lamb m o r t a l i t y were not a s s o c i a t e d with the f r e e z i n g temperatures and p r e c i p i t a t i o n of A p r i l 23 to 26, and May 8 to 10, which r e s u l t e d i n an accumulation of 6 to 7 cm of snow a t the upper e l e v a t i o n s of the lambing grounds. Of the three p e r i o d s where lamb numbers n o t i c a b l y d e c l i n e d (Figure 5A) , two occ u r r e d d u r i n g and a f t e r p e r i o d s of i n c r e a s i n g temperatures, d e c l i n i n g humidity, and no p r e c i p i t a t i o n (Figure 7) . The known d e c l i n e i n lamb numbers t h a t occurred between May 12 and 18 was, however, a s s o c i a t e d with a storm which r e s u l t e d i n 9 mm of p r e c i p i t a t i o n , but temperatures were not as c o l d as those a s s o c i a t e d with the f i r s t two storms. While p o s t n a t a l m o r t a l i t i e s were probably o c c u r r i n g throughout the lambing p e r i o d , there c e r t a i n l y was not a p a t t e r n which r e f l e c t e d a response to inclement weather. In f a c t , more lambs were observed a f t e r the most severe storm of A p r i l 23 t o 26, than were observed before i t . A l s o , based on o b s e r v a t i o n s oh the lambing grounds, the females and newborn 5 1 85 + 80 > •H E -*-> 3 io 6 E H •H 3 41 G E M • •H -rt > , G X * J 4 J IB C -H > i 6 CO T3 •H T> i-i e is c oi 3 a at c o •H 10 •H a t-H -H fl o — •M 0) E o n e t« a— E 3 E E •H 3 C E •H -H E X io 60-40 20 8-6-4 -2-28 24 o 20 o >i E 0) 01 i-l -H Cu •H -o E 10 C E 01 16-12-8-+ 4-0--4--8-22 26 30 s n o w f a l l 1 t o t a l p p t 24 28 3 m U-l 2 O E c o , to •— 22 26 30 8 12 16 20 24 28 22 26 APRI L 30 12 16 IA Y 20 24 28 F i g u r e 7. Weather p a t t e r n s i n the Ashnola a t 1585 m (HT3) du r i n g the 19 83 lambing p e r i o d . * shaded areas i n d i c a t e p e r i o d s when the t o t a l number of lambs d e c l i n e d due to known l o s s e s (See F igu re 5A). ** V e r t i c a l bars showing t o t a l p r e c i p i t a t i o n accumulated over the p e r i o d covered by the p reced ing h o r i z o n t a l arrow. 52 lambs made c o n s i d e r a b l e use o f s h e l t e r i n the form of c l i f f o v e r h a n g s , s h a l l o w c a v e s , and mature D o u g l a s - f i r t r e e s . T h i s b e h a v i o u r a l t h e r m o r e g u l a t i o n would have moderated some of the thermal s t r e s s e x p e r i e n c e d by n e o n a t a l and e a r l y p o s t n a t a l lambs. The South S lope lambing grounds v a r y i n e l e v a t i o n from 1050 m to 1585 m. Ground l e v e l temperatures were s i g n i f i c a n t l y warmer a t 1065 m (TI) compared to 1585 m (T2) . The mean minimum and maximum temperatures from A p r i l 23 to May 3 1 , 1983 a t 1065 m e l e v a t i o n were + 7 . 1 ° a n d + 1 6 . 2 ° C r e s p e c t i v e l y . At 1585 m the mean minimum and maximum temperatures were + 1 . 7 ° and + 1 2 . 6 ° C r e s p e c t i v e l y . Mean minimum and maximum temperatures a t the lower e l e v a t i o n of the lambing grounds were 5 . 4 ° and 3 . 6 ° C warmer r e s p e c t i v e l y . The lower p a r t o f the South S lope lambing grounds was an a r e a where females w i t h newborn lambs were f r e q u e n t l y o b s e r v e d . S i n c e the m i c r o c l i m a t e t h a t newborn lambs e x p e r i e n c e a t ground l e v e l c o u l d be d i f f e r e n t than t h a t h i g h e r above the g round , temperatures a t ground l e v e l ( T 2 ) and temperatures 1.5 m above the ground i n a Stevenson s c r e e n (HT3) were compared a t an e l e v a t i o n o f 1585 m. O v e r a l l , f o r the extended lambing p e r i o d , ground l e v e l minimum and maximum temperatures were 1 . 1 ° a n d 0 . 6 ° C c o l d e r r e s p e c t i v e l y . However, f u r t h e r a n a l y s i s r e v e a l e d t h a t ground temperatures were c o l d e r o n l y d u r i n g p e r i o d s f r e e of 52a Leaf 53 missed i n numbering. 53a p r e c i p i t a t i o n . During the 15 days of the extended lambing p e r i o d t h a t p r e c i p i t a t i o n f e l l , ground l e v e l minimum and maximum temperatures a t 1585 m were 0.8° and 0.7° degrees C. warmer than those i n the Stevenson screen. I t was d u r i n g those days of p r e c i p i t a t i o n t h a t temperatures were lowest and thermal s t r e s s on the neonate would be h i g h e s t . S u c k l i n g Behaviour A t o t a l of 195 s u c k l i n g bout d u r a t i o n s were timed on F l a t i r o n Mountain from l a t e A p r i l t o e a r l y June, 1983. The mean suc k l e d u r a t i o n was 21.9 +/- 9.9 seconds. Only lambs l e s s than 10 days o l d terminated s u c k l i n g bouts, and these accounted f o r 22 (11.3%) of the s u c k l i n g bouts timed. The remaining s u c k l e s were terminated by females s t e p p i n g over t h e i r lambs' heads and breaking c o n t a c t with the udders. One-way ANOVA of the e f f e c t of lamb age on the d u r a t i o n of the s u c k l i n g bout r e v e a l e d two homogeneous subsets. Lambs l e s s than 10 days o l d s u c k l e d s i g n i f i c a n t l y longer on average (x=24.3 s) than the other two a g e - c l a s s e s (F=11.67, Table 8). The second subset, i n c l u d e d female terminated s u c k l i n g bouts with lambs both 11 to 25, and 26 to 60 days o l d , and averaged 19.2 s and 18.4 s r e s p e c t i v e l y . There were no a s i g n i f i c a n t d i f f e r e n c e s among mean d u r a t i o n s of tagged and untagged females, r e g a r d l e s s of whether they l o s t t h e i r lambs or not (One-way ANOVA, F=0.85). Table 8. Suckling behaviour of bighorn lambs for the Flatiron Mountain population between April 27 and June 11,1983. Estimated Age (days) Suckle Duration (s) Suckle Rate Total Suckle Duration Rate x sd n (bouts.h-1) (sJi - 1) x Bunt Rate (bunts.s ^  of suckling) x sd n 1-10 24.3 1.6 60 a 3.2 75 0.30 .26 18 3. 11-25 19.2. 1.4 51 b 2.0 29 0.4^ .18 25 26-60 18.4, 1.3 84 b 0.7b 14 0.44b .19 42 Means within columns with different subscripts are significantly different. 54 The s u c k l e r a t e of lambs 1 to 10 days o l d was 3.2 bouts.h and was s i g n i f i c a n t l y more fre q u e n t than the bout r a t e of 0.7 bouts.h 1 f o r lambs 26-60 days o l d . The sample s i z e of s u c k l e r a t e s f o r lambs 11 to 25 days o l d was i n s u f f i c i e n t to a l l o w s t a t i s t i c a l comparisons. The bunt r a t e of 5 lamb terminated s u c k l e s was 0.14 bunts.s 1 and was s i g n i f i c a n t l y d i f f e r e n t from the bunt r a t e of 80 female terminated s u c k l e s t h a t was 0.43 b u n t s . s - 1 (One-way ANOVA, F=10.2). The mean bunt r a t e of lambs 1 to 10 days o l d was a l s o s i g n i f i c a n t l y l e s s a t 0.30 bunts.s ^ compared to lambs 11 to 60 days o l d which averaged 0.45 bunts.s 1 (One-way ANOVA, F=3.5, Table 8). D i r e c t Observations of Predators Golden eagles were observed on three occasions a t t a c k i n g groups of sheep which contained j u v e n i l e s . On A p r i l 25, 1982, an immature eagle was observed d i v i n g a t and hovering one to two meters above a group of females and y e a r l i n g bighorn f o r a p e r i o d of 15 min before f l y i n g away. The sheep gathered i n a t i g h t group but d i d not f l e e , with the y e a r l i n g appearing to o b t a i n p r o t e c t i o n by c r o u c h i n g beside the a d u l t females. On May 6, 1982, the main nursery group was observed f l e e i n g to escape t e r r a i n pursued by two mature eagles i n r a p i d , low l e v e l f l i g h t . A l l the lambs were able to keep up with the a d u l t females, but the outcome of t h i s p u r s u i t was unknown. On May 24, 1983, a mature eagle was observed d i v i n g on a group of lambs bedded on a 55 l a r g e f l a t r ock. The eagle came w i t h i n 1 m of s t r i k i n g one of the lambs, whereupon the e n t i r e nursery group f l e d immediately to c l i f f escape t e r r a i n and remained s t a n d i n g i n a t i g h t group f o r 10 min b e f o r e bedding down. These eagle-bighorn i n t e r a c t i o n s were unusual because golden eagles were observed o f t e n , throughout the year and d u r i n g the lambing p e r i o d , i n the pr o x i m i t y of bighorn without e i t h e r s p e c i e s r e a c t i n g to the presence of the o t h e r . Black bear s i g h t i n g s were q u i t e common i n the study a r e a . A B.C. M i n i s t r y of Environment crew observed f i v e d i f f e r e n t bears on J u n i p e r Slope i n the summer of 1982, based on v a r i a t i o n s i n the c o l o u r phase and s i z e of these bears. Black bears were observed as e a r l y as the f i r s t week of May so they c o u l d p o t e n t i a l l y prey on newborn lambs. Bears' were observed more o f t e n on J u n i p e r Slope, an area not used by bighorn i n the s p r i n g , i n both 1982 and 1983. No bear-bighorn i n t e r a c t i o n s were observed. A s i n g l e red fox was observed on the South Slope lambing grounds on May 22, 1984. A s o l i t a r y female bighorn, t h a t was on the t r a v e l route of the fox, h i d below some rock b l u f f s u n t i l the fox had passed. The fox d i d appear to be aware of the presence of the b i g h o r n . Although a t o t a l of on l y seven coyotes were observed during the course of f i e l d work (three i n d i v i d u a l s , and one group of 56 f o u r ) , coyote t r a c k s were common at a l l times of the year on the bighor n w i n t e r - s p r i n g range. Based on t r a c k s and scent posts to i n d i c a t e a c t i v i t y c e n t e r s , a minimum estimate of three f a m i l y groups of f i v e coyotes each o c c u r r e d i n the v i c i n i t y of F l a t i r o n Mountain. On South Slope s i n g l e coyotes were observed on two occasions i n c l o s e a s s o c i a t i o n with b i g h o r n . On March 28, 1983, a coyote was observed approximately 70 m from two a d u l t females t h a t were bedded on open range near the f o r e s t edge. The coyote appeared to be aware of the bighorn as i t approached, s i n c e i t went i n t o the t r e e s when i t had reached a p o s i t i o n where the bighorn c o u l d see i t on the open range. On A p r i l 29, 1983, a s i n g l e t r o t t i n g coyote was observed to make a b r i e f a t t a c k on two a d u l t female b i g h o r n running towards a l a r g e group of sheep on South Slope. The coyote and the bighorn were heading s t r a i g h t towards each o t h e r , and when the coyote t r i e d t o cut the bighorn o f f , they changed d i r e c t i o n to a v o i d the coyote and a c c e l e r a t e d t h e i r run. The coyote then slowed to i t s b r i s k t r o t and disappeared over the r i d g e i n the o p p o s i t e d i r e c t i o n of the bigho r n . Contents of Predator Scats i n Spring A t o t a l of 81 predator s c a t s were c o l l e c t e d , most of which were coyote s c a t s , s i n c e none were a s s o c i a t e d with scrapes. However, i t i s p o s s i b l e t h a t some F e l i d or Canid s c a t s other than coyote were i n c l u d e d i n the sample. Twenty-four percent of the 57 t o t a l volume of s c a t s c o l l e c t e d c o n s i s t e d of h a i r and bone fragments of bighorn lambs, while a d u l t remains amounted to 10% by volume. Thus, approximately 34% the p r e d a t o r s ' e a r l y s p r i n g d i e t c o n s i s t e d of bighorn sheep. On a frequency occurence b a s i s , 38 of the 81 sc a t s (47%) contained the remains of e i t h e r lambs or a d u l t b i g h o r n . Twenty-nine percent contained o n l y lamb h a i r , 12% contained only a d u l t h a i r , and 6% contained both a d u l t and lamb remains. Of those s c a t s which contained lamb h a i r , the average volume was 68%. The p r o p o r t i o n of a d u l t bighorn i n the d i e t of coyotes may have been overestimated because some of the s c a t s c o l l e c t e d may have r e c e n t l y thawed from the p r e v i o u s w i n t e r , and thus would not re p r e s e n t predator food h a b i t s i n e a r l y s p r i n g . The p r o p o r t i o n of lambs i n the p r e d a t o r s ' d i e t c o u l d not be b i a s e d by i n c l u s i o n of o l d s c a t s however, because none of these were g r e a t e r than nine months o l d when c o l l e c t e d . 58 DISCUSSION Timing of O f f s p r i n g M o r t a l i t y Pregnancy Rate Assuming the sample of 11 females i s r e p r e s e n t a t i v e of the p o p u l a t i o n as a whole, the 100% pregnancy r a t e i n mid to l a t e g e s t a t i o n c l e a r l y leads to r e j e c t i o n of the hypothesis t h a t there i s no d i f f e r e n c e between the pregnancy r a t e and the r a t e of lamb p r o d u c t i o n . The cause of low rec r u i t m e n t i s t h e r e f o r e not low con c e p t i o n . The assumption t h a t the sample i s r e p r e s e n t a t i v e i s open to some q u e s t i o n , because i t i s p o s s i b l e t h a t the i n c r e a s e d energy requirement of g e s t a t i o n may have d i f f e r e n t i a l l y a t t r a c t e d pregnant females to food used as b a i t i n t r a p p i n g . When a d u l t females were trapped i n 1977 f o r the Okanagan Game Farm study, from the Vaseux Lake p o p u l a t i o n , a l l 16 gave b i r t h to v i a b l e lambs, with two producing twins ( E c c l e s and Shackleton 1979). My estimate of pregnancy i n 1984 f o r another trapped sample of the Vaseux p o p u l a t i o n was 93%, based on serum progesterone and Doppler u l t r a s o u n d d i a g n o s i s (Harper unpubl.). While age-sex c l a s s e s other than a d u l t females were a l s o captured, i n both cases food was used to l u r e sheep i n t o the t r a p s . However, i n a mixed r o a d - k i l l and shot sample of Vaseux females c o l l e c t e d i n 1965 and 1966, Sp a l d i n g (1966) found a pregnancy r a t e of 91% with 59 4 cases of twins i n 11 females. A l s o , i n a l a r g e sample of D a l l ' s sheep (Ovis d a l l i d a l l i ) females shot and autopsied i n the Northwest T e r r i t o r i e s , 78% of females 2-years and o l d e r , and 3 of 7 female y e a r l i n g s were pregnant, (Simmons e t a_l. 1984) . A l l eig h t e e n a d u l t female D a l l ' s sheep a u t o p s i e d i n Alaska were pregnant (N i c h o l s 1978) and w i l d A s i a t i c sheep (Ovis o r i e n t a l i s ) a u t o p s i e d i n Iran a l s o showed a 100% pregnancy r a t e i n females 3-years and o l d e r (Valdez 1976) . I t would t h e r e f o r e seem t h a t pregnant females are probably not d i f f e r e n t i a l l y a t t r a c t e d to b a i t e d t r a p s , and i t i s common f o r females i n w i l d Ovis p o p u l a t i o n s to have high pregnancy r a t e s . Although a 100% pregnancy r a t e was determined, senescent domestic ewes may not conceive near the end of t h e i r r e p r o d u c t i v e l i f e (Nalbandov 1976) . S i m i l a r l y , i t i s probable t h a t few of the 2-year o l d females would have a t t a i n e d s u f f i c i e n t weight to conceive as y e a r l i n g s ( G e i s t 1971). Observation of marked D a l l ' s sheep females i n d i c a t e d n a t a l i t y was >80% i n females 5-years and o l d e r , but o n l y 50% of the 4-year o l d s and none of the 3-year o l d s gave b i r t h to l i v e lambs (Bunnell and Olsen 1981). Maximum counts i n 1983 i n d i c a t e d the F l a t i r o n Mountain p o p u l a t i o n c o n s i s t e d of 82 females two years and o l d e r (Table 7) . Using 50% of the y e a r l i n g s i n 1982 to estimate the number of 2-year o l d females as 9 i n 1983, r e s u l t s i n an estimate of 73 females of r e p r o d u c t i v e age (3-years and o l d e r ) . Assuming 5% of these mature females were beyond t h e i r r e p r o d u c t i v e l i f e f u r t h e r 60 reduces the estimate of pregnant females i n the p o p u l a t i o n to 69. So, i n the p o p u l a t i o n of 82 females 2-years and o l d e r , o n l y an estimated 69 females 3-years and o l d e r , based on my pregnancy r a t e , would have given b i r t h to 69 lambs. However, the maximum summer lamb count was o n l y 20 i n 1983. S u r v i v a l of Lambs from Tagged Females Observations of marked females i n d i c a t e 3 of 5 Category I females l o s t t h e i r lambs when the lambs were between 5 and 21 days o l d . Low lamb p r o d u c t i o n was not due to high neonatal m o r t a l i t y s i n c e a l l lamb l o s s e s of Category I females occurred when lambs were g r e a t e r than 3 days o l d . Low lamb p r o d u c t i o n was due to high e a r l y p o s t n a t a l m o r t a l i t y i n Category I females. C i r c u m s t a n t i a l evidence, based on the f a c t t h a t u n s u c c e s s f u l Category II females were away from South Slope from 18 to 26 days a f t e r f i r s t i s o l a t i n g themselves, suggest Category II females d i d not l o s e t h e i r lambs i n the f i r s t few days a f t e r p a r t u r i t i o n e i t h e r . T h i s i s based on the assumption t h a t Category II females i s o l a t e d themselves a few days b e f o r e p a r t u r i t i o n as the Category I females d i d , and r e t u r n e d to South Slope w i t h i n a few days of l o s i n g t h e i r lambs. The f a c t t h a t female #4, upon her r e t u r n to South Slope, e x h i b i t e d the v o c a l i z a t i o n and search behaviour t y p i c a l of dams s e a r c h i n g f o r m i s s i n g lambs, supports t h i s i d e a . T h i s behaviour should o n l y be e x h i b i t e d f o r a few days a f t e r the l o s s of an o f f s p r i n g . 61 Lamb p r o d u c t i o n from i d e n t i f i e d females was fou r of 11 or 36% i n 1983 (Figure 4) . Using the above estimated 69 pregnant females i n the p o p u l a t i o n , lamb p r o d u c t i o n from unmarked females 3-years and o l d e r i s then 16 of 58 or 28%. T h i s d i f f e r e n c e c o u l d be due to random v a r i a t i o n i n lamb s u r v i v a l among females, or may suggest there are more non-pregnant females i n the p o p u l a t i o n than i s p r e d i c t e d by the sampled pregnancy r a t e . S u r v i v a l r a t e s of lambs a f t e r they reached one month of age were high i n 1983 and 1984, a t 82% and 85% r e s p e c t i v e l y . The s u r v i v a l r a t e s of lambs from one month t o one year of age were lower i n the e a r l y 1960's, being 73% i n 1961 (Blood 1961) and 71% i n 1964 (Demarchi 1965). N u t r i t i o n a l and Disease Status of Females i n Late G e s t a t i o n Weights, Measurements, and Body C o n d i t i o n Scores Liveweights of Ashnola females were 32% higher than females from the Okanagan Game Farm r e s e a r c h herd, y e t they produced fewer lambs than t h a t c a p t i v e p o p u l a t i o n i n both 1982 and 1983 (28% and 24% versus 64% and 82%). S i m i l a r l y body c o n d i t i o n scores of Ashnola females were 28% higher than Okanagan Game Farm females. F l a t i r o n Mt. females are i n a b e t t e r s t a t e of n u t r i t i o n than Game Farm females. Thus the n u t r i t i o n a l s t a t u s of F l a t i r o n Mt. females i n mid to l a t e g e s t a t i o n should not a f f e c t lamb p r o d u c t i o n . W i t h i n the F l a t i r o n Mt. sample, the lowest weight 62 female was the lamb, which a l s o had the lowest body c o n d i t i o n score and the lowest c o n c e n t r a t i o n of c e r t a i n blood m i n e r a l s . In f a c t i f body c o n d i t i o n scores of the F l a t i r o n Mt. females are e q u i v a l e n t to scores i n domestic sheep, they are i n good f a t 2 c o n d i t i o n . Using the r e g r e s s i o n r e l a t i o n s h i p (r =0.88) determined f o r domestic sheep (Russel e t a_l. 1969) , the chemical f a t i n the f l e e c e - f r e e empty body should approximate 20% f o r a body c o n d i t i o n score of 2.3. Thus lamb b i r t h w e i g h t s from the Ashnola and Vaseux p o p u l a t i o n s should be above a l e v e l which would cause the hig h neonatal m o r t a l i t y t h a t i s r e l a t e d to low b i r t h w e i g h t s d e s c r i b e d by workers on domestic sheep (Thomson and Thomson 1949), and w i l d c e r v i d s (Verme 1965, 1977; Thorne e t a l . 1976). Compared to p u b l i s h e d weights of Oj_ c_^ c a l i f o r n i a n a the weights of the females captured i n t h i s study are he a v i e r than the mean of 53 kg given by Blood e t a_l. (1970). However, t h e i r sample s i z e was small (n=4) , and the range of weights g i v e n was high (48 to 66 kg) . The mean weight of a d u l t females from the Vaseux Lake p o p u l a t i o n i n winter of 1965-66 was 58.7 kg (n = 9, M i n i s t r y of Environment f i l e s , P e n t i c t o n ) . Both the Ashnola and the Vaseux p o p u l a t i o n s are winter f e d which may account f o r the higher weights obtained i n the 1980's compared to the 1960's. L i n e a r measurements of the F l a t i r o n Mt. females were a l s o l a r g e r than p u b l i s h e d mean measurements of Ovis canadensis with t o t a l l e n g t h being 81 mm longer and hind f o o t l e n g t h being 45 mm longer 63 (Lawson and Johnson 1982). Blood and T i s s u e Chemistry While there are no p u b l i s h e d data on the t r a c e mineral l e v e l s of bighorn sheep, there are s e v e r a l s t u d i e s which g i v e the c o n c e n t r a t i o n of the macrominerals c a l c i u m , phosphorus, and magnesium i n bighorn serum. Although data on t h e i r lamb pr o d u c t i o n i s not g i v e n , blood mineral l e v e l s i n other p o p u l a t i o n s of bighorn i n d i c a t e how they d i f f e r from the F l a t i r o n Mountain herd. Serum c a l c i u m i n F l a t i r o n females i s s i m i l a r to t h a t r e p o r t e d by Franzmann (1971, 1972), Franzmann and Thorne (1970), Hickey (1976), and Peterson and B o t t r e l l (1978) f o r Rocky Mountain and C a l i f o r n i a b i g h o r n . Free ranging d e s e r t bighorn (0.  c. n e l s o n i , 0. c. mexicana, and 0. c. cremnobates) however, have serum c a l c i u m c o n c e n t r a t i o n s ranging from 9.8 to 11.0 mg% which i s s l i g h t l y higher than the F l a t i r o n females (Bunch e t a l . 1980; McDonald e t a l . 1981; Deforge and S c o t t 1982). D a l l ' s sheep a l s o have s l i g h t l y higher serum c a l c i u m l e v e l s a t 9.6 mg%. (Foreyt et a l . 1983). Whereas there was l i t t l e v a r i a t i o n i n the p u b l i s h e d v a l u e s of serum c a l c i u m , i n o r g a n i c phosphorus c o n c e n t r a t i o n s v a r i e d from a low of 3.3 mg% i n w i l d bighorn a f t e r h a n d l i n g (Franzmann and Thorne 19 70) , to a high of 7.0 mg% i n c a p t i v e bighorn (Woolf and Kradel 1970) . Most s t u d i e s of w i l d sheep on n a t i v e forage give l e v e l s of serum i n o r g a n i c phosphorus v a r y i n g from 4.0 to 5.4 mg% 64 (Franzmann and Thorne 1970; Franzmann 1971, 1972; Hebert 1972; Hickey 1976; Peterson and B o t t r e l l 1978; Bunch e t a l . 1980; MacDonald e t a_l. 1981; Deforge and S c o t t 1982; Fo r e y t e t a l . 1983). One p o p u l a t i o n of Oj_ Cj_ n e l s o n i however, had lower than average i n o r g a n i c phosphorus serum l e v e l s of 3.6 mg% (McDonald e t a l . 1981). At 3.25 mg%, F l a t i r o n a d u l t females had lower serum i n o r g a n i c phosphorus than t h a t r e p o r t e d i n the l i t e r a t u r e . I t i s i n t e r e s t i n g to note t h a t the d e s p i t e having lower l e v e l s i n most serum m i n e r a l s , the female lamb had almost twice the c o n c e n t r a t i o n of serum i n o r g a n i c phosphorus of a d u l t females. In humans, phosphorus i s known to decrease with i n c r e a s i n g age, as i t s c o n c e n t r a t i o n i n blood i s c o r r e l a t e d to the r a t e of bone growth (Hillman 1983) . Chemical composition of the p r i n c i p a l forage s p e c i e s on the South Slope bighorn winter range has been determined to c o n t a i n s u f f i c i e n t crude p r o t e i n , f a t , f i b e r , ash, n i t r o g e n - f r e e e x t r a c t , and c a l c i u m f o r maintenance (Demarchi 1968). Phosphorus, however, was c o n s i d e r e d to be d e f i c i e n t , e s p e c i a l l y among g r a s s e s , s i n c e i t d e c l i n e d i n dry matter c o n c e n t r a t i o n from ranging from 0.06% to 0.12% i n August to 0.01% by March of the f o l l o w i n g year (Demarchi 1968) . However, i n a review by Cohen (1980) , i t was s t r e s s e d t h a t phosphorus i n rangeland ruminant n u t r i t i o n cannot be c o n s i d e r e d an i s o l a t e d n u t r i e n t and panacea f o r i l l - t h r i f t and i n f e r t i l i t y . While rangeland c a t t l e respond w e l l to phosphorus supplements, there are few r e p o r t s of p o s i t i v e responses to 65 phophorus supplementation i n domestic sheep (Cohen 1980) . I t i s not c l e a r what e f f e c t s low phosphorus i n bighorn winter forages and pregnant female serums had on the p r o d u c t i v i t y of F l a t i r o n b ighorn, but d e f i c i e n c i e s w i l l a f f e c t growth and s k e l e t a l development (Cohen 1980). However, domestic sheep are a b l e to supply the f e t u s with phosphorus i n d i r e c t r e l a t i o n to i t s s i z e and need, and back t r a n s f e r r e p r e s e n t s only 7% of the t r a n s f e r from female to f e t u s (Garel 1983) . I t i s p o s s i b l e t h a t the low phosphorus i n serum of pregnant females i s a response to high f e t a l demand. Magnesium l e v e l s were hig h e r than b a s e l i n e l e v e l s e s t a b l i s h e d by Franzmann (1971,1972) and Franzmann and Thorne (19 70), but were lower than Rocky Mountain bighorn from south-eastern B.C. (P. Davidson p e r s . comm.). Serum t r a c e element c o n c e n t r a t i o n s were obtained as a f i r s t step toward e s t a b l i s h i n g b a s e l i n e l e v e l s to a l l o w comparison among p o p u l a t i o n s . The o n l y comparable data comes from south-eastern B.C. (P. Davidson p e r s . comm.), where serum c o n c e n t r a t i o n s of selenium and copper were s i m i l a r to F l a t i r o n Mt. females, i o d i n e was lower, and z i n c l e v e l s were almost 4 times h i g h e r . Although energy s t a t u s of the F l a t i r o n Mt. females appeared to be adequate d u r i n g g e s t a t i o n , blood serum l e v e l s of copper, z i n c , and selenium, may be m a r g i n a l l y d e f i c i e n t based on the 66 adequate l e v e l s which have been e s t a b l i s h e d f o r domestic sheep (Puis 1981) . However, i o d i n e , c a l c i u m , and magnesium appear normal based on values f o r domestic sheep (R. Puis pers. comm.). Phosphorus i n blood serum of a d u l t females was lower than most p u b l i s h e d bighorn l e v e l s and the normal l e v e l e s t a b l i s h e d f o r domestic sheep. Co n c e n t r a t i o n s of t r a c e elements i n l i v e r and kidney t i s s u e are b e t t e r i n d i c a t o r s of s t a t u s than blood serum because they are storage t i s s u e s f o r many of these elements, whereas blood i s a homeostatic t i s s u e which w i l l tend to maintain a constant c o n c e n t r a t i o n d e s p i t e the presence of d i e t a r y d e f i c i e n c i e s . T i s s u e l e v e l s of F l a t i r o n male and non-male bighorn suggest they had adequate l e v e l s of the t r a c e elements copper, z i n c , manganese, and i r o n f o r growth and r e p r o d u c t i o n . T h i s i s a t odds with the sugg e s t i o n from serum l e v e l s t h a t the F l a t i r o n a d u l t females were m a r g i n a l l y d e f i c i e n t i n copper and z i n c . However, based on b a s e l i n e l e v e l s e s t a b l i s h e d f o r domestic sheep l i v e r , i t i s p o s s i b l e the F l a t i r o n bighorn were m a r g i n a l l y d e f i c i e n t i n selenium, which agrees with the serum selenium r e s u l t s . A l f a l f a forages grown i n c e n t r a l B.C. and Washington State have been determined to be inadequate i n selenium with a mean c o n c e n t r a t i o n of 0.047 ppm on a dry weight b a s i s (Cathcart e t a_l. 1980). As with serum t r a c e elements there are no p u b l i s h e d s t u d i e s of t i s s u e t r a c e element l e v e l s i n bighorn sheep. 67 Selenium/vitamin E d e f i c i e n c y i n sheep causes white muscle d i s e a s e ( H i d i r o g l o u 1980) which a f f e c t s domestic lambs between b i r t h and weaning; and l o s s e s may be as high as 65% (see review i n Dubeski 1983). White muscle d i s e a s e i n domestic lambs i s c h a r a c t e r i s e d by f i r s t a r e l u c t a n c e to walk, then a s t i f f n e s s of the hind limbs, and then an arched back stance (Shamberger 1983). The d i s e a s e may a l s o r e s u l t i n m o r t a l i t y from c a r d i a c a r r e s t , but c o r r e c t d i a g n o s i s can be d i f f i c u l t s i n c e v i s i b l e symptoms, such as p a r t i a l p a r a l y s i s of hind and f r o n t l e g s , are not always apparent (Dubeski 1983) . Despite i n t e n s e o b s e r v a t i o n of nursery groups i n 1983 f o r white muscle d i s e a s e , c l i n i c a l symptoms were not observed e i t h e r i n lambs t h a t s u r v i v e d , or i n those t h a t d i e d . T h i s does not, however, preclude the p o s s i b i l i t y of c a r d i a c f a i l u r e i n some of those .lambs which d i e d . The p o s s i b i l i t y of a s i g n i f i c a n t i n t e r a c t i o n between predator a c t i v i t y , and acute c a r d i a c f a i l u r e as a r e s u l t of the s t r e s s of prolonged p u r s u i t cannot be r u l e d out. However, any mineral d e f i c i e n c i e s which r e s u l t e d i n the estimated 70% lamb m o r t a l i t y found i n the F l a t i r o n herd would probably be so severe that c l i n i c a l symptoms would be very apparent. In a d d i t i o n , i f t h i s were the case i t would be expected t h a t blood and t i s s u e l e v e l s would be s i g n i f i c a n t l y lower than those t h a t were found. Disease Incidence The 50% i n c i d e n c e of PI-3 v i r u s i s o l a t e d from the n a s a l 68 swabs was the most i n t e r e s t i n g r e s u l t of d i s e a s e a n a l y s e s . This suggests t h a t approximately h a l f the p o p u l a t i o n may have been s u f f e r i n g from i n f l u e n z a d u r i n g the February and March sampling p e r i o d . However, three of the f o u r lambs which s u r v i v e d the lambing p e r i o d belonged to dams i n f e c t e d with P I - 3 . PI-3 i s a paramyxovirus and common upper r e s p i r a t o r y d i s e a s e of domestic c a t t l e (McLean and Doane 1971) , and domestic sheep (Fischman 1967) . The high i n c i d e n c e of PI-3 i n these otherwise h e a l t h y F l a t i r o n females, and the f a c t t h a t PI-3 i n f e c t i o n had no e f f e c t on r e p r o d u c t i o n , suggests t h a t i t may not be as pathogenic as has p r e v i o u s l y been suspected (Parks e t al_. 1972) . S e r o l o g i c t e s t s on 73 D a l l ' s sheep r e v e a l e d only one p o s i t i v e antibody t i t r e f o r PI-3 (F'oreyt e t a l . 1983) and antibody t i t r e s on 11 p e n i s u l a r d e s e r t bighorn (0_^ c.  cremnobates) were a l l negative f o r PI-3 (Turner and Payson 1982). However, high i n c i d e n c e s of a n t i g e n i c response to PI-3 i n bighorn have been documented i n Colorado and Wyoming (62%, Parks and England 1974) and C a l i f o r n i a (69% to 77%, Deforge e t al. 1982). I t would appear t h a t PI-3 i s a common v i r u s of mountain sheep i n areas where they are i n c o n t a c t w i t h domestic animals. The i n a b i l i t y to i s o l a t e BVD, IBR, adenovirus, Corynebacterium pyrogenes, and P a s t e u r e l l a i n d i c a t e the F l a t i r o n b ighorn are not i n an acute d i s e a s e s i t u a t i o n . P a s t e u r e l l a spp. and Corynebacterium pyogenes have been found i n bighorn which 69 d i e d of b a c t e r i a l bronchiopneumonia and p l e u r i t i s a f t e r a s s o c i a t i o n w i t h domestic sheep (Foreyt and Jessup 1982). The presence of alpha hemolytic S t r e p t o c o c c u s , Corynebacterium spp., F l a v o b a c t e r spp., and Staphylococcus aureus, on n a s a l swabs from F l a t i r o n females i s not thought to be s i g n i f i c a n t t o the assessment of pathogenic d i s e a s e s i n these sheep (Dr. R. Lewis, V e t e r i n a r y P a t h o l o g i s t , p e r s . comm.). Although a l l s i x female sera t e s t e d n e gative f o r the presence of a n t i b o d i e s f o r B r u c e l l a spp. and L e p t o s p i r a spp., these d i s e a s e s have been i s o l a t e d i n other w i l d sheep (Foreyt and Jessup 1982; Foreyt e t a_l. 1983) , and both are h i g h l y pathogenic organisms which are capable of causing l a t e term a b o r t i o n s (Belschner 1965) . Although the sample s i z e of i d e n t i f i e d females which s u c c e s s f u l l y r e ared o f f s p r i n g was low (n=4), they had no obvious advantage i n weights, body c o n d i t i o n s c o r e s , t r a c e m i n e r a l s , or di s e a s e a f f l i c t i o n , compared to those females which l o s t t h e i r lambs. In f a c t , s i x of seven serum minerals measured higher i n three u n s u c c e s s f u l females than the one blood sampled female which s u c c e s s f u l l y reared an o f f s p r i n g (Appendix 4 ) . Unsuccessful females were a l s o h e a v i e r , and had higher body c o n d i t i o n scores than s u c c e s s f u l females, but there was l i t t l e d i f f e r e n c e i n t o t a l l e ngth or h i n d f o o t length (Appendix 4 ) . I t was t h e r e f o r e apparent t h a t n u t r i t i o n and d i s e a s e d i d not a f f e c t lamb s u r v i v a l among the tagged females on F l a t i r o n Mt. i n 1983. 70 P r o d u c t i o n and S u r v i v a l of O f f s p r i n g During the Lambing  P e r i o d Lambing Chronology and P r o d u c t i o n i n Previous Years The lambing p e r i o d on South Slope began e a r l y i n the s p r i n g with the o b s e r v a t i o n of a s i n g l e lamb soon a f t e r m i d - A p r i l . E a r l y dates of o b s e r v a t i o n s of the f i r s t lamb are as f o l l o w s ; A p r i l 22, 1971 ( e s t . born A p r i l 17), A p r i l 18, 1972 (newborn), A p r i l 17, 1983; and A p r i l 18, 1984. Observations f o r 1971 and 1972 are from Webster (unpubl. f i e l d n o t e s ) , and f o r 1983 and 1984 from a r e c o r d book maintained by the Keremeos-Cawston Rod and Gun Club. The temporal p a t t e r n of lamb appearance on South Slope has been i n v e s t i g a t e d p r e v i o u s l y by Blood (1967) and Ramsay (1980). The m a j o r i t y of lambs were born on F l a t i r o n Mountain b e f o r e May 30 i n a l l years except 1960 (Figure 8) . Rapid i n c r e a s e s i n the number of lambs observed o c c u r r e d i n e a r l y June, 1960, and l a t e May, 1961 (Figure 8) . Ramsay (1980) found r a p i d i n c r e a s e s i n the number of lambs observed occurred e a r l i e r than i n the e a r l y 1960's, with most lambs being born i n the f i r s t two weeks of May i n 1978, 1979, and 1980. Lamb numbers d i d not i n c r e a s e as r a p i d l y i n 1982 and 1983 as previous r e s e a r c h e r s had found, but the chronology of b i r t h s was s i m i l a r to the l a t e 1970's, with the m a j o r i t y of lambs being born i n the f i r s t two weeks of May. Maximum number of 20 lambs observed Maximum number of lambs observed F i g u r e 8. P a t t e r n o f o b s e r v a t i o n o f newborn lambs on F l a t i r o n Mounta in i n seven d i f f e r e n t y e a r s . 72 There has been c o n s i d e r a b l e v a r i a t i o n i n the p a t t e r n of lamb s i g h t i n g s on F l a t i r o n Mountain d u r i n g the lambing p e r i o d (Figure 8 ) . T h i s may be due to d i f f e r e n c e s among years i n b i r t h dates, i n the p a t t e r n of female i s o l a t i o n , i n s u r v i v a l of lambs, i n the e f f o r t and a b i l i t y of the observer, or i n some combination of these. In view of the f a c t t h a t some females with lambs stayed away from South Slope f o r up to 60 days i n 1983, the d i f f e r e n c e observed between the e a r l y 1960's and r e c e n t years i s not n e c c e s a r i l y due to a change i n the breeding season. V a r i a t i o n i n the lambing chronology of D a l l ' s sheep between years was small when a c t u a l p a r t u r i t i o n s were observed (Bunnell 1980) . T o t a l numbers of lambs observed range from a h i g h of 49 i n 1967 ( S c h e f f l e r 1973) to a low of 10 i n 1975 and 1977 (Ramsay 19 80 and Table 2) . D e c l i n e s i n the maximum number of a d u l t females observed i n the 1970's corresponded to low lamb:female r a t i o s (Figure 1 ). From 1978 to 1980 lamb:female r a t i o s were over 0.30 but the number of females continued to d e c l i n e . C l a s s i f i c a t i o n counts conducted as p a r t of t h i s study (Table 8) i n d i c a t e an i n c r e a s e i n the number of females i n the p o p u l a t i o n from 1980 to 1982. I f the a d d i t i o n a l number of females i n 1982 were due to r e l a t i v e l y higher lamb p r o d u c t i o n i n 1978 then these should have been censused as an a d d i t i o n a l 14 two year o l d females i n 1980, which was not the case (Table 2). Only i f a l l the estimated 32 female lambs produced i n 1978, 1979 and 1980 s u r v i v e d , and the m o r t a l i t y r a t e of a l l a d u l t females was zero 73 f o r these three y e a r s , c o u l d the r a t e of lamb p r o d u c t i o n e x p l a i n the i n c r e a s e i n a d u l t females from 53 to 81 i n j u s t two y e a r s . One of the i m p l i c a t i o n s of the observed p a t t e r n of female i s o l a t i o n (Figure 5B) i s t h a t to o b t a i n maximum counts of a d u l t females p o p u l a t i o n censuses must be done e i t h e r before or w e l l a f t e r the lambing p e r i o d . I f censuses are done j u s t d u r i n g the lambing p e r i o d from A p r i l 15 to June 15 then the number of females and lambs i n the p o p u l a t i o n may be underestimated. Even i f counts are made i n l a t e June some of the females may not have retu r n e d to the main w i n t e r - s p r i n g range. In 1983, a group of seven females (two tagged), two y e a r l i n g s , and f i v e lambs d i d not r e t u r n u n t i l e a r l y J u l y . T h i s may e x p l a i n why i n some years more y e a r l i n g s were observed than lambs t h a t had been counted the p r e v i o u s year (Ramsay 1980) . P o t e n t i a l F a c t o r s A f f e c t i n g Lamb S u r v i v a l Weather During Lambing The two s e l e c t i v e f o r c e s thought to c o n t r o l the e v o l u t i o n of lambing onset i n mountain sheep are c l i m a t e ( G e i s t 1971), and b i r t h w e i g h t (Bunnell 1980), s i n c e together they determine the e a r l i e s t date t h a t a newborn lamb can s u r v i v e c o l d s t r e s s . Temperatures dropped below f r e e z i n g on three separate occasions at the upper lambing ground weather s t a t i o n d u r i n g the lambing p e r i o d of 1983 (Figure 7) . However, the c l i m a t e of the Ashnola 74 p l a t e a u i s not p a r t i c u l a r l y harsh, when compared to lambing areas at higher e l e v a t i o n s and more n o r t h e r l y l a t i t u d e s (e.g. Hoefs and Cowan 19 79). At the lower e l e v a t i o n s of the South Slope lambing grounds, where dams and newborn lambs were most f r e q u e n t l y observed, the mean minimum temperature d u r i n g the lambing p e r i o d was 5.4° C warmer than higher on the lambing grounds. T h i s o corresponded almost e x a c t l y to the dry a d i a b a t i c lapse r a t e of 1 C per 100m e l e v a t i o n change ( M i l l e r and Thompson 1975). As such the lowest temperature recorded on the lower e l e v a t i o n lambing grounds was +2° C. The use of s h e l t e r , coupled with the m i l d c l i m a t e experienced a t the lower e l e v a t i o n lambing grounds, suggest the. lambs born i n 1983 d i d not experience any thermogregulatory s t r e s s e s t h a t c o u l d not be compensated f o r by c a t a b o l i s m of normal amounts of f a t r e s e r v e s . Though the data was i n c o n c l u s i v e , there was no i n c r e a s e i n the m o r t a l i t y of lambs t h a t was a s s o c i a t e d w i t h inclement weather d u r i n g the lambing p e r i o d , based on a comparison of F i g u r e s 5A and 7. Of the three p e r i o d s i d e n t i f i e d i n F i g u r e 5A when lamb l o s s e s o c c u r r e d , o n l y one was a s s o c i a t e d with inclement weather, the other two o c c u r r i n g d u r i n g p e r i o d s of warm sunny weather. I t should be s t r e s s e d t h a t previous work has demonstrated that thermoregulatory s t r e s s has the g r e a t e s t a f f e c t on neonatal m o r t a l i t y , a p e r i o d t h a t does not appear to be i m p l i c a t e d as the major cause of lamb l o s s e s on F l a t i r o n Mt. 75 S u c k l i n g Behaviour The o v e r a l l mean suc k l e d u r a t i o n of 22 s found i n the F l a t i r o n Mountain herd f a l l s i n between the l e v e l s r e p o r t e d by Shackleton (1973) f o r two p o p u l a t i o n s of c ^ canadensis, and i s s i m i l a r to l e v e l s given by G e i s t (1971), by H o r e j s i (1976), and by Smith and Wishart (1978) , f o r other p o p u l a t i o n s of mountain sheep. G e i s t (1971) f i r s t suggested t h a t suckle d u r a t i o n s were c o r r e l a t e d w i t h lamb p r o d u c t i o n i n mountain sheep p o p u l a t i o n s through the concept of p o p u l a t i o n q u a l i t y . Shackleton (1973) found lamb p r o d u c t i o n p o s i t i v e l y c o r r e l a t e d to la r g e d i f f e r e n c e s i n suc k l e d u r a t i o n between two d i f f e r e n t p o p u l a t i o n s . H o r e j s i (1976) det e c t e d d i f f e r e n c e s i n lamb s u r v i v a l among years i n the same p o p u l a t i o n , t h a t was r e l a t e d to small v a r i a t i o n s i n mean suc k l e d u r a t i o n . However, when mean su c k l e d u r a t i o n s from d i f f e r e n t years and p o p u l a t i o n s was c o r r e l a t e d to the corresponding lamb:female r a t i o s ( G e i s t 1971; Shackleton 1973; H o r e j s i 1976; Smith and Wishart 1978; and t h i s 2 s t u d y ) , there was no s i g n i f i c a n t r e l a t i o n s h i p (r =0.003, n = l l ) . The mean s u c k l e d u r a t i o n of a l l these s t u d i e s was 21 seconds, and the mean lamb:female r a t i o was 0.58. Compared to these other p o p u l a t i o n s , the F l a t i r o n herd had average s u c k l e d u r a t i o n s but l e s s than h a l f t h e i r average lamb p r o d u c t i o n . The s u c k l i n g r a t e of F l a t i r o n lambs was s i m i l a r to t h a t r e p o r t e d i n other p o p u l a t i o n s , d e c l i n i n g from approximately 3 76 bout.h i n one week o l d lambs to l e s s than 1 bout.h i n fo u r week o l d lambs ( G e i s t 1971; Shackleton 1973) . The average bunt r a t e of 0.42 bunts.s 1 of suc k l e d u r a t i o n i n F l a t i r o n lambs i s the same as t h a t determined f o r h i g h l y p r o d u c t i v e p o p u l a t i o n s (Shackleton 1973; H o r e j s i 1976) , but i s lower than t h a t determined f o r Shackleton's low q u a l i t y p o p u l a t i o n . I f the assumption t h a t a high bunt r a t e and s h o r t s u c k l e d u r a t i o n i s a s s o c i a t e d with low milk p r o d u c t i o n i s c o r r e c t (Shackleton 1973), t h i s suggests the milk p r o d u c t i o n of F l a t i r o n females i s g r e a t e r than Shackleton's low q u a l i t y p o p u l a t i o n t h a t had s l i g h t l y higher lamb p r o d u c t i o n . The s u c k l i n g behaviour of F l a t i r o n Mt. lambs, i n terms of s u c k l i n g d u r a t i o n , s u c k l i n g r a t e , and bunt r a t e i s s i m i l a r to t h a t of other p o p u l a t i o n s where lamb p r o d u c t i o n i s h i g h e r . I t does not appear t h a t milk p r o d u c t i o n i s l i m i t i n g the s u r v i v a l of lambs on F l a t i r o n Mountain. The f a c t t h a t F l a t i r o n females had r e l a t i v e l y high l i v e weights and body c o n d i t i o n scores i n l a t e g e s t a t i o n a l s o suggests t h a t l a c t a t i o n p r o d u c t i o n should not be l i m i t i n g lamb s u r v i v a l . P r e d a t i o n There i s l i t t l e doubt t h a t 65 to 70% of the lambs produced each year are s u b j e c t to m o r t a l i t y between p a r t u r i t i o n and three weeks postpartum. T h i s i s evidenced by a high estimated pregnancy r a t e , coupled with a low s u r v i v a l of o f f s p r i n g and the 77 presence of females e x h i b i t i n g a v o c a l i z a t i o n and search behaviour. Observations to determine the t i m i n g of lamb m o r t a l i t y e l i m i n a t e d p r e n a t a l and neonatal m o r t a l i t y , and suggested e a r l y p o s t n a t a l m o r t a l i t y as the reason f o r low lamb p r o d u c t i o n . What i s s t i l l i n doubt i s the cause of t h i s high e a r l y p o s t n a t a l m o r t a l i t y . A v a i l a b l e data have e l i m i n a t e d the l i k e l y h o o d of n u t r i t i o n a l and d i s e a s e s t a t u s of pregnant females, inclement weather d u r i n g lambing, and milk p r o d u c t i o n as estimated by s u c k l i n g behaviour of lambs, as f a c t o r s a f f e c t i n g high e a r l y p o s t n a t a l m o r t a l i t y . Scat contents i n d i c a t e t h a t , depending on the technique used, bighorn lambs e i t h e r c o n s t i t u t e d 24% (volume a n a l y s i s ) or 35% (frequency occurence) of coyotes e a r l y s p r i n g d i e t . A d u l t b ighorn c o n s t i t u t e d e i t h e r 10% (volume a n a l y s i s ) or 18% (frequency occurence) of the coyotes e a r l y s p r i n g d i e t . Percent volume a n a l y s i s tends to underestimate the c o n t r i b u t i o n of l a r g e animals because of t h e i r s m a l l e r s u r f a c e area to mass r a t i o r e l a t i v e to s m a l l e r animals. However, frequency occurence may w e l l overestimate the p r o p o r t i o n of bighorn i n the d i e t of coyotes, s i n c e the remains of one meal may be present i n more than one s c a t . S t a r t i n g with the estimated number of pregnant females on F l a t i r o n Mountain i n 1983 (69) , and s u b t r a c t i n g the maximum count of lambs (20), r e s u l t s i n an estimated 49 lambs t h a t a p p a r e n t l y 78 d i e d between b i r t h and three weeks of age. Using a mean b i r t h w e i g h t of bighorn lambs of 4.0 kg (Bunnell 1982), and the p a t t e r n of l i n e a r weight g a i n r e p o r t e d f o r domestic lambs (Spedding 1965; Peart e t a_l. 1975), a growth r a t e of 0.2 kg.day 1 i s p r e d i c t e d to achieve the mean weight of 5 month o l d lambs gi v e n by Blood e t a l . (1970) and Bunnell (1982) . According to t h i s , bighorn lambs on F l a t i r o n Mountain should weigh approximately 6 kg a t 10 days, 8 kg a t 20 days, and 10 kg at 30 days. Assuming a mean age of 10 days f o r lamb m o r t a l i t i e s , the t o t a l biomass of l o s t lambs i s 294 kg. I t was estimated t h a t a minimum of 15 coyotes i n h a b i t F l a t i r o n Mountain. Messier (1979) reviewed coyote food intake -1 -1 r a t e s , and found i t ranged from 0.06 to 0.17 kg.day .kg body weight. A mean food requirement of 0.12 k g . d a y - 1 . k g - 1 body weight was assumed f o r both h i s c a l c u l a t i o n s and t h i s study. Using the mean weight of a l a r g e sample of B . C . coyotes (11.36 kg, K. Atkinson p e r s . comm.) p r e d i c t s an i n t a k e r a t e of 1.36 kg.day 1 f o r each coyote. Lambs were l o s t from A p r i l 20 to May 20, 1983, a p e r i o d of 30 days, thus the t o t a l estimated food i n t a k e of the 15 coyotes d u r i n g t h i s lambing p e r i o d would be 613 kg. I f coyotes ate a l l the lamb biomass a v a i l a b l e then bighorn lambs should r e p r e s e n t 48% of t h e i r d i e t (294kg/613kg), which i s higher than e i t h e r estimate based on s c a t c o n t e n t s , but c e r t a i n l y i n d i c a t e s t h a t a r e l a t i v e l y small coyote p o p u l a t i o n i n the area c o u l d i n g e s t a l l the lambs estimated to be l o s t each year. 79 Without d i r e c t o b s e r v a t i o n s of p r e d a t i o n , i t i s d i f f i c u l t to determine i f coyotes are a c t u a l l y p r e y i n g on h e a l t h y lambs, or merely scavenging dead and dying lambs. Induc t i v e reasoning leads one to r e j e c t the idea t h a t lambs are born i n a weak or sickened c o n d i t i o n , based on the good c o n d i t i o n of t h e i r dams and t h e i r l a c k of s i g n i f i c a n t d i s e a s e organisms or mineral d e f i c i e n c i e s . A l s o , of those lambs which were born to marked females, none showed any behaviour i n d i c a t i v e of a weakened c o n d i t i o n , i n c l u d i n g those which subsequently d i e d . Bighorn sheep, e s p e c i a l l y lambs, were a major component of the d i e t of pred a t o r s d u r i n g the lambing p e r i o d . Furthermore, based on c i r c u m s t a n t i a l evidence and i n d u c t i v e reasoning, i t appears coyote p r e d a t i o n of otherwise h e a l t h y lambs c o u l d be the source the high e a r l y p o s t n a t a l m o r t a l i t y documented i n t h i s p o p u l a t i o n . Despite much s e a r c h i n g , no c a r c a s s e s of dead lambs were found on F l a t i r o n Mountain, but t h i s i s not s u r p r i s i n g s i n c e predator s c a t s contained l a r g e bone fragments i n d i c a t i n g the e n t i r e lamb was i n g e s t e d . D i r e c t o b s e r v a t i o n of coyote-lamb i n t e r a c t i o n s were not observed, perhaps because the k i l l s were made i n the predawn hours as was the case on a Montana domestic sheep ranch (Henne 1975) . Coyotes have not been r e p o r t e d to be major predator of bighorn o f f s p r i n g b e f o r e , however, seven of 11 coyote s c a t s i n Wyoming con t a i n e d bighorn remains (Thorne 1976 i n 80 Lawson and Johnson 1982) . I s o l a t e d o b s e r v a t i o n s of s u c c e s s f u l p r e d a t i o n by coyotes on b i g h o r n lambs has been r e p o r t e d by Bowen (1978), and Shank (1977). Coyotes have been r e p o r t e d to be major predators of the o f f s p r i n g of other l a r g e ungulates. The f i n d i n g t h a t F l a t i r o n Mountain females l o s e t h e i r lambs up u n t i l t hree weeks of age i s c o n s i s t e n t with mule deer fawn m o r t a l i t i e s due p r i m a r i l y to coyote p r e d a t i o n ( S t e i g e r s and F l i n d e r s 1980; Salwasser 1978). Cook e t a K (1971) used r a d i o t e l e m e t r y , and determined t h a t the high m o r t a l i t y of w h i t e - t a i l e d deer fawns was due to coyote p r e d a t i o n . Coyote p r e d a t i o n was r e s p o n s i b l e f o r the m o r t a l i t y of more than 50% of marked pronghorn fawns when they were between 4 and 57 days o l d ( B a r r e t t 1984) . There have not yet been any i n t e n s i v e s t u d i e s on the e f f e c t of p r e d a t i o n on the s u r v i v a l of bighorn lambs. Predator c o n t r o l on F l a t i r o n Mountain was attempted by the B.C. M i n i s t r y of Environment i n the f i r s t f o u r months of 1973 (B. Webster unpubl.). Two bobcat, 2 coyote, 2 bear, 3 cougar, and 4 lynx were trapped or shot. In a d d i t i o n , approximately 35 to 40 poison b a i t s (1080) were i n g e s t e d , p r i m a r i l y by coyotes based on t r a c k evidence, between March and May, 1973. Despite these e f f o r t s , predator s i g n d u r i n g the lambing p e r i o d i n d i c a t e d not a l l the Canid and F e l i d p r e d a t o r s were k i l l e d , and lamb p r o d u c t i o n was lower than usual with a maximum count of only 12 81 lambs i n 1973. One of the d i f f i c u l t i e s i n e v a l u a t i n g the e f f e c t i v e n e s s of past management p r e s c r i p t i o n s has been the i n a b i l i t y t o show cause and e f f e c t r e l a t i v e to changes i n lamb p r o d u c t i o n . I f p r e d a t i o n was i n f a c t the f a c t o r most l i m i t i n g lamb s u r v i v a l , one might expect e i t h e r a random f l u c t u a t i o n i n y e a r l y predator success, or a c o r r e l a t i o n with predator numbers and a l t e r n a t e prey abundance. Since none of these parameters have ever been measured, the mechanisms behind v a r i a t i o n s i n y e a r l y lamb s u r v i v a l r e l a t i v e to p r e d a t i o n remain unknown. To understand f u l l y those f a c t o r s l i m i t i n g lamb s u r v i v a l , f u t u r e r e s e a r c h should c o n c e n t r a t e on the behaviour and food h a b i t s of the coyote, p a r t i c u l a r l y i t s i n t e r a c t i o n with bighorn lambs i n e a r l y s p r i n g . 82 CONCLUSIONS The f o l l o w i n g c o n c l u s i o n s correspond to the o b j e c t i v e s presented i n the I n t r o d u c t i o n . 1. Low lamb p r o d u c t i o n was not due to a low pregnancy r a t e or a high neonatal m o r t a l i t y , but hig h e a r l y p o s t n a t a l m o r t a l i t y accounted f o r 60 to 70% of lamb l o s s e s . 2a. The n u t r i t i o n a l s t a t u s of F l a t i r o n females, as determined by l i v e w e i g h t and body c o n d i t i o n , was above a l e v e l t h a t would have a f f e c t e d lamb p r o d u c t i o n . 2b. There was no d i f f e r e n c e between F l a t i r o n females t h a t produced v i a b l e lambs and those t h a t l o s t t h e i r lambs i n terms of l i v e w e i g h t , body c o n d i t i o n s c o r e , blood m i n e r a l s , or d i s e a s e a f f l i c t i o n . 3. P r e l i m i n a r y i n f o r m a t i o n i n d i c a t e d no apparent i n c r e a s e i n the m o r t a l i t y of lambs t h a t was a s s o c i a t e d with inclement weather du r i n g the lambing p e r i o d . 83 4. The s u c k l i n g behaviour of F l a t i r o n lambs i n d i c a t e d they d i d not r e c e i v e l e s s milk than p o p u l a t i o n s t h a t had hig h e r lamb p r o d u c t i o n . 5. Bighorn sheep ( e s p e c i a l l y lambs) c o n s t i t u t e d a major component of the d i e t of pr e d a t o r s d u r i n g the lambing p e r i o d . 84 RECOMMENDATIONS Management of C a l i f o r n i a Bighorn i n the Ashnola Food, M i n e r a l and Water Supplementation Winter f e e d i n g should be maintained a t the c u r r e n t l e v e l f o r three reasons. F i r s t l y , to i n s u r e t h a t the c o n d i t i o n of animals remains a t i t s c u r r e n t l e v e l so as to minimize m o r t a l i t y among a d u l t females, and secondly to maintain lamb b i r t h weights a t such a l e v e l t h a t w i l l minimize neonatal m o r t a l i t i e s . T h i r d l y , to t e s t the hypothesis t h a t coyote p r e d a t i o n i s l i m i t i n g lamb p r o d u c t i o n , a l l other f a c t o r s should be h e l d as constant as p o s s i b l e to a v o i d c o n f u s i n g the i n t e r p r e t a t i o n of a response to predator m a n i p u l a t i o n . R e s u l t s i n d i c a t e mineral supplementation should not have a major e f f e c t on lamb s u r v i v a l , however, the p o s s i b i l i t y of a s i g n i f i c a n t i n t e r a c t i o n between a marginal selenium s t a t u s and lamb v u l n e r a b i l i t y to p r e d a t i o n cannot be r u l e d out. Any contemplated mineral supplementation should be undertaken i n c o n s u l t a t i o n w i t h a n u t r i t i o n i s t . Snow pr o v i d e s a source of water w e l l i n t o the growing season, a f t e r which the water content of s p r i n g forages i s high enough to meet bigh o r n requirements. Water l i m i t a t i o n s are probably h i g h e s t i n summer and e a r l y f a l l , when w i n t e r - s p r i n g 85 range forages become d e s i c a t e d . However, t h i s i s a l s o the p e r i o d when the bighorn migrate to a l p i n e areas where delayed phrenology r e s u l t s i n forages of higher water content. Water i s t h e r e f o r e probably not a l i m i t i n g f a c t o r f o r the bighorn of F l a t i r o n Mountain. Range Burning Since p r e p a r t u r a n t females do not appear to be n u t r i t i o n a l l y s t r e s s e d , i t i s u n l i k e l y t h a t range burning w i l l i n c r e a s e lamb p r o d u c t i o n . However, f a l l burning of s o u t h - f a c i n g f o r e s t e d h a b i t a t adjacent to e x i s t i n g grass steppe bighorn ranges may w e l l be able to i n c r e a s e the area of bighorn w i n t e r - s p r i n g h a b i t a t . Thus, i f i n c r e a s e d lamb s u r v i v a l r e s u l t e d i n p o p u l a t i o n growth, t h i s i n c r e a s e d range might a l l o w a higher o v e r a l l c a r r y i n g c a p a c i t y f o r bighorn on F l a t i r o n Mountain. Predator M a n i p u l a t i o n The most common method f o r r e d u c i n g predator pressure on a prey s p e c i e s i s to remove the predators by t r a p p i n g or p o i s o n i n g . Aside from a p o t e n t i a l adverse p u b l i c r e a c t i o n , predator be can c o s t i n e f f e c t i v e . A p o i s o n i n g and t r a p p i n g program on F l a t i r o n Mountain i n 1973 r e q u i r e d much e f f o r t , yet some pr e d a t o r s remained a f t e r the program, and lamb s u r v i v a l d i d not i n c r e a s e (B. Webster unpubl.). Instead of t r a p p i n g , s h o o t i n g , and p o i s o n i n g predators one 86 c o u l d p r o v i d e coyotes with an a t t r a c t i v e food source as an a l t e r n a t i v e to bighorn lambs. Large q u a n t i t i e s of red meat, ob t a i n e d from r o a d - k i l l e d mule deer, p l a c e d i n s t r a t e g i c l o c a t i o n s c o u l d p o t e n t i a l l y draw pre d a t o r s away from the F l a t i r o n Mountain lambing grounds. I f the predators were s a t i a t e d by t h i s a l t e r n a t e food source d u r i n g the 6 week p e r i o d when lambs are v u l n e r a b l e ( A p r i l 15 to May 31) , then they may be l e s s i n c l i n e d to hunt bighorn lambs. Based on my rough estimate of coyote p o p u l a t i o n s i z e and t h e i r food requirement approximately 1000 kg of meat would be r e q u i r e d to cover the 6 week p e r i o d . An i n c r e a s e i n lamb s u r v i v a l of o n l y 10% to 15% i s a l l t h a t i s r e q u i r e d to a l l o w the bighorn p o p u l a t i o n to s t a b i l i z e . One p o t e n t i a l drawback to supplementary f e e d i n g of predators on F l a t i r o n Mountain would be a l l o w i n g the predator p o p u l a t i o n to i n c r e a s e . However, f o r coyotes a t l e a s t , there should be no i n c r e a s e i n t h e i r p o p u l a t i o n , as the c r i t i c a l p e r i o d f o r pup s u r v i v a l occurs i n the f a l l (F. Messier p e r s . comm.), and s p r i n g food supplementation f o r a s h o r t p e r i o d i n the s p r i n g should not i n c r e a s e pup s u r v i v a l . s Future r e s e a r c h e f f o r t s should be d i r e c t e d towards coyote food h a b i t s , behaviour, and i n t e r a c t i o n s with bighorn lambs, before management p r e s c r i p t i o n s aimed at r e d u c i n g coyote numbers are implemented. 87 LITERATURE CITED Adorjan, A.S., and G.B. Kolenosky. 1969. A manual f o r the i d e n t i f i c a t i o n of h a i r s of s e l e c t e d O n t a r i o mammals. Research Report ( W i l d l i f e ) No. 90. O n t a r i o Dept. of Lands and F o r e s t s . 64 pp. A l l e n , J.A. 1912. H i s t o r i c a l and n o m e n c l a t o r i a l notes on North American sheep. B u l l . Am. Mus. of Nat. H i s t . 31:24-25. Alexander, G. 1962. Energy metabolism i n the s t a r v e d new-born lamb. Aust. J . A g r i c . Res. 13:144-164. Alexander, G. and D. W i l l i a m s . 1968. S h i v e r i n g and n o n - s h i v e r i n g thermogenesis d u r i n g summit metabolism i n young lambs. J . P h y s i o l . , London 198:251-276. Bandy, P.J., I.McT. Cowan, W.D. K i t t s , and A.J. Woods. 1956. A method f o r the assessment of the n u t r i t i o n a l s t a t u s of w i l d ungulates. Can. J . Z o o l . 34:48-52. B a r n i c o a t , C.R., A.G. Logan, and A.I. Grant. 1949. M i l k s e c r e t i o n s t u d i e s with New Zealand Romney ewes. Part s I I I and IV. J . A g r i c . S c i . , Camb. 39:237-248. B a r n i c o a t , C.R., P.F. Murray, E.M. Roberts, and G.S. Wilson. 1957. M i l k s e c r e t i o n s t u d i e s with New Zealand Romney ewes. P a r t s V-XI. J . A g r i c . S c i . , Camb. 48:9-35. B a r r e t t , M.W. 1984. Movements, h a b i t a t use, and p r e d a t i o n on pronghorn fawns i n A l b e r t a . J . W i l d l . Manage. 48:542-550. Belsc h n e r , H.G. 1965. Sheep management and d i s e a s e s . A g r i c . and L i v e s t . S e r i e s . Angus and Robertson, Sydney and London. 814 pp. B l i x , A.S. and J.B. Steen. 1979. Temperature r e g u l a t i o n i n newborn p o l a r homeotherms. P h y s i o l . Reviews 59:285-304. Blood, D.A. 1960. P r e l i m i n a r y r e p o r t to the Dept. of F i s h and Game. Min. of Environment f i l e s , P e n t i c t o n , B.C. Blood, D.A. 1961. An e c o l o g i c a l study of C a l i f o r n i a bighorn sheep (Ovis canadensis c a l i f o r n i a n a , Douglas) i n southern B r i t i s h Columbia. M.Sc. T h e s i s . U n i v e r s i t y of B r i t i s h Columbia. 127 pp. Blood, D.A. 1963. Some aspects of behaviour of a bighorn 88 herd. Can. F i e l d Nat. 77:77-94. Blood, D.A. 1967. Food h a b i t s of the Ashnola bighorn sheep herd. Can. F i e l d Nat. 81:23-29. Blood, D.A., D.R. Flook, and W.D. Wishart. 1970. Weights and growth of Rocky Mountain bighorn sheep i n western A l b e r t a . J . W i l d l . Manage. 34:451-455. Bowen, W.D. 1978. S o c i a l o r g a n i z a t i o n of the coyote i n r e l a t i o n to prey s i z e . Ph.D. T h e s i s . U n i v e r s i t y of B r i t i s h Columbia. 230 pp. Brooks, A. 1923. The Rocky Mountain sheep (Ovis canadensis) i n B r i t i s h Columbia. Can. F i e l d Nat. 37:23-25. Buechner, H. K. 1960. The bighorn sheep of the United S t a t e s , i t s p a s t , present, and f u t u r e . W i l d l . Monog. 4. 174 pp. Bunch, T.D., J.W. Bates, P.W. Webb, and E.L. Smith. 1980. Ba s e l i n e p h y s i o l o g i c values i n the d e s e r t b i g h o r n . Desert Bighorn Counc. Trans, pp 46-49. S t . George, Utah. 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 lambing p e r i o d of D a l l ' s sheep. Can. J . Z o o l . 58:1027-1031. B u n n e l l , F.L. 1982. The lambing p e r i o d of mountain sheep: s y n t h e s i s , hypotheses, and t e s t s . Can. J . Z o o l . 60:1-14. B u n n e l l , F.L., and N.A. Olsen. 1981. A g e - s p e c i f i c n a t a l i t y of D a l l ' s sheep. J . Mamm. 62:379-380. Butterworth, M.H., T.R. Houghton, J.C. MaCartney, A.J. P r i o r , C P . Middlemiss, and D.E. Edmond. 1968. Some ob s e r v a t i o n s on the l a c t a t i o n of B l a c k f a c e ewes and the growth of lambs: the composition and y i e l d of milk . J . A g r i c . S c i . , Camb. 70:203-207. Butterworth, M.H. and T.W.D. B l o r e . 1969. The l a c t a t i o n of P e r s i a n Blackhead ewes and the growth of lambs. J . A g r i c . S c i . , Camb. 73:133-137. C a t h c a r t , E.B., J.A. S h e l f o r d , and R.G. Peterson. 1980. Mineral analyses of d a i r y c a t t l e feed i n the upper F r a s e r V a l l e y of B r i t i s h Columbia. Can. J . Anim. S c i . 60:177-183. Chappel, R.W., and R.J. Hudson. 1978. Winter b i o e n e r g e t i c s of Rocky Mountain bighorn sheep. Can. J . Z o o l . 56:2388-2393. Cohen, R.D.H. 1980. Phosphorus i n rangeland ruminant n u t r i t i o n : A review. L i v e s t . Prod. S c i . 7:25-37. 89 Cook, R.S., M. White, D.O. T r a i n e r , and W.C. Glazner. 1971. M o r t a l i t y of young w h i t e - t a i l e d deer fawns i n south Texas. J . W i l d l . Manage. 35:47-56. Cowan, I.McT. 1951. Report to Dept. of F i s h and Game. Min. of Environment f i l e s , P e n t i c t o n , B.C. Cowan, I.McT., and C.J. Guiguet. 1956. The mammals of B r i t i s h Columbia. B r i t i s h Columbia P r o v i n c i a l Museum, Handbook No. 11. V i c t o r i a , B r i t i s h Columbia. 414 pp. Deas, D.W. 1977. Pregnancy d i a g n o s i s i n the ewe by an u l t r a s o n i c r e c t a l probe. Vet. Rec. 101:113-115. Deforge, J.R., and J.E. S c o t t . 1982. E c o l o g i c a l i n v e s t i g a t i o n s i n t o h i g h lamb m o r t a l i t y of d e s e r t bighorn sheep i n the Santa Rosa Mountains, C a l i f o r n i a . Desert Bighorn C o u n c i l T r a n s a c t i o n s , pp 65-76. Borrego S p r i n g s , C a l i f . Deforge, J.R., Jessup, D.A., Jenner, C.W., and J.E. S c o t t . 1982. Disease i n v e s t i g a t i o n i n t o high lamb m o r t a l i t y of d e s e r t b i g h o r n i n the Santa Rosa Mountains, C a l i f o r n i a . Desert Bighorn C o u n c i l T r a n s a c t i o n s , pp 76-81. Borrego S p r i n g s , C a l i f . Demarchi, R.A. 1965. An e c o l o g i c a l study of the Ashnola b i g h o r n winter ranges. M.Sc. T h e s i s . U n i v e r s i t y of B r i t i s h Columbia. 103 pp. Demarchi, R.A. 1968. Chemical composition of bighorn winter f o r a g e s . J . Range Manage. 21:385-387. Dubeski, P.L. 1983. Iron and selenium supplementation of sheep. M.Sc. T h e s i s . U n i v e r s i t y of B r i t i s h Columbia. 160 pp. E c c l e s , T.R. and D.M. Shackleton. 1979. Recent r e c o r d s of twinning i n North American mountain sheep. J . W i l d l . Manage. 43:974-976. F a i r a i z l , S.D. 1980. P o p u l a t i o n c h a r a c t e r i s t i c s of t r a n s p l a n t e d C a l i f o r n i a bighorn sheep i n western North Dakota. Bienn. Symp. North. Wild Sheep and Goat Counc. 2:70-89. F i n g e r , S.E., L. B r i s b i n J r . , and M.H. Smith. 1981. Kidney f a t as a p r e d i c t o r of body c o n d i t i o n i n w h i t e - t a i l e d deer. J . W i l d l . Manage. 45:964-968. Fischman, H.R. 1967. Epidemiology of p a r a i n f l u e n z a - 3 i n f e c t i o n i n sheep. Am. J . E p i d e m i o l . 85:272-281. 90 Forbes, J.M. 1969. A note on the v o l u n t a r y feed i n t a k e of l a c t a t i n g ewes, t h e i r milk y i e l d , and the growth r a t e of t h e i r lambs. Anim. Prod. 11:263-266. F o r e y t , W.J., and D.A. Jessup. 1982. F a t a l pneumonia of bighorn sheep f o l l o w i n g a s s o c i a t i o n with domestic sheep. J . W i l d l . D i s . 18:163-168. Fo r e y t , W.J., T.C. Smith, J.F. Evermann, and W.E. Heimer. 1983. Hematologic, serum chemistry and s e r o l o g i c v a l u e s of D a l l ' s sheep (Ovis d a l l i d a l l i ) i n A l a s k a . J . W i l d l . D i s . 136-139. Franzmann, A.W. 1971. P h y s i o l o g i c values of stone sheep. J . W i l d l . D i s . 7:139-141. Franzmann, A.W. 1972. Environmental sources of v a r i a t i o n of big h o r n sheep p h y s i o l o g i c v a l u e s . J . W i l d l . Manage. 36:924-932. Franzmann, A.W. and E.T. Thorne. 1970. P h y s i o l o g i c v a l u e s i n w i l d bighorn sheep (Ovis canadensis canadensis) a t capture, a f t e r h a n d l i n g , and a f t e r c a p t i v i t y . J . Am. Vet. Med. Assoc. 157:647-650. G a r e l , J.M. 1983. P a r a t h y r o i d hormone, c a l c i t o n i n and mineral metabolism i n the mammalian f e t u s and neonate. Chapter 5, In " P e r i n a t a l Calcium and Phosphorus Metabolism" H o l i k , M.F., T.K. Gray, and C.S. Anast (eds). E l s e v i e r Science P u b l i s h e r s B.V., Amsterdam and New York. G e i s t , V. 1971. Mountain sheep - A study i n behavior and e v o l u t i o n . U n i v e r s i t y of Chicago Press, Chicago. 383 pp. Harcombe, A. and R. Kowall 1982. Keremeos f o r e s t encroachment. Working r e p o r t 1982-06-15. Resource A n a l y s i s Branch, M i n i s t r y of Environment. Kelowna, B.C.. Harper, F.E. 1969. E f f e c t s of c e r t a i n c l i m a t i c f a c t o r s on the -p r o d u c t i v i t y and a v a i l a b i l i t y of forages on the Ashnola big h o r n winter ranges. M.Sc. T h e s i s . U n i v e r s i t y of B r i t i s h Columbia. 112 pp. Harper, W.L. 1980. A comparison of p o p u l a t i o n q u a l i t y among three herds of C a l i f o r n i a bighorn sheep i n the Okanagan Region. Unpublished r e p o r t . Min. of Environment, P e n t i c t o n , B.C.. 95 pp. Harper, W.L. and R.D.H. Cohen. In p r e s s . Accuracy of Doppler 91 u l t r a s o u n d i n d i a g n o s i n g pregnancy i n bighorn sheep. J . W i l d l . Manage. Hart, J.S., 0. Heroux, W.H. C o t t l e , and C A . M i l l s . 1961. The i n f l u e n c e of c l i m a t e on metabolic and thermal responses of i n f a n t c a r i b o u . Can. J . Z o o l . 39:845-856. Hebert, D.M. 1972. Forage and serum phosphorus val u e s f o r bighorn sheep. J . Range Manage. 25:292-296. Hebert, D.M. 1978. Blood chemistry as an i n d i c a t o r of n u t r i t i o n a l c o n d i t i o n i n bighorn sheep. Bienn. Symp. North. Wild Sheep and Goat Counc. 1:365-387. Henne, D.R. 1975. Domestic sheep m o r t a l i t y on a western Montana ranch. In "Proceedings of the 1975 Predator Symposium". P h i l l i p s , R.L. and C Jonkel (eds) U n i v e r s i t y of Montana, M i s s o u l a , pp 133-146. Hickey, W.O. 1976. Bighorn sheep ecology. P r o j e c t W-160-R-3. Job progress r e p o r t . Idaho Dept. of F i s h and Game. Sept. 1976. H i d i r o g l o u , M. 1980. Trace elements i n the f e t a l and neonate ruminant: A review. Can. Vet. J . 21:328-335. Hil l m a n , L.S. 1983. M i n e r a l i z a t i o n and l a t e mineral homeostasis i n i n f a n t s . Chapter 15. In " P e r i n a t a l Calcium and Phosphorus Metabolism" H o l i k , M.F., T.K. Gray, and C.S. Anast (eds). E l s e v i e r Science P u b l i s h e r s B.V., Amsterdam and New York. Hoefs, M. and I. McT. Cowan. 1979. E c o l o g i c a l i n v e s t i g a t i o n of a p o p u l a t i o n of D a l l sheep (Ovis d a l l i d a l l i , N e l s o n ) . S y e s i s 12 (Suppl. 1). 81 pp. H o r e s j i , B.L. 1976. S u c k l i n g and f e e d i n g behavior i n r e l a t i o n to lamb s u r v i v a l i n bighorn sheep (Ovis canadensis  canadensis, Shaw). Ph.D. T h e s i s . U n i v e r s i t y of C a l g a r y . 265 pp. Hulet, C.V. 1973. Determining f e t a l numbers i n pregnant ewes. J . Anim. S c i . 36:325-330. Lawson, B., and R. Johnson. 1982. Mountain sheep. Chapter 52. In "Wild mammals of North America - b i o l o g y , management, and economics". Chapman, J.A., and G.A. Feldhamer (eds). John Hopkins U n i v e r s i t y Press, B a l t imore and London, pp 1036-1055. Leathern, J.H. 1966. N u t r i t i o n a l e f f e c t s on hormone p r o d u c t i o n . 92 J . Anim. S c i . , Suppl. 25:68-82. Lent, P.C. 1974. Moth e r - i n f a n t r e l a t i o n s h i p s i n ungulates. In "The behaviour of ungulates and i t s r e l a t i o n to management". G e i s t , V and F. Walther (eds). I n t e r n a t i o n a l Union f o r Cons e r v a t i o n of Nature and Na t u r a l Resources, Morges, S w i t z e r l a n d , pp 14-55. L i n d a h l , I.L. 1971. Pregnancy d i a g n o s i s i n the ewe by i n t r a r e c t a l Doppler. J . Anim. S c i . 32:922-925. McDonald, S.E., S.R. Pa u l , and T.O. Bunch. 1981. P h y s i o l o g i c and hematologic v a l u e s i n Nelson d e s e r t bighorn sheep. J . W i l d l . D i s . 17:131-134. McLean, A.M. and F.W. Doane. 1971. The morphogenesis and cytopath o l o g y of bovine p a r a i n f l u e n z a type 3 v i r u s . J . Gen. V i r o l . 12:271-279. M a r s h a l l , M.M., J.G. Songer, C.J. C h i l e l l i , and J.C. deVos. 1983. I s o l a t i o n s of a e r o b i c b a c t e r i s from w i l d d e s e r t bi g h o r n sheep (Ovis canadensis n e l s o n i and 0_^  c.•  mexicana) i n A r i z o n a . J . W i l d l . Dis 19:98-100. Messier, F. 1979. Etude de l a p r e d a t i o n du c e r f de V i r g i n e par le coyote dans l e ravage d'Armstrong, Beauce sud. M.Sc. T h e s i s . U n i v e r s i t y of L a v a l , Quebec. 164 pp. M i l l e r , A., and J.C. Thompson. 1975. Elements of Meteorology. C.E. M e r r i l l P u b l. Co., Columbus, Ohio. Moore, T.D., Spence, L.E., and C.E. Dugnolle. 1974. I d e n t i f i c a t i o n of the d o r s a l guard h a i r s of some mammals of Wyoming. B u l l e t i n No. 14, Wyoming Game and F i s h Dept., Cheyenne, Wyoming. Morrison, D.C. 1972. H a b i t a t u t i l i z a t i o n by mule deer i n r e l a t i o n to c a t t l e and C a l i f o r n i a bighorn sheep i n the Ashnola R i v e r V a l l e y , B r i t i s h Columbia. M.Sc. T h e s i s , U n i v e r s i t y of B r i t i s h Columbia. Munro,J. 1962. A study of the milk y i e l d of three s t r a i n s of S c o t t i s h B l a c k f a c e ewes i n two environments. Anim. Prod. 4:203-213. N a t i o n a l Research C o u n c i l . 1975. N u t r i e n t requirements of sheep. N a t i o n a l Research C o u n c i l , Washington, D.C. 72 pp. Nalbandov, A.V. 1976. Reproductive p h y s i o l o g y of mammals and b i r d s . 3rd ed. W.H. Freeman and Co., San 93 F r a n s i s c o . 334pp. N i c h o l s , L. 1978. D a l l sheep r e p r o d u c t i o n . J . W i l d l . Manage. 42:570-580. Owen, J.B. 1957. A study of the l a c t a t i o n and growth of H i l l sheep. J . A g r i c . S c i . , Camb. 48:387-412. Parks, J.B., G. Post, T. Thorne, and P. Nash. 1972. Pa r a i n f l u e n z a - 3 v i r u s i n f e c t i o n i n Rocky Mountain bighorn sheep. J . Am. Vet. Med. Assoc. 161:669-672. Parks, J.B., and J . J . England. 1974. A s e r o l o g i c a l survey f o r s e l e c t e d v i r a l i n f e c t i o n s of Rocky Mountain bighorn sheep. J . W i l d l . D i s . 10:107-110. Peart, J.N. 1967. The e f f e c t of d i f f e r e n t l e v e l s of n u t r i t i o n ' d u r i n g l a t e pregnancy on the subsequent milk p r o d u c t i o n of B l a c k f a c e ewes and on the growth of t h e i r lambs. J . A g r i c . S c i . , Camb. 68:365-371. Pea r t , J.N. 1968. Some e f f e c t s of l i v e weight and body c o n d i t i o n on the milk p r o d u c t i o n of B l a c k f a c e ewes. J . A g r i c . S c i . , Camb. 70:331-338. Peart, J.N., J.M. Doney, and A.J. MacDonald. 1975. The i n f l u e n c e of lamb genotype on the milk p r o d u c t i o n of B l a c k f a c e ewes. J . A g r i c . S c i . , Camb. 84:313-316. Peterson, R., and A. B o t t r e l l . 1978. Normal metabolic p r o f i l e s of lamb and a d u l t C a l i f o r n i a bighorn sheep. Bienn. Symp. North. Wild Sheep.and Goat Counc. 1:342-349. P u i s , R. 1981. V e t e r i n a r y t r a c e mineral d e f i c i e n c y and t o x i c i t y i n f o r m a t i o n . P u b l i c a t i o n 5139, Information S e r v i c e s , A g r i c u l t u r e Canada, Ottawa, O n t a r i o . 101 pp. Ramsay, M.A. 1980. Aspects of the r e p r o d u c t i v e ecology of C a l i f o r n i a bighron sheep on the Ashnola p l a t e a u r e g i o n of B r i t i s h Columbia. M.Sc. T h e s i s . Simon F r a s e r U n i v e r s i t y , Burnaby, B.C.. 103 pp. Romesburg, H.C. 1981. W i l d l i f e s c i e n c e : G a i n i n g r e l i a b l e knowledge. J . W i l d l . Manage. 45:293-313. R u s s e l , A.J.F., J.M. Doney, and R.L. Reid. 1967. The use of bioc h e m i c a l parameters i n c o n t r o l l i n g n u t r i t i o n a l s t a t e i n pregnant ewes, and the e f f e c t of undernourishment duri n g pregnancy on lamb b i r t h - w e i g h t . J . A g r i c . S c i . , Camb. 68:351-358. 94 R u s s e l , A.J.F., J.M. Doney, and R.G. Gunn. 1969. S u b j e c t i v e assessment of body f a t i n l i v e sheep. J . A g r i c . S c i . , Camb. 72:451-454. Salwasser, H., S.A. H o l l , and G.A. A s h c r a f t . 1978. Fawn pr o d u c t i o n and s u r v i v a l i n the North Kings R i v e r deer herd. C a l i f . F i s h and Game 64:38-52. S c h e f f l e r , E.G. 1973. An a p p r a i s a l of ungulate h a b i t a t s i n the Ashnola resource management u n i t . M.Sc. T h e s i s . U n i v e r s i t y of B r i t i s h Columbia. 196 pp. Shackleton, D.M. 1973. Po p u l a t i o n q u a l i t y and bighorn sheep (Ovis canadensis canadensis, Shaw). Ph.D. T h e s i s . U n i v e r s i t y of Ca l g a r y . 227 pp. Shackleton, D.M., R.G. Peterson, J . Haywood, and A. B o t t r e l l . 1984. G e s t a t i o n p e r i o d i n Ovis canadensis. J . Mamm. 65:337-338. Shamberger, R.J. 1983. Bio c h e m i s t r y of selenium. Plenum P r e s s . New York and London. pp 38-40. Shank, C.C. 19 77. Cooperative defence by bighorn sheep. J . Mamm. 58: 243-244. S i l v e r , R.S. 1971. Probable f a c t o r s a f f e c t i n g the i n c r e a s e of C a l i f o r n i a bighorn sheep (Ovis canadensis  c a l i f o r n i a n a , Douglas) p o p u l a t i o n s . B.Sc. T h e s i s . F o r e s t r y 495. U n i v e r s i t y of B r i t i s h Columbia. Simmons, N.M., M.B. Bayer, and L.O. Sinkey. 1984. Demography of D a l l ' s sheep i n the Mackenzie Mountains, Northwest T e r r i t o r i e s . J . W i l d l . Manage. 48:156-162. Smith, K.G., and W.D. Wishart. 1978. Furthe r o b s e r v a t i o n s of bighorn sheep non-trophy seasons i n A l b e r t a and t h e i r management i m p l i c a t i o n s . Bienn. Symp. North. Wild Sheep and Goat Counc. 1:52-74. Smith, N.S. 1970. A p p r a i s a l of c o n d i t i o n e s t i m a t i o n methods f o r E a s t A f r i c a n ungulates. E. A f r . W i l d l . J . 8:123-130. Sp a l d i n g , D.J. 1966. Twinning i n bighorn sheep. J . W i l d l . Manage. 30:207. Spedding, C.R.W. 1965. Sheep p r o d u c t i o n and g r a z i n g managment. Chapter V. The lamb - i t s growth and development. B a i l l i e r e , T i n d a l l and Cox, London, pp 101-140. Spraker, T.R. and C P . H i b l e r . 1982. An overview of the 95 c l i n i c a l s i g n s , gross and h i s t o l o g i c a l l e s i o n s of the pneumonia complex of b i g h o r n sheep. Bienn. Symp. North. Wild Sheep and Goat Counc. 3:163-172. S t e i g e r s , W.D., and J.T. F l i n d e r s . 1980. M o r t a l i t y and movements of mule deer fawns i n Washington. J . W i l d l . Manage. 44:381-388. Sugden, L.G. 1961. The C a l i f o r n i a bighorn i n B r i t i s h Columbia with p a r t i c u l a r r e f e r e n c e to the Churn Creek herd. B r i t i s h Columbia Department of R e c r e a t i o n and C o n s e r v a t i o n . 58 pp. T a y l o r , R.L. and B. MacBryde. 1977. V a s c u l a r p l a n t s of B r i t i s h Columbia. Tech. B u l l . No. 4. U n i v e r s i t y of B r i t i s h Columbia P r e s s , Vancouver. 754 pp. Thomson, A.M., and W. Thomson. 1949. Lambing i n r e l a t i o n to d i e t i n the pregnant ewe. B r i t . J . Nutr. 2:290-305. Thomson, A.M., and W. Thomson. 1953. E f f e c t of d i e t on milk y i e l d of the ewe and the growth of her lamb. B r i t . J . Nut. 7:263-274. Thorne, E.T. 1976. The s t a t u s , m o r t a l i t y and response to management of the Whiskey B a s i n bighorn sheep herd. Fed. A i d i n W i l d l . R e s tor. P r o j . FW-3-R-22, work pl a n 3, job 15W. Wyoming Game and F i s h Dept. Thorne, E.T., R.E. Dean, and W.G. Hepworth. 1976. N u t r i t i o n d u r i n g g e s t a t i o n i n r e l a t i o n to s u c c e s s f u l r e p r o d u c t i o n i n e l k . J . W i l d l . Manage. 40:330-335. Trapp, M.J., and A.L. S l y t e r . 1983. Pregnancy d i a g n o s i s i n the ewe. J . Anim. S c i . 57:1-5. Turner, J . C , and J.B. Payson. 1982. Prevalence of a n t i b o d i e s of s e l e c t e d i n f e c t i o u s d i s e a s e agents i n the p e n i n s u l a r d e s e r t bighorn sheep (Ovis canadensis cremnobates) of the Santa Rosa Mountains, C a l i f o r n i a ! J . W i l d l . D i s . 18:243-245. Underwood, E . J . 1977. Trace elements i n human and animal n u t r i t i o n . 4th ed. Academic Press, New York. Valdez, R. 1976. Fecundity of w i l d sheep (Ovis o r i e n t a l i s ) i n I r a n . J . Mammal. 57:762-763. Verme, L . J . 1965. Reproduction s t u d i e s on penned w h i t e - t a i l e d deer. J . W i l d l . Manage. 29:74-79. 96 Verme, L . J . 1977. Assessment of n a t a l m o r t a l i t y i n upper Michigan deer. J . W i l d l . Manage. 41:700-708. Wallace, L.R. 1948. The growth of lambs before and a f t e r b i r t h i n r e l a t i o n to the l e v e l of n u t r i t i o n . P a r t s I and I I I . J . A g r i c . S c i . , Camb. 38:93-153, 367-401. Wani, G.M. and K.L. Sahni. 1981. U l t r a s o n i c pregnancy d i a g n o s i s i n ewes under t r o p i c a l f i e l d c o n d i t i o n s . Indian J . Anim. S c i . 51:194-197. Webster, A.J.F. 1976. E f f e c t s of c o l d on energy metabolism of sheep. Chapter 1, S e c t i o n 8b i n "Progress i n Biometeorology". Tromp, S.W. and J . J . Bouma (eds). Swets and Z e i t l i n g e r B.V., Amsterdam, pp. 218-226. Woodard, T.N., G u t i e r r e z , R.J., and W.H. Ru t h e r f o r d . 1974. Bighorn lamb p r o d u c t i o n , s u r v i v a l , and m o r t a l i t y i n s o u t h - c e n t r a l Colorado. J . W i l d l . Manage. 38:771-774. Woolf, A. and D.C. K r a d e l . 1970. Hematological v a l u e s of c a p t i v e Rocky Mountain bighorn sheep. J . W i l d l . D i s . 6:67-68. 97 Appendix I. Paper submitted to the Jo u r n a l of W i l d l i f e Management ( i n p r e s s ) . ACCURACY OF DOPPLER ULTRASOUND IN DIAGNOSING PREGNANCY IN BIGHORN SBEEP Keywords: Doppler, u l t r a s o u n d , pregnancy d i a g n o s i s , bighorn sheep, Ovis canadensis. W.L. Harper and R.D.H. Cohen ^"Department of Animal Science U n i v e r s i t y of B r i t i s h Columbia Vancouver, B.C., V6T 2A2, Canada and Department of Animal and P o u l t r y Science U n i v e r s i t y " o f Saskatchewan Saskatoon, Saskatchewan, S7N 0W0, Canada 98 A r e l i a b l e estimate of the p r o p o r t i o n of females t h a t s u c c e s s f u l l y conceive i s an important p i e c e of i n f o r m a t i o n t h a t i s r e q u i r e d to f u l l y understand the p o p u l a t i o n dynamics of a s p e c i e s . T h i s i s e s p e c i a l l y important when the p o p u l a t i o n of o f f s p r i n g i s low. These data are g e n e r a l l y u n a v a i l a b l e f o r w i l d l i f e p o p u l a t i o n s so female p r o d u c t i o n estimates u s u a l l y are based upon counts of o f f s p r i n g f o r the year. These counts o f t e n are made a f t e r the e a r l y p o s t n a t a l p e r i o d d u r i n g which s i g n i f i c a n t m o r t a l i t y can take p l a c e . In a d d i t i o n , counts of o f f s p r i n g g i v e no i n d i c a t i o n of p r e n a t a l r e p r o d u c t i v e f a i l u r e s . The main c o n s t r a i n t i n e s t i m a t i n g pregnancy r a t e s has been one of methodology. E i t h e r the techniques are d i f f i c u l t to use and s u b j e c t to e r r o r when a s i n g l e sample i s obta i n e d , or they r e q u i r e s a c r i f i c i n g l a r g e numbers of females f o r r e l i a b l e estimates to be made by autopsy. Many techniques have been developed to diagnose pregnancy i n domestic animals. These i n c l u d e hormonal assays, r e c t a l p a l p a t i o n , radiography, v a g i n a l b i o p s y , laparotomy, and ul t r a s o u n d (Memon and Ott 1980). Of'these' techniques, some have been used w i t h w i l d s p e c i e s ; ' f o r example progesterone assay (Ramsay and S a d l e i r 1979; Whitehead and McEwan 1980; Rehbinder et a l . 1981), r e c t a l p a l p a t i o n ( F o l l i s and S p i l l e t 1974), u l t r a s o u n d ( B a r r e t t 1981; Smith and Lindzey 1982) , and laparotomy (Turner 1983) . Assaying f o r hormones i s r e l a t i v e l y expensive and 99 does not g i v e immediate r e s u l t s , and s i n c e the l e v e l s of c i r c u l a t i n g progestrone vary e r r a t i c a l l y between i n d i v i d u a l s , as w e l l as through g e s t a t i o n , t h i s technique can be s u b j e c t to m i s i n t e r p r e t a t i o n (Whitehead and McEwan 1980). R e c t a l p a l p a t i o n i s s u i t a b l e o n l y f o r l a r g e r mammals and r e q u i r e s e x t e n s i v e experience f o r accurate r e s u l t s . Memon and Ott (1980), reviewed the techniques a v a i l a b l e f o r pregnancy d i a g n o s i s i n domestic sheep and goats, and concluded t h a t Doppler u l t r a s o u n d was the most accurate and r e l i a b l e method. There are two types of u l t r a s o u n d d e v i c e s c u r r e n t l y a v a i l a b l e f o r d i a g n o s i n g pregnancy i n w i l d animals: the Doppler, and the pulse-echo. E x t e r n a l Doppler ultasound was 92% accurate i n determining pregnancy i n a l a r g e sample of domestic ewes, under f i e l d c o n d i t i o n s (Wani and Sahni 1981) . Pulse-echo u l t r a s o u n d , (a l s o known as amplitude depth or A-scan), has been used to r e l i a b l y diagnose pregnancy i n mule deer (Odocoileus  hemionus) , but the accuracy of t h i s method decreases a f t e r m i d - g e s t a t i o n (Smith and Lindzey 1982) . The o b j e c t i v e s of t h i s study were to e v a l u a t e the accuracy of Doppler u l t r a s o u n d f o r d i a g n o s i n g pregnancy i n c a p t i v e bighorn sheep (Ovis c a n a d e n s i s ) , and to compare these data w i t h those from domestic sheep, with the u l t i m a t e goal being the use of t h i s technique on f r e e - r a n g i n g bighorns. 100 METHODS EQUIPMENT A p o r t a b l e (0.61 kg) Medata Doppler Ultrasound Pregnancy De t e c t o r , (Medata Systems L t d . , The Parade, Pagham, West Sussex, England, P021 4WT) , was used on 23 bighorn and 59 domestic sheep. T h i s d e v i c e operates as f o l l o w s : an e x t e r n a l t r a n s d u c e r , c o n s i s t i n g of t r a n s m i t t i n g and r e c e i v i n g p i e z o e l e c t r i c c r y s t a l s , i s p l a c e d i n c o n t a c t with the s k i n . A t h i n l a y e r of mineral o i l or V a s e l i n e between the transducer and the s k i n serves to exclude a i r which w i l l b l o c k the t r a n s m i s s i o n of sound waves. A continuous s i n u s o i d a l wave of low power u l t r a s o u n d (2 MHz; -2 lOmW.cm ) i s d i r e c t e d i n t o the body c a v i t y from the t r a n s m i t t i n g c r y s t a l . When the sound wave s t r i k e s v a r i o u s t i s s u e s i t i s r e f l e c t e d back to the r e c e i v i n g c r y s t a l . The Doppler s h i f t p r i n c i p l e (Rose and Goldberg 1979) i s used to d e t e c t t i s s u e movements a s s o c i a t e d with pregnancy. Depending on the d i r e c t i o n of t i s s u e movement, the r e f l e c t e d wave i s d i s p l a c e d to a higher or lower frequency, and once r e c e i v e d i s analysed e l e c t r o n i c a l l y , and the r e s u l t a n t s i g n a l broadcast on a speaker system. In the Medata Pregnancy Detector the e l e c t r o n i c s and the speakers are p a r t of the headphone apparatus, and operate on a 12 v o l t t r a n s i s t o r b a t t e r y . 101 ANIMALS AND MEASUREMENTS The sample of bighorn females was c a p t i v e and came from two l o c a t i o n s ; the Okanagan Game Farm, P e n t i c t o n , B.C. (n=20, O.c.  c a l i f o r n i a n a ) , and the Animal Care F a c i l i t y , U n i v e r s i t y of B r i t i s h Columbia, Vancouver, B.C. (n=3, O.c. c a n a d e n s i s ) . Bighorn females were t e s t e d between 110 and 150 days g e s t a t i o n ; f u l l term i s 174 days (Shackleton e t a_l. 1984) . I n d i v i d u a l s were i d e n t i f i e d , and the accuracy of pregnancy d i a g n o s i s was confirmed at lambing. The sample of domestic ewes came from a r e s e a r c h herd at the Dept. of Animal Science, U n i v e r s i t y of B r i t i s h Columbia (n=9), and a commercial herd a t Al d e r g r o v e , B.C. (n=50). The ewes from the U n i v e r s i t y herd were t e s t e d between 90 and 120 days of g e s t a t i o n (term = 145 d a y s ) . F o r t y one of the ewes from the commercial farm were examined between 74 and 94 days of g e s t a t i o n and another 9 ewes were between 118 days and term. The e x t e r n a l transducer head was placed on the abdomen both a n t e r i o r and p o s t e r i o r to the t e a t s and between 5 and 15 cm. e i t h e r s i d e of m i d - l i n e . I t was then manipulated to scan the abdominal c a v i t y i n search of the sounds c h a r a c t e r i s t i c of pregnancy. I d e n t i f i c a t i o n of one or more of the c h a r a c t e r i s t i c sounds generated by the u t e r i n e a r t e r y , p l a c e n t a l c i r c u l a t i o n , f e t a l movement, u m b i l i c a l a r t e r y , or f e t a l h e a r t , was considered p o s i t i v e evidence of pregnancy. I f none of the c h a r a c t e r i s t i c sounds was de t e c t e d w i t h i n 5-10 minutes, the animal was diagnosed 102 as nonpregnant. P o s i t i v e d i a g n o s i s of pregnancy o f t e n took as l i t t l e as 30 seconds, e s p e c i a l l y with females i n the l a s t t h i r d of g e s t a t i o n . The o n l y other sounds which c o u l d be de t e c t e d were the p e r i s t a l t i c movement i n the lower i n t e s t i n e s , and the i n t e r f e r e n c e a s s o c i a t e d with f r i c t i o n between the transducer and the s u b j e c t . There was no d i f f i c u l t y i n r e c o g n i s i n g the d i f f e r e n c e between these sounds and those a s s o c i a t e d with pregnancy. Parentage of lambs was determined from lambing records f o r the domestic herds and the c a p t i v e bighorn a t the U n i v e r s i t y of B r i t i s h Columbia. S u c c e s s f u l s u c k l i n g of a lamb confirmed parentage i n the Okanagan Game Farm bighorn herd. RESULTS PREGNANCY DETERMINATION OF BIGHORN A l l 3 female bighorn a t the U n i v e r s i t y of B r i t i s h Columbia were diagnosed pregnant i n A p r i l , 1982 and produced lambs i n June (Table 1 ) . E i g h t of the 11 c a p t i v e bighorn females at the Okanagan Game Farm r e s e a r c h herd were diagnosed pregnant i n A p r i l , 1982 (Table 1 ) . These sheep lambed around the l a s t week i n May and 7 lambs were observed on June 13, 1982. When the herd was 103 r e c a p t u r e d i n June a l l 8 females t h a t were diagnosed pregnant were a p p a r e n t l y l a c t a t i n g , based on the swollen c o n d i t i o n of the mammary glands. However, o b s e r v a t i o n of the herd r e v e a l e d t h a t one of the animals which had been diagnosed pregnant, and had a swollen udder, was not s u c k l i n g a lamb. L a t e r t h a t year the remains of a lamb were d i s c o v e r e d . The lamb had been k i l l e d or scavenged by coyotes. These remains were assumed to be t h a t of the lamb from the aforementioned ewe. The f o l l o w i n g year 9 of the 11 bighorn ewes at the Okanagan Game Farm were captured and t e s t e d with Doppler u l t r a s o u n d on A p r i l 12, 1983. E i g h t of these were diagnosed pregnant (Table 1). By June 12, there were 7 lambs and by J u l y 25 there were 9 lambs. Parentage of the c o l l a r e d lambs was determined on August 7 by obs e r v i n g s u c k l i n g bouts, and the d i a g n o s i s of pregnancy was confirmed f o r a l l 8 females. Two of these d i d not lamb u n t i l a f t e r June 12, i n d i c a t i n g t h a t the pregnancy d i a g n o s i s occured when the f e t u s e s were l e s s than 114 days o l d . The other females were diagnosed when the f e t u s e s were approximately 130-140 days o l d . The g e s t a t i o n p e r i o d of C a l i f o r n i a bighorn sheep has been determined to be 174.2 +/- 1.70 days (Shackleton e t a l . 1984). The animal t h a t was diagnosed as non-pregnant was not seen s u c k l i n g a lamb. Pregnancy d e t e r m i n a t i o n of female bighorns was 100% accurate f o r both d i a g n o s i s of pregnancy (n=19), and d i a g n o s i s of 104 non-pregnancy (n=4), (Table 1 ) . PREGNANCY DETERMINATION OF DOMESTIC SHEEP Of the 9 domestic ewes t e s t e d a t the U n i v e r s i t y of B r i t i s h Columbia, 7 were diagnosed pregnant and 2 were diagnosed non-pregnant. These diagnoses were confirmed when the ewes lambed. In the second sample of 50 ewes from a commercial farm a t o t a l , of 6 e r r o r s i n d i a g n o s i s occured, a l l the r e s u l t of diag n o s i n g pregnant animals as non-pregnant. Thus the accuracy f o r domestic sheep was 100% f o r p o s i t i v e d i a g n o s i s and 54% f o r negative d i a g n o s i s (Table 1). The o v e r a l l accuracy of both p o s i t i v e and negative diagnoses was 90%. DISCUSSION The r e s u l t s of t h i s study i n d i c a t e t h a t the the Doppler u l t r a s o u n d technique, using an e x t e r n a l probe, i s both p r a c t i c a l and e f f e c t i v e f o r dia g n o s i n g pregnancy i n bighorn sheep. The o v e r a l l accuracy of pregnancy d i a g n o s i s was higher f o r bighorn females than f o r domestic sheep. There are two p o s s i b l e e x p l a n a t i o n s f o r t h i s . F i r s t l y , the bighorn were t e s t e d i n the l a s t t h i r d of g e s t a t i o n whereas the m a j o r i t y of the domestic sheep were i n t h e i r second t r i m e s t e r . No e r r o r s occurred i n those domestic ewes t e s t e d i n t h e i r t h i r d t r i m e s t e r . The l a r g e r f e t a l mass present l a t e r i n g e s t a t i o n makes i t l e s s l i k e l y t h a t a 105 pregnancy would be overlooked d u r i n g u l t r a s o n i c scanning. A second e x p l a n a t i o n may be t h a t the maximum number of bighorns processed a t one time was 11. T h i s allowed more time to be spent d i a g n o s i n g each female. The 6 e r r o r s o c c u r r e d when 50 domestic ewes were processed a t one time, and might have been avoided i f more time had been spent i n the d i a g n o s i s of non-pregnancy. Doppler u l t r a s o u n d i s accurate i n the p o s i t i v e d i a g n o s i s of pregnancy. M i s d i a g n o s i s of pregnancy i n a non-pregnant i n d i v i d u a l i s u n l i k e l y u n l e s s extraneous sounds are m i s i n t e r p r e t e d as being a s s o c i a t e d with f e t a l t i s s u e . However, e r r o r i n the d i a g n o s i s of non-pregnancy ( p r e d i c t i o n of non-pregnancy i n a pregnant female) i s p o s s i b l e , because the absence of sounds c h a r a c t e r i s t i c of pregnancy can be due to improper probe placement and operator i n e x p e r i e n c e . I t i s s i g n i f i c a n t t h a t the onl y e r r o r s i n t h i s study occured as a r e s u l t of p r o c e s s i n g a l a r g e number of animals i n a short p e r i o d of time. E r r o r s i n the d i a g n o s i s of non-pregnancy c o u l d probably be reduced by t e s t i n g females diagnosed as non-pregnant on two separate o c c a s i o n s . The accuracy of p r e d i c t i n g non-pregnancy i n domestic ewes improved c o n s i d e r a b l y when the animals were examined twice (Lindahl 1972). I t a l s o may be p o s s i b l e to reduce e r r o r by using an i n t r a r e c t a l probe, which i s more accurate i n e a r l y g e s t a t i o n (Deas 1977) . U n f o r t u n a t e l y , a c c u r a c y with the 106 i n t r a r e c t a l probe decreases a f t e r m i d - g e s t a t i o n , and there i s a p o s s i b i l i t y of causing i n j u r y , p e r i t o n i t i s , and a b o r t i o n (Trapp and S l y t e r 1983) . The p r o b a b l i l i t y of such i n j u r y c o u l d be even g r e a t e r i n w i l d s p e c i e s . In c o n c l u s i o n , i t appears t h a t Doppler u l t r a s o u n d should be a u s e f u l technique f o r determining pregnancy r a t e s i n w i l d bighorn sheep p o p u l a t i o n s , provided t h a t the females are a t l e a s t 110 days pregnant. In a d d i t i o n to being an accurate technique, an important advantage i s the immediate d i a g n o s i s of r e p r o d u c t i v e s t a t u s , a c o n s i d e r a t i o n f o r some f i e l d s t u d i e s . In t h i s study, a compact weather r e s i s t a n t instrument, which used 2MHz u l t r a s o u n d from an e x t e r n a l t r a n s d u c e r , a c c u r a t e l y and r a p i d l y determined the pregnancy r a t e of c a p t i v e bighorn females. ACKNOWLEDGEMENTS The r e s e a r c h r e p o r t e d here i s p a r t of a j o i n t p r o j e c t among the B r i t i s h Columbia M i n i s t r y of Environment, the U n i v e r s i t y of B r i t i s h Columbia, and the Okanagan Game Farm. E. Lacey, l a t e of the Okanagan Game Farm pr o v i d e d l o g i s t i c a l support and D. Eastman, R. Peterson and H. Lacey a s s i s t e d i n ha n d l i n g the big h o r n . We thank H. Nordan f o r a l l o w i n g us to sample the U n i v e r s i t y of B r i t i s h Columbia bighorn, and A. S c h a e f f e r and D. Hunt f o r a l l o w i n g us to sample t h e i r domestic sheep. F i e l d 107 r e s e a r c h was supported by funds from the Science C o u n c i l of B r i t i s h Columbia. D. Shackleton and R. T a i t c o n s t r u c t i v e l y reviewed the d r a f t manuscript. LITERATDRE CITED BARRETT, R. H. 1981. Pregnancy d i a g n o s i s with Doppler u l t r a s o n i c f e t a l p u l s e d e t e c t o r s . W i l d l . Soc. B u l l . 9:60-63. DEAS, D. W. 1977. Pregnancy d i a g n o s i s i n the ewe by an u l t r a s o n i c r e c t a l probe. Vet. Rec. 101:113-115. FOLLIS, T. B. and J . J . SPILLET. 1974. Winter pregnancy r a t e s and subsequent f a l l cow/calf r a t i o s i n e l k . J . W i l d l . Manage. 38:789-791. LINDAHL, I. L. 1972. E a r l y pregnancy d e t e c t i o n i n ewes by i n t r a r e c t a l r e f l e c t i o n u l t r a s o u n d . J . Anim. S c i . 34:772-775. MEMON, M. A. and R. S. OTT. 1980. Methods of pregnancy d i a g n o s i s i n sheep and goats. C o r n e l l Vet. 70:226-231. RAMSAY, M. A. and R. M. F. S. SADLEIR. 1979. D e t e c t i o n of pregnancy i n l i v i n g bighorn sheep by p r o g e s t i n d e t e r m i n a t i o n . J . W i l d l . Manage. 43:970-973. REHBINDER, C , L. E. EDQVIST, U. RIESTEN-ARHED and M. NORDQVIST. 1981. Progesterone i n pregnant and non-pregnant r e i n d e e r . Acta Vet. Scand. 22:355-359. ROSE, J . L. and B. B. GOLDBERG. 1979. B a s i c P h y s i c s i n D i a g n o s t i c U l t r a s o u n d . John Wiley & Sons. New York, N.Y. 340 pp. SHACKLETON, D. M., R. G. PETERSON, J . HAYWOOD, and A. BOTTRELL. 1984. G e s t a t i o n p e r i o d i n Ovis canadensis. J . Mamm. 65:337-338. " SMITH, R. B. and F. G. LINDZEY. 1982. Use of u l t r a s o u n d f o r d e t e c t i n g pregnancy i n mule deer. J . W i l d l . Manage. 46:1089-1092. 108 TRAPP, M. J . and A. L. SLYTER. 1983. Pregnancy d i a g n o s i s i n the ewe. J . Anim. S c i . 57:1-5. TURNER, J.C. 1983. A f i e l d laparotomy technique f o r observing the r e p r o d u c t i v e t r a c t of f r e e - r a n g i n g d e s e r t bighorn sheep (Ovis canadensis cremnobates). Theriogenology 19:787-794. WANI, G. M. and K. L. SAHNI. 1981. U l t r a s o n i c pregnancy d i a g n o s i s i n ewes under t r o p i c a l f i e l d c o n d i t i o n s . Indian J . Anim. S c i . 51:194-197. WHITEHEAD, P. E. and E. H. MCEWAN. 1980. Progesterone l e v e l s i n the p e r i p h e r a l plasma of Rocky Mountain bighorn ewes Ovis canadensis d u r i n g the es t r o u s c y c l e and pregnancy. Can. J . Z o o l . 58:1105-1108. 1 0 9 Table 1. Accuracy of both p o s i t i v e and negative diagnoses of pregnancy i n bighorn females and domestic ewes  LOCATION AND YEAR BIGHORN FEMALES DOMESTIC EWES UBC OKGF OKGF Tot a l 1982 1982 1983 Bighorn Hunt Total UBC Farm Domestic 1982 1983 Ewes # tested with ultrasound # diagnosed pregnant # nursing lambs % c o r r e c t l y diagnosed pregnant # diagnosed non-pregnant % c o r r e c t l y diagnosed non-pregnant % o v e r a l l accuracy 11 23 3 8 . 8 19 3 7+(l)* 8 18+(1)* 100% 100%* 100% 100% n/a 100% 100% 100% 100% 100% 100% 100% 50 39 39 100% 100% 11 100% 45% 100% 88% 59 46 46 100% 13 54% 90% ft - Number * - assuming one female which was diagnosed pregnant, was l a c t a t i n g , but was not observed nursing, was the dam of a mortality discovered. UBC - Un i v e r s i t y of B r i t i s h Columbia, Vancouver, B.C. OKGF - Okanagan Game Farm, Penticton, B.C. 110 Appendix 2. D e s c r i p t i o n of the c h a r a c t e r i s t i c s used t o d e f i n e the Body C o n d i t i o n Score s c a l e used i n t h i s study ( a f t e r Russel e t al. 1969) . SCORE 0: Extremely emaciated and on the p o i n t of death. I t i s not p o s s i b l e to d e t e c t any muscular or f a t t y t i s s u e between s k i n and bone. SCORE 1: The spinous processes are f e l t to be prominant and sharp. The t r a n s v e r s e processes are a l s o sharp, the f i n g e r s pass e a s i l y under the ends, and i t i s p o s s i b l e to f e e l between each p r o c e s s . The eye muscle areas are shallow w i t h no f a t cover. SCORE 2: The spinous processes s t i l l f e e l prominent, but smooth, and i n d i v i d u a l processes can be f e l t o n l y as f i n e c o r r u g a t i o n s . The t r a n s v e r s e processes are smooth and rounded, and i t i s p o s s i b l e to pass the f i n g e r s under the ends with a l i t t l e pressure.>• The eye muscle areas are of moderate depth, but have l i t t l e f a t cover. SCORE 3: The spinous processes are de t e c t e d o n l y as small e l e v a t i o n s ; they are smooth and rounded, and i n d i v i d u a l bones can be f e l t o n l y with p r e s s u r e . The t r a n s v e r s e processes are smooth and w e l l covered, and f i r m pressure i s r e q u i r e d to f e e l over the ends. The eye muscle areas are f u l l , and have a moderate degree of f a t cover. SCORE 4: The spinous processes can j u s t be d e t e c t e d , with p r e s s u r e , as a hard l i n e between the f a t covered eye muscle area. The ends of the t r a n s v e r s e processes cannot be f e l t . The eye muscle areas are f u l l , and have a t h i c k c o v e r i n g of f a t . SCORE 5: The spinous processes cannot be d e t e c t e d even with f i r m p r e s s u r e , and there i s a d e p r e s s i o n between the l a y e r s of f a t i n the p o s i t i o n where the spinous process would normally be f e l t . The t r a n s v e r s e processes cannot be d e t e c t e d . The eye muscle areas are very f u l l w i t h very t h i c k f a t cover. There may be l a r g e d e p o s i t s of f a t over the rump and t a i l . I l l * ** Appendix 3. Trace mineral c o n c e n t r a t i o n s of l i v e r and kidney t i s s u e on a wet weight b a s i s from bighorn sheep from s o u t h - c e n t r a l B r i t i s h Columbia. L i v e r (mg.kg ^) Kidney (mg.kg ^) Element x sd n x sd n Iron 99 58 25 73 38 17 Copper 68 47 25 4.8 1.6 17 Zinc 37 18 25 23 8.0 17 Manganese 3.4 1.3 25 1.6 0.6 17 Selenium 0.27 0.08 25 * L i v e r samples came from Vaseux Lake (n=12), the Ashnola (n=12), and B i g Bar (n=l). Seventeen were from males, f i v e from females, two from f e t u s e s , and one from a newborn lamb. ** Kidney samples came from Vaseux Lake (n=8), and from the Ashnola (n=9). Nine were from males, four from females, two from f e t u s e s , and two from lambs. 112 Appendix 4. Comparison of the c h a r a c t e r i s t i c s of those tagged females which s u c c e s s f u l l y r eared a lamb to three months o l d , to those t h a t l o s t t h e i r lambs when they were l e s s than one month o l d . S u c c e s s f u l Unsuccessful Female* Female** V a r i a b l e Mean (n) Mean (n) Liveweight (kg) 58.5 (3) 62.6 (6) C h e s t g i r t h (mm) 1009 (4) 1011 (6) T o t a l Length (mm) 1605 (4) 1620 (4) Hi n d f o o t Length (mm) 394 (4) 391 (6) Body C o n d i t i o n Score 2.0 (4) 2.4 (6) PI-3 i n f e c t i o n 75% (4) 50% (6) Serum selenium(mg.kg 1) 0.08 (2) 0.10 (3) Serum copper (mg.kg 0.77 (1) 0.66 (3) Serum z i n c (mg.kg ^) 0.48 (1) 0.53 (3) Serum i o d i n e (mcg%) 5.00 (1) 5.33 (3) Serum c a l c i u m (mg%) 7.70 (1) 7.77 (3) Serum phosphorus (mg%) 2.80 (1) 2.97 (3) Serum magnesium (mg%) 1.55 (1) 2.09 (3) * females whose lambs s u r v i v e d to three months o l d . ** females whose lambs d i e d before they were one month o l d . 

Cite

Citation Scheme:

        

Citations by CSL (citeproc-js)

Usage Statistics

Share

Embed

Customize your widget with the following options, then copy and paste the code below into the HTML of your page to embed this item in your website.
                        
                            <div id="ubcOpenCollectionsWidgetDisplay">
                            <script id="ubcOpenCollectionsWidget"
                            src="{[{embed.src}]}"
                            data-item="{[{embed.item}]}"
                            data-collection="{[{embed.collection}]}"
                            data-metadata="{[{embed.showMetadata}]}"
                            data-width="{[{embed.width}]}"
                            async >
                            </script>
                            </div>
                        
                    
IIIF logo Our image viewer uses the IIIF 2.0 standard. To load this item in other compatible viewers, use this url:
http://iiif.library.ubc.ca/presentation/dsp.831.1-0096116/manifest

Comment

Related Items