There have been alarming declines in the number of California bighorn sheep in the Similkameen region of British Columbia since the latter part of the nineteenth century. Present conflict for food supply with domestic stock makes further herd reduction imminent. This study was initiated to gather sound ecological data on which to base management and conservation practises for the California bighorn sheep in British Columbia and to determine population status of the Ashnola herd. The Ashnola herd was studied in the field from May 1960 through June 1961. The study area is described on the basis of broad soil and vegetation patterns. Line point transects were employed to determine botanical composition of important winter ranges. The sheep population is analysed from age and sex ratios and age structure data. Age structure was determined by collecting remains, in the field, of sheep which died of natural causes. Natality and mortality rates from the above sources indicate that the herd is relatively stable. Census data substantiates this observation. Factors limiting population increase are evaluated with emphasis on competition for food. Predation, accidents and hunting are not considered to be presently limiting herd increase. Incidence of parasitism in the herd was investigated by post mortem examination and fecal analysis. No deaths directly attributable to parasitism were noted during the study. Grazing by cattle appears to be the primary land use presently threatening the welfare of the herd. Bighorn sheep-cattle competition involves spring and fall utilization by cattle of sheep winter ranges. Direct and indirect observation of animal distribution, food habit analysis and exclosure plot technique have been employed to evaluate the competitive interaction. Although competition was slight in 1960, food shortage resulting from cattle grazing and occasional severe snow conditions is suggested as the factor limiting herd increase. Aspects of herd biology and behavior such as rutting, lambing, migration and social organization are also described. Management considerations and recommendations are briefly discussed. / Science, Faculty of / Zoology, Department of / Graduate

Stone sheep (Ovis dalli stonei) and a representative, undisturbed habitat for this species were studied in the northern Rocky Mountain Foothills from May 1969 through May 1971. A highly descriptive and holistic approach was taken in this introductory study, with physiography, soils, climate, and vegetation and the native sheep all being assessed. The study was concerned primarily with the alpine sheep habitat with emphasis on the critical winter range. Vegetation in this northern environment, reflecting physiographic, climatic and edaphic diversity, presents a complex, heterogeneous pattern locally to a degree seldom observed in more southern latitudes. Local variations in climate, on different slopes and aspects, have produced striking floristic differences within short distances. Moreover, soils developed over different bedrock formations and distrubed little by glaciation contributed considerably to diversity in the alpine habitat. Extremely acid soils characterized by impeded drainage and low temperatures limited forage production over much of the habitat. However, soils developed over calcareous parent materials on southern exposures had the favourable characteristics of moderately coarse texture, good drainage and an adequate nutrient status. These soils supported relatively productive plant communities and high quality forage for the sheep. The vegetation was also characterized by stability especially in the alpine zone; this zone is largely free of a fire history and is characterized by climax or long-term disclimax communities. Apparent deteriorating climate over long periods may be very significant, however, because in all likelihood they reduce favourable sheep habitat. Stone sheep were almost entirely dependent on the herbaceous alpine vegetation for their nutritional requirements. Even though plant succession proceeds slowly at these latitudes, seral grasslands tended to be invaded quite rapidly by shrubs which reduced the herbaceous cover and caused drifting snow to accumulate in winter. Grasses and sedges made up 95.6 percent of the winter diet and 78.5 percent of the fall diet of sheep collected in the Nevis Creek study area. Vegetative diversity contributed largely to a balanced habitat for the sheep and the fortuitous combinations of factors of climate, soils and vegetation provided critical winter range on largely snow-free slopes with southern exposures. Three plant communities provided winter forage but one, the Elymus - Agropyron community, provided almost 60 percent of the forage utilized by wintering sheep. About 80 percent of the standing crop in this community, which made up only about 20 percent of the winter range and four percent of the total productive habitat by area, was utilized by the sheep. Although productivity was typically low in this alpine ecosystem, forage quality was relatively high and was maintained in the cured stage by hard fall frosts and the persistent winter cold. Counts conducted in summer and winter over an extensive portion of the northern foothills and Rocky Mountains showed stone sheep populations averaged 35 percent mature ewes, 28 percent mature rams, 15 percent yearlings and 22 percent lambs (n=981). Early summer counts for two seasons in the study area showed an average ratio of 74 lambs per 100 ewes two years of age or older indicating a high birth rate and low mortality in the first few weeks of life. The lambs experienced almost 50 percent mortality by the end of their first year; however, most of it occurred early in the first winter. Classified counts of the ram segment of the population indicate a period of low mortality during adult life to age 8 or 10 years. Of course, intraspecific competition and malnutrition during severe winter conditions, disease and parasites, injury, predation and hunting all contributed to mortality to some degree. Stone sheep populations reflect the stability of their relatively undisturbed alpine habitat. Actinomycosis and lungworm were common in sheep at Nevis Creek but there is no record of large-scale enzootic die-offs in this or other stone sheep populations such as occur in bighorn populations due to lungworm-pneumonia disease. Stone sheep habitat, once remote, is rapidly becoming more accessible and subject to man's influence with development of the north. Interference in this northern environment by man must consider its sensitivity to abuse and its slow recovery. Any change or destruction of this northern sheep habitat, particularly the important and restricted elements such as the Elymus - Agropyron plant community on the Nevis Creek winter range, would unquestionably seriously reduce the sheep populations dependent upon it. / Land and Food Systems, Faculty of / Graduate

Protostrongylus stilesi, the parenchymal lungworm, has been attributed an important role in the widespread respiratory diseases of the Rocky Mountain bighorn sheep (Ovis canadensis canadensis). This study was conducted to delineate some of the immunologic and non-specific interactions between parasite and host. A procedure was developed for- the immunochemical quantitation of the ovine immunoglobulins IgG(1), IgG(2) and IgM and for the semi-quantitative analysis of IgA. This technique obviated, the preparation of highly specific antisera required for single radial immunodiffusion. The lungworm did not appear to be a significant part of the total antigenic environment of infected animals since no relationship between immunoglobulin levels and parasite activity was detected. Genetic influences were suggested in the levels of IgG(2) which remained at a relatively constant level characteristic of individual animals. The seromucoids were evaluated as correlates of the inflammatory reaction to parasitism. These proteins were useful in detecting changes in parasite activity and bacterial infection. Gastrointestinal disorders associated with severe scouring were accompanied by the disappearance of circulating orosomucoid (α-1 acid glycoprotein). The loss of this low molecular weight protein appeared to be related to vascular leakage. Lungworm infections induced the appearance of homocytotropic antibodies which could be detected in vitro by their ability to sensitize peripheral polymorphonuclear leucocytes for adherence to the larval cuticle. The elution of this antibody from sensitized cells and the inhibition of the adherence reaction with specific antiserum suggested that the reaction was mediated at least partly by IgG(1). The adherence reaction was used to assay homocytotropic activity of serum from infected animals (washed-cell test). This test was correlated with the ability of sera to sensitize skin for anaphylaxis. The effective hypersensitive response, accounting for both sensitizing and blocking activity, was determined by exposing normal cells to larvae in a medium containing serum (decomplemented-serum test). The results of this test paralleled inflammatory changes in parasitized animals, monitored by the levels of serum orosomucoid. Using this method, levels of homocytotropic and blocking antibodies were measured throughout the annual parasite cycle. Preliminary observations indicated that immunogenic inflammation, associated with the "spring rise" and "self cure," resulted from a shift in a dynamic balance between competing antibodies rather than a proportionate increase in homocytotropic activity. The response of peripheral lymphocytes to the presence of larvae or larval extracts was cursorily examined. Although ovine lymphocytes did not respond well enough in culture to draw definitive conclusions, the presence of larval extracts appeared to have a detrimental effect on cell survival and transformation. Even in the presence of EDTA, minute amounts of antibody sensitized lymphocytes for adherence to the larval cuticle. Sera from a wide variety of sources had an inhibitory effect on this reaction. Treatment of larvae with neuraminidase and high concentrations of NaCl engendered improved adherence. This suggested that Protostrongylus had adopted mechanisms similar to the trophoblast or the neoplastic cell which allegedly evade immunologic recognition with a strongly anionic coat. These aspects are discussed in terms of the possible role of Protostrongylus in respiratory diseases of the bighorn sheep, and the exploitation of molecular mechanisms in the control of parasitic diseases. / Land and Food Systems, Faculty of / Graduate

Seventeen cougars (Felis concolor) utilizing the Junction Wildlife Management Area (W.M.A.) in central British Columbia were fitted with radio collars. All collared cougars within the area were relocated using ground-based and aerial radio telemetry. Relocations were made daily during intensive field work (December-August), and a minimum of four per week the remainder of the year. General site reconnaissance and direct sampling work from 1986 to 1988 revealed 132 prey species mortalities of which 50 were confirmed as recent cougar kills. Although bighorn ewes and lambs (Ovis canadensis californiana) were not important prey items for the cougars, bighorn rams comprised 77.6% of the total mortality sample and 46.5% of the confirmed cougar kills. Cougars selected rams in greater proportion than would be expected based on the availability of rams in the prey population. Poor post-rut body condition and restricted rear and peripheral vision were factors that increased the rams' vulnerability to cougar predation. Cougar predation rates on bighorn sheep and mule deer (Odocoileus hemionus hemionus) were determined for two females with kittens. Kill rates varied from 0.7 - 3.0 ungulates/week. Interactions between cougars and coyotes (Canis latrans) at kill sites influenced the cougars' utilization of kills and predation rates. In 200 km² of the 425 km² study area, 130 coyotes were removed over a two-year period. The predation rate of a cougar with three kittens within the coyote removal area averaged 1.1 kills/week while that of a female with two similarly-aged kittens in the non-removal area averaged 2.6 kills/week. Moreover, observations of cougars abandoning kills following harassment by coyotes, suggested that cougar/coyote interactions were an important part of the system. Poor lamb recruitment and a decline in the number of mature rams in the Junction herd are a concern for the Ministry of Environment (MOE) Wildlife Branch. I make two recommendations that address these concerns: 1. Maintain the resident cougar population without removing cougars. Cougars were not important predators of the lamb segment, nor were cougars keying on the older, larger rams. Moreover, removal of the resident cougar population will disrupt the intraspecific and territorial dynamics of the cougar population resulting in an influx of transient cougars. This, in turn, will lead to the Junction system stabilizing at cougar numbers equal to or possibly greater than pre-removal levels. 2. Initiate an alternating, two-year on, two-year off, February-April coyote removal program until Iamb recruitment remains above 20 lambs/100 ewes throughout a four-year cycle. This program is preferable to cougar removal in that coyote removal can be implemented more effectively on a temporally and spatially scale. Coyote removal will result in an increase in lamb recruitment to the bighorn population, including the ram component. Moreover, fewer rams from this increased population will be killed because of lower cougar predation rates that also will result from the decrease in coyote scavenging/displacement pressures. / Science, Faculty of / Zoology, Department of / Graduate