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Russian thistle (Salsola tragus L.) invaded areas of native montane grassland important to winter survival of bighorn sheep (Ovis canadensis Shaw) were studied in Jasper National Park, Alberta, Canada. The biology of Russian thistle and its control in the Park were studied in the field and greenhouse. Russian thistle in grasslands were 9.1 cm tall with 37.5 seeds per plant, whereas larger plants in naturally disturbed habitats were 29.8 cm tall with 1562.4 seeds per plant. Plants travelled up to 4,180 m during dispersal. With soil seed contact, litter depth did not inhibit performance or survivability; without soil contact, thick litter reduced germination and plant performance. Russian thistle responded positively to increased greenhouse temperature and drier conditions. Seven control treatments involving herbicide, seeding mixes, hand pulling, and grazing exclusion were assessed. Grazing exclusion was the best field management option, increasing litter and biomass, while reducing Russian thistle density and biomass. / Land Reclamation and Remediation

Habitat use by mule deer, particularly in relation to use by cattle and by California bighorn sheep on the bighorn winter-spring ranges of Flatiron Mountain was studied from January 1968 through November 1969. Observations were made of (1) food habits, (2) forage production and utilization, (3) the effect of spring and summer utilization on subsequent forage production and (4) spatial and temporal distribution of range use. The results indicate that competition for forage between the native ungulates, deer and sheep, is largely obviated by differential habitat use. This may point to long term evolutionary ecological niche specialization. Some competition for forage occurs for a short period in the early spring when both ungulate species seek succulent new grass, the supply of which is at first limited. Cattle use of the winter-spring ranges was excessive and the diets of cattle and the native ungulates are similar, with the exception that utilization of grass by deer was less. Range use by cattle contributed to intra-specific cattle-deer competition on the grasslands in the spring and cattle-bighorn competition on the grasslands during the winter. The study of spring range utilization indicated that deer use was not detrimental to the 1969 annual forage production in areas used by deer. Spring range utilization by bighorn or bighorn in combination with deer reduced the standing crop of forage produced on the Agropyron spicatum dominated winter-spring ranges. Sheep utilization on South Slope during the summer, when forage growth was declining, further reduced the amount of forage available to the wintering bighorn population. / 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

This study was undertaken to determine the interrelations among forage production and utilization, forage quality, forage availability, diet selection, and the subsequent impact of grazing by captive California bighorn sheep under controlled experimental conditions on an Artemisia - Agropyron plant community in southern interior British Columbia. Fourteen grasses, 58 forbs plus 18 trees and shrubs were available for grazing by the captive herd within a 42 ha experimental enclosure. Agropyron spicatum, Bromus tectorum and Artemisia tridentata were the dominant species on the site equaling 22.1, 9.5 and 6.7% of the cover respectively. Both annual and seasonal variations in plant species phenology, cover and botanical composition were evident among phenological groups, forage classes and individual species. Cover of grasses (51.4%) and forbs (24.1%) was highest in 1978 which was the wettest year, and it was lowest in 1979 which was the driest year equaling 34.2 and 12.8% for each group respectively. Cover of shrubs, and both cover and botanical composition of Agropyron spicatum varied little among years. Yields for total standing crop varied from 40.83 to 62.95 g/m² in 1977 and 1978 on the ungrazed areas in response to annual weather patterns. Fall regrowth was prevalent in 1978 and 1979 equaling 8.18 and 19.42 g/m² or 11.5 and 27.0% of the total herbage produced in each year respectively. Maximum availability of nutrients occurred in March and April each year, but from September through to November fall regrowth re-established nutrient levels to those recorded in the early growth stages for all plant species sampled. A total of 79 species consisting of 14 grasses, 47 forbs and 18 shrubs were observed in the diet of the experimental herd from 1977 to 1979. Grasses, forbs and shrubs comprised 66.6, 18.9 and 14.5% of the diet respectively over the 28 month study period. Agropyron spicatum was generally the most common plant found in the bighorn diet in all seasons, but this plant species typically occurred more frequently on the range than in the diet. Other grasses such as Festuca scabrella, Festuca idahoensis, Koeleria cristata and Stipa comata were preferred. Forbs were grazed most in summer (26.5 and 36.2%) and spring (19.2 and 18.4%) in 1977 and 1978 respectively. Perennial forbs were generally preferred but annual forbs were selected against by the bighorn sheep in all seasons. Browse was utilized most in winter and spring each year averaging 18.7 and 17.6% of the diet in each season respectively over the two year period. The dominant shrub, Artemisia tridentata was not preferred but most other browse species were. No consistent regressions could be established between forage consumption and corresponding nutritive quality of selected forage species. Balsamorhiza sagittata and Agropyron spicatum were least affected from grazing despite their importance in mountain sheep diet. Indeed, only leaf lengths differed among grazed and un-grazed Balsamorhiza sagittata plants and no significant differences were observed in basal diameters or the number of culms produced on grazed and ungrazed Agropyron spicatum plants after three years of grazing. Reductions in nearly all measured parameters were observed on grazed Koeleria cristata, Poa sandbergii, Stipa comata, Castilleja thompsonii, Lupinus sericeus and Erio- gonum niveum plants compared to ungrazed plants. Utilization of Amelanchier alnifolia was determined with three methods in 1977 and five methods in 1978. It was concluded that weight methods do not evaluate the impact of mountain sheep browsing any better than methods based on stem lengths. The long term effects of grazing by California bighorn sheep was evaluated from 1976 to 1983. Total cover remained virtually the same on the grazed (71.1 and 85.0%) and ungrazed (70.3 and 86.0%) areas between these two years respectively. Annual, perennial and individual plant species all reacted differently to grazing by mountain sheep. Cover of perennial grasses increased only slightly on both the grazed and protected areas between 1976 and 1983 but these differences were not statistically significant. No differences in either cover or botanical composition were observed between the grazed and ungrazed areas for Agropyron spicatum, Koeleria cristata or Poa sandbergii. Cover and botanical composition of forbs remained the same in 1983 compared to 1976 on the grazed areas. On the ungrazed areas, both cover and botanical composition of forbs increased over the same time period. Botanical composition of shrubs increased slightly on both the grazed and' ungrazed areas over the seven year period but cover for this group remained the same. Both Eriogonum niveum and Eriogonum heracleoides declined significantly on the areas grazed by bighorn sheep. Declines in both species were attributed to grazing pressure by the captive herd. / Land and Food Systems, Faculty of / Graduate

This project investigates federal, state and local agencies and organizations that are key sources of information about Peninsular bighorn sheep (Ovis canadensis cremnobates) to determine the extent of the agencies' environmental education and awareness programs related to the sheep. The agencies and organizations investigated include: Bureau of Land Management, Anza-Borrego Desert State Park, Living Desert Wildlife and Botanical Park, Bighorn Institute, Natural Science Collaborative of the Desert Region and California Desert Managers Group. Recommendations about future educational and interpretive programs are included.

Successful management of bighorn sheep depends on understanding the mechanisms responsible for population growth or decline, habitat selection, and utilization distribution after translocations. We studied a declining population of desert bighorn sheep in the North San Rafael Swell, Utah to determine birthdates of neonates, demographics, limiting factors, population size, probable cause of death, production, and survival. We documented 19 mortalities attributed to a variety of causes including cougar predation (n = 10, 53%), bluetongue virus (n = 2, 11%), reproductive complications (n = 2, 11%), hunter harvest (n = 1, 5%), and unknown (n = 4, 21%). Annual survival of females was 73% (95% CI = 0.55—0.86) in 2012 and 73% (95% CI = 0.55—0.86) in 2013. Adult male survival was 75% in 2012 (95% CI = 0.38—0.94) and 88% (95% CI = 0.50—0.98) in 2013. Disease testing revealed the presence of pneumonia-related pathogens. The population increased from an estimated 127 in 2012 to 139 in 2013 (λ = 1.09). Lamb:ewe ratios were 47:100 in 2012 and 31:100 in 2013. Mean birthing dates were 21 May in 2012 and 20 May in 2013. Spatial separation from domestic sheep and goats, and aggressive harvest of cougars, may have aided in the recovery of this population after disease events. Second, we investigated the timing of parturition and nursery habitat of desert bighorn sheep in the North San Rafael Swell to determine the influence of vegetation, topography, and anthropogenic features on resource selection. We monitored 38 radio-tagged ewes to establish birthing dates. We documented birthdates of 45 lambs. We used collar-generated GPS locations to perform logistic regression within a model-selection framework to differentiate between nursery and random locations (n = 750 for each) based on a suite of covariates. The top model included elevation, slope, ruggedness, aspect, vegetation type, distance to trails, and distance to roads. We used these variables to create a GIS model of nursery habitat for the North San Rafael (desert bighorns) and the Green River Corridor (Rocky Mountain bighorns). Ewes showed preference for steep, north-facing slopes, rugged terrain, lower elevation, and avoidance of roads. Our model provides managers with a map of high probability nursery areas of desert and Rocky Mountain bighorns to aid in conservation planning and mitigate potential conflicts with industry and domestic livestock. Finally, we monitored 127 reintroduced female bighorn sheep in three adjacent restored populations to investigate if the size and overlap of habitat use by augmented bighorns differed from resident bighorns. The size of seasonal ranges for residents was generally larger than augmented females. However, there was a shift in utilization distribution in all three populations after augmentation. Overlap indices between resident and augmented sheep varied by source herd. These data will help managers understand the dynamics of home range expansion and the overlap between provenance groups following augmentations.

Conservation biologists have used reintroduction as a method to reestablish extirpated species in their native habitat. Three important aspects of a successful reintroduction effort include: (1) a habitat suitability study of the reintroduction area, including effects of migration corridors; (2) identification of possible predators of the reintroduced species; and (3) a post-reintroduction assessment including an evaluation of the species' population dynamics. In this study I examine the suitability of Guadalupe Mountains National Park (GUMO) as a reintroduction area for desert bighorn sheep. The study used landscape metrics to compare GUMO to a nearby mountain range that is currently supporting an estimated population of 400 bighorn sheep. This study identified migration corridors for bighorns throughout the region and evaluated mountain lion (a potential predator of bighorn sheep) numbers either residing in or passing through the park between the years 1997 to 2004. Results on the studies in GUMO revealed 15,884 ha of suitable habitat for bighorn sheep and provided evidence of migration routes between GUMO and neighboring mountain ranges. In terms of potential predators, a minimum of 32 resident and/or transient mountain lions occurred in GUMO over a seven year period, and a minimum of 15 cats used the park in 2002. Based on estimates of individual home range of males and females, GUMO should be able to support four to five individuals. The genetic data indicates a high number of transients or perhaps an unstable population of mountain lions that may be the result of intense hunting pressure of cats in Texas. Finally, my study simulates parameters of the population dynamics of a different species, the Arabian oryx that was reintroduced as three separate populations to the Israeli Negev between 1998 and 2005. I simulated population growth and the effect of migration corridors on species persistence. Results suggest that migration corridors are essential for a self-sustaining viable metapopulation under current natality rates. In the event that natality rates increase (as was evident in a reintroduced population of Arabian oryx in Oman), metapopulation can reach viable size with only two of the release sites (open, flat terrain) connected by migration corridors.

Conservation biologists have used reintroduction as a method to reestablish extirpated species in their native habitat. Three important aspects of a successful reintroduction effort include: (1) a habitat suitability study of the reintroduction area, including effects of migration corridors; (2) identification of possible predators of the reintroduced species; and (3) a post-reintroduction assessment including an evaluation of the species' population dynamics. In this study I examine the suitability of Guadalupe Mountains National Park (GUMO) as a reintroduction area for desert bighorn sheep. The study used landscape metrics to compare GUMO to a nearby mountain range that is currently supporting an estimated population of 400 bighorn sheep. This study identified migration corridors for bighorns throughout the region and evaluated mountain lion (a potential predator of bighorn sheep) numbers either residing in or passing through the park between the years 1997 to 2004. Results on the studies in GUMO revealed 15,884 ha of suitable habitat for bighorn sheep and provided evidence of migration routes between GUMO and neighboring mountain ranges. In terms of potential predators, a minimum of 32 resident and/or transient mountain lions occurred in GUMO over a seven year period, and a minimum of 15 cats used the park in 2002. Based on estimates of individual home range of males and females, GUMO should be able to support four to five individuals. The genetic data indicates a high number of transients or perhaps an unstable population of mountain lions that may be the result of intense hunting pressure of cats in Texas. Finally, my study simulates parameters of the population dynamics of a different species, the Arabian oryx that was reintroduced as three separate populations to the Israeli Negev between 1998 and 2005. I simulated population growth and the effect of migration corridors on species persistence. Results suggest that migration corridors are essential for a self-sustaining viable metapopulation under current natality rates. In the event that natality rates increase (as was evident in a reintroduced population of Arabian oryx in Oman), metapopulation can reach viable size with only two of the release sites (open, flat terrain) connected by migration corridors.

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