The persistence of grizzly bears (<i>Ursus arctos</i>) in western Alberta is threatened by increasing human activities on the landscape. The Foothills Research Institute Grizzly Bear Program (FRIGBP) hypothesizes human-caused landscape change in Alberta causes long-term stress in individual bears, resulting in impaired biological functions and, when many bears are affected, decreased population performance. To facilitate the evaluation of individual grizzly bear health within the FRIGBP, the objective of my research was to develop and assess the usefulness of a health function score system for grizzly bears. From a large set of complex biological data collected from grizzly bears from 1999 to 2007, I merged 14 � constituent� variables into four health functions; growth, immunity, movement, and stress. For each health function, I calculated individual scores by adding ranked and weighted variable percentiles. I found that health function scores corresponded well with health status of individual bears based on values for multiple constituent variables. The score system facilitated quick screening of health in individual bears, identification of bears with reduced health, and comparison of health profiles between bears. I examined the usefulness of the score system by evaluating relationships presumed to exist under the working hypothesis of the FRIGBP. Results generated from health function scores were compared with those from constituent variable values using statistical and graphical techniques. I concluded that scores likely provided clearer depiction of wildlife health relationships than did constituent variables because they were not influenced by capture method, sex, or outlying observations. By using the score system, I found support for the proposed positive relationship between human-affected landscape condition and stress, but not for inverse relationships between stress and other health functions. The usefulness of the score system could be increased by minimizing use of redundant constituent variables, e.g., in growth and immunity, and removing the influence of potential confounding factors, e.g., capture.

Thesis (Ph. D.)--University of Missouri-Columbia, 2000. / Typescript. Vita. Includes bibliographical references (leaves 379-401). Also available on the Internet.

No description available.

Because most grizzly bear mortalities occur near roads, the Province of Alberta plans to implement gated access management. Little is known about how grizzly bears will respond to road closures because the effects of roads are confounded by habitat and human use. I examined mechanisms underlying grizzly bear habitat selection near roads on private and public lands of southwestern Alberta. I incorporated habitat selection models into an analysis of conflict risk. Grizzly bears selected areas near roads with low traffic and were most active at night on private lands, where human use was low. However, habitat selection varied among individuals, and roads were not a consistent predictor of overall habitat selection across individual bears. Patterns of habitat selection led to the emergence of ecological traps on private land. Access and attractant management should be implemented to reduce bear-human conflicts, and decrease displacement of bears from high-quality habitats. / Ecology

Thesis (Ph. D.)--University of Missouri-Columbia, 2000. / Typescript. Vita. Includes bibliographical references (leaves 379-401). Also available on the Internet.

Individual variation and fitness are the cornerstones of evolution by natural selection. The trophic niche represents an important source of phenotypic variation on which natural selection can act. Although individual variation is fundamental to species-level ecological and evolutionary change, individual variation is often ignored in population-level approaches to wildlife ecology, conservation and management. Failing to link individual resource use to fitness or to biological outcomes related to fitness limits us to managing for the average resource needs of a population, which may be insufficient for protecting the diversity of resource use within populations and the underlying eco-evolutionary processes that generate that diversity. My goals were to provide insights into the mechanisms that generate and constrain intrapopulation trophic niche variation, evaluate whether linkages exist between individual biological outcomes and variation in food habits across the range of resources consumed within generalist consumer populations and examine how that variation manifests in population-level responses. I investigated the causes and physiological consequences of intrapopulation trophic niche variation in two generalist consumers, the American black bear (Ursus americanus) and brown bear (U. arctos) across three sites in British Columbia, CAN and at one site in Alaska, USA. My primary tools included stable isotope analysis to estimate diet, enzyme-linked immunoassay of hair to quantify the hormone cortisol for indexing physiological stress, and genetic analyses to identify individuals, species, and sex and to estimate ancestry. I found that individual differences in resource use can result in similar biological outcomes and that similar resource use can result in different biological outcomes. Intra- and interspecific competition, sex-based differences in nutritional and social constraints and annual variation in food availability all influenced trophic niche variation and the resultant biological outcomes. I also found evidence of a link between intrapopulation trophic niche variation and population genetic structure. My results highlight the diverse ecological drivers and diverse consequences of trophic niche variation, which further illuminates why the trophic niche is a nexus for eco-evolutionary dynamics.

During 1982-85, population dynamics and denninq ecology of black bears (Ursus americanus) were investigated in Shenandoah National Park, Virginia. Foot snares and culvert traps were used to capture 115 bears a total of 149 times. Radio transmitter collars were fitted to 47 bears. The age structure of the bears captured was indicative of an exploited population. The minimum breeding age of females was 2 years, but 3 years was the modal age. Mean litter size determined by cub counts was 2.0 and females usually bred every second year. Annual mortality rates were estimated at 30% for cubs, 54% for yearlings, 39% for 2-year olds, and 21.5% for older bears. Radio collared adult males had an annual mortality rate of 41.5%, over 5-fold that of adult females (7.5%). Bear density was estimated at 1 bear/0.96-1.49 km'. This high density was explained in part by the difference in male and female mortality rates. The estimated rate of population increase indicated that the population was stable. The most common den types were rock cavities (29 of 61) and above-ground tree cavities (19 of 61). Males did not den in tree cavities. Den sites were not selected for forest type, aspect, or elevation, but ground slope was greater at den sites (P < 0.001) than at random points. Among- and within-year differences in dates of den entry, den emergence, and parturition were unrelated to weather and hard mast production. / Master of Science / incomplete_metadata

Ecology and physiology of black bears in Great Dismal Swamp (GDS) National Wildlife Refuge and surrounding area, a forested wetland in eastern Virginia and northeastern North Carolina, were studied from April 1984 to March 1987. A total of 101 bears (71M, 30F) were captured 120 times. Males dominated the capture sample (<u>P</u>< 0.001), but age did not differ between sexes (<u>P</u>= 0.74). Mean (±SE) age was 4.2±0.3 years. Litter size (<i>x̅</i>=2.1; N=12), modal age at primiparity (4 years), and interbirth interval (slightly greater than 2 years) were indicative of good-quality habitat. Estimated annual adult survival rates were 0.84 for females and 0.58 for males. Causes of mortality included legal (outside the Refuge) and illegal harvest, vehicle collisions, depredation permit kills, research, and predation. Population density for the study area was estimatcd by 6 techniques at 0.47-0.68 bears/km², corresponding to 262-377 bears for the 555 km² study area. Demographic data suggested a stable and productive population. Three major levels of diet quality were observed in terms of crude fiber, fat, and protein. Spring diets were high in protein but moderate in crude fiber, while fall diets were low in crude protein and high in ether extract. Condition indices and several blood characteristics (e.g. total protein, albumin, HCT, hemoglobin, and RBC) were at peaks in spring and late fall and at a low during summer. Serum creatinine concentrations also varied seasonally (<u>P</u><0.001), with a peak during denning and high levels in spring and late fall, perhaps resulting from transition from and to hibernation. A urea/creatinine (U/C) ratio ≤10 was not a good indicator of the hibernating state, as 39 of 120 (32.5%) trapped, active bears had U/C ratios ≤10. Creatinine and total protein were the best indicators of the hibernating state. Albumin, HCT, hemoglobin, and RBC were the best indicators of condition during active stages, as indicated by significant (<u>P</u>< 0.1) correlations of condition indices and blood variables. Nine blood variables varied with age (<u>P</u>< 0.1). Multivariate analysis of variance and discriminant function analysis using blood variables failed to reject the hypothesis that bears cycled through 4 metabolic stages throughout the year. Results showed that metabolic shifts were tied to concomitant seasonal changes in diet quality, diet composition, and body condition, but also may have an endogenous component. Habitat and range use dynamics were described by radiotracking of 24 female and 22 male bears. Median annual range size estimates were 79.1 km² for males (<u>N</u>=10), 33.1 km² for subadult h females (<u>N</u>=7), and 21.4 km² for adult females (<u>N</u>=11). Preferred (<u>P</u>< 0.05) habitats on an annual basis were pocosins and mesic areas for females and gum-cypress and maple-coniferous stands for males. Seasonally, pocosin, gum-cypress, mesic, and disturbed areas were important for females. Bear distribution analysis indicated that roads were preferred (<u>P</u>< 0.05) during all seasons except early fall, when bears made fall excursions to feeding areas far from Swamp roads and close to the study area boundary. Range overlap was extensive for both sexes, although it appeared that females maintained exclusive ranges during spring and early summer. Denning ecology was described by monitoring 35 bears (26F, 9M). Five bears (2M, 3F) remained active throughout the winter. Den types included 14 elaborate ground nests, 11 excavated ground cavities, 2 ground-level tree cavities, 1 above-ground-level tree cavity, and l den in a stump. Females with cubs denned earlier, (<u>P</u>< 0.02) emerged later (<u>P</u>< 0.001), and denned longer (<u>P</u>< 0.001; 119 ±4 days vs. 78 ±4 days) than all other bear groups. Dry den sites did not appear to be limited. Present population management (protection from hunting and no public vehicular access) should be continued in the Refuge. The small effective population size (N=66) in GDS indicated the need for study of dispersal and genetics in the GDS and other southeastern wetland populations to determine the degree of isolation and extent of genetic variability. Maintenance and enhancement of pocosins, mature gum, oak, and disturbed habitats would benefit black bears in southeastern wetlands by providing a wide variety of natural foods throughout the year. Large den trees may not be necessary for successful denning and reproduction in certain southeastern wetlands because bears can use dense cover and microelevational factors to overwinter. Black bear conservation strategies in the Southeast are a critical need due to increasing habitat fragmentation. Six adult female black bears were maintained in captivity in Virginia from August 1987 to April 1988. Serum samples, as well as data on body weight and rectal temperatures, were collected from each bear at approximately 10-day intervals from 25 September to 30 March. Four of the six bears hibernated, not feeding for periods of 56 to 121 days (<i>x̅</i>=94 d). Rectal temperature declined in both active and hibernating bears during winter, but to a greater extent (P= 0.013) in hibernators. Average weight loss during hibernation represented 27.9% of peak body weight. Mean serum urea/creatinine (U/C) ratios were similar between physiological groups during the prehibernation phase. However, U/C ratios differed (<u>P</u>< 0.025) after the onset of hibernation. Concentrations of total serum protein, serum urea nitrogen, and serum creatinine were similarly affected by significant time-group interactions (<u>P</u>< 0.01). Alkaline phosphatase, phosphorus, sodium, and chloride changed significantly (<u>P</u>< 0.05) during the course of the experiment, without regard to physiological group. U/C ratio was a good indicator of the hibernating state, but the sensitivity of serum urea levels to diet suggests careful use of U/C ratio as a field index. Serum progesterone (P) concentrations slowly increased from 2 to 5 ng/ml during October and November, then increased 2-2.5 fold 58 ±5 days before parturition in 2 bears that produced cubs. After the implantation peak, P declined, reaching undetectable levels 1-2 days postpartum. Similar P profiles were observed in 3 of 4 bears that did not produce any observed cubs. P also was assayed in 38 active wild black bears to relate to reproductive status in the den. Changes in serum estradiol-17<i>ß</i> concentrations during gestation also were profiled. The occurrence of pseudopregnancy or early embryonic mortality in bears with elevated serum progesterone concentrations is discussed. / Ph. D.

Thesis (M.S.)--University of Tennessee, Knoxville, 2009. / Title from title page screen (viewed on Mar. 8, 2010). Thesis advisor: Frank T. van Manen. Vita. Includes bibliographical references.

No description available.