Thesis (M.E.S.)--York University, 2000. Graduate Programme in Environmental Studies. / Typescript. Includes bibliographical references (leaves 137-144). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://wwwlib.umi.com/cr/yorku/fullcit?pMQ59551.

Vancouver Island marmots (M. vancouverensis) rank among the world's most critically endangered mammals. There were probably fewer than 100 marmots in 1998, with 90% distributed south of Alberni Inlet, and the remainder on or near Mount Washington. This represents a 60–70% decline in numbers during the past 10 years, and a considerably reduced geographic range during the past several decades. I used data from marked animals, radio-telemetry and population counts to test whether population dynamics were consistent with predictions made under five hypotheses: habitat tracking, sink-connectivity, weather, predators and disease. Estimates of demographic rates from intensive mark-recapture work and population counts were generally consistent, although estimation of adult survival from counts was problematic because of the difficulty of distinguishing surviving marmots from immigrants. There was no apparent influence of mark-recapture on survival or reproduction, and intensively studied colonies showed similar dynamics to colonies that were visited infrequently. There was little evidence for habitat tracking in natural habitats. Few colonies showed chronically low reproduction or survival, which would be the predicted result of a gradually deteriorating environment. Declines were more often abrupt and catastrophic. Marmots did not colonize clearcuts in proportion to their temporal or spatial availability, and ultimately colonized only a minuscule fraction of the potential habitat. However, marmots already inhabiting clearcuts represent a special case of habitat tracking; survival rates were significantly lower at clearcuts of more advanced seral age (i.e., >11 years after harvest). Evidence for source-sink and landscape connectivity processes was relatively strong. Marmots inhabiting clearcuts had chronically lower survival rates (by 5–10%). Per female reproductive contribution in clearcuts was half that of females inhabiting natural environments. However not all clearcuts acted as sinks, or acted as sinks in all years. Colonizations of clearcuts were spatially concentrated and none occurred at distances greater that 5 km from an existing natural colony. Apparent adult survival was significantly associated with isolation but juvenile survival was not, which is consistent with the prediction that isolated colonies should receive fewer immigrants. However the spatial pattern of extinctions was unexpected. Isolated and closely-clustered colonies had similar probabilities of extinction. Weather significantly influenced marmot survival and reproduction but explained only small amounts of variation. Survival was significantly associated with rainfall, temperature and snowpack depth. Reproduction was negatively associated with snowpack and temperature. Slope aspect was significantly associated with survival, perhaps suggesting the importance of snowmelt patterns. Natural and clearcut colonies responded differently to weather. Indices of wolf and cougar abundance were inconsistent and probably do not reflect true population sizes. Deer abundance was weakly associated with marmot survival in natural habitats, which could suggest switching of predator hunting effort. Marmot survival was spatially correlated, which is consistent with the idea that a few individual predators may focus hunting efforts at adjacent colonies. Field observations and radio-telemetry corroborated the importance of predators. In natural habitats, disappearances were uniformly distributed throughout summer, as predicted. In clearcuts, disappearances, were more heavily skewed towards late summer, suggesting that winter mortality was more important. Spatial correlation of survival is also consistent with the disease hypothesis. Survival was lower in colonies with high relative density of adults, which is a predicted result given the prediction of increased risk of disease transmission. The incidence of high mortality events increased during the 1990s, and the degree of spatial correlation also increased despite a more fragmented population structure. These trends are consistent with a hypothesis of a new disease organism or increased risk of infection. Forestry appears to be the primary cause of recent population dynamics in the Nanaimo Lakes region. Logging reduced overall marmot survival, inhibited their ability to re-colonize sites, and concentrated the population, making colonies more susceptible to predators and disease. The prognosis for continued survival remains hopeful provided that current plans for captive-breeding and captive-breeding and reintroduction are pursued aggressively. / Graduate

Thesis (M.S.)--Texas State University-San Marcos, 2008. / Vita. Appendix: leaves 73-89. Includes bibliographical references (leaves 90-93). Also available on microfilm.

Thesis (M.S.)--Oregon State University, 2004. / Typescript (photocopy). Includes bibliographical references (leaves 102-112). Also available on the World Wide Web.

Thesis (M.S.)--University of West Florida, 2007. / Title from title page of source document. Document formatted into pages; contains 117 pages. Includes bibliographical references.

Thesis (M.S.) in Marine Policy--University of Maine, 2009. / Includes vita. Includes bibliographical references (leaves 68-76).

Thesis (M.S.)--Brigham Young University. Dept. of Plant and Wildlife Sciences, 2008. / Includes bibliographical references.

No description available.

No description available.

Cape mountain zebra habitat utilization and diet in the dystrophic fynbos habitat of the Bontebok National Park was found to be highly selective. Mountain zebra concentrated in specific sectors and habitat types in the park on a seasonal basis, preferring recently burnt habitat with a veld age younger than one year in all seasons, except during the warm, dry summer. Proteoid Fynbos with a veld age between one and five years was preferred in the cool winter, while Drainage Lines and the fringes of Inland Pans were preferred during summer. Asteraceous Fynbos was avoided, irrespective of veld age, as well as all other habitats with a veld age greater than five years. Within habitat types with a veld age greater than one year, specific sites were selected and avoided on a seasonal basis, which were found to differ in terms of habitat suitability, based on the availability of dietary plant species. The annual diet consisted of 72.6% grass, 11.8% restio, 5.9% sedge, 8.8% geophyte and less than 1% forb and shrub species. Three grass species formed the bulk of the annual diet, Themeda triandra, Cymbopogon marginatus and Eragrostis curvula, for which leaf use was greater than stem use. Themeda trianda was preferred throughout the year, but contributed to the diet in greatest proportion in the warm, dry summer, when it was available at greatest leaf height and diameter. Cymbopogon marginatus was preferred during the cool winter, when diet composition and greenness was also greater than in other seasons. Preference of Cymbopogon marginatus decreased as leaf height and diameter increased. Eragrostis curvula was preferred in the warm autumn, when it composed the largest proportion of the diet, and selection of this species at feeding sites was based on both greenness and volume. In summer mountain zebra also preferred grass stems and inflorescences of Aristida diffusa, Stipagrostis zeyheri and Briza maxima. During the cool spring the diet included stems and inflorescences of sedges and restios, primarily Ischyrolepis capensis, and in autumn, dry bulbs of the geophyte Moraea collina were utilized. Habitat utilization, as well as grass height and greenness surveys in the Recently Burnt Area, and the nutritional status of mountain zebra was found to be in line with the Summer Nutritional Stress Hypothesis. The hypothesis proposes that the harsh climatic conditions of the area during summer are linked to the low availability of C4 grass, on which grazers would depend in summer. This is supported by the avoidance of the Recently Burnt Area in summer, and the preference of species like Themeda triandra during summer despite low greenness levels. Faecal nitrogen and phosphorus for mountain zebra in Bontebok National Park and De Hoop Nature Reserve were at minimum levels during the warm seasons. Faecal nitrogen was below the threshold for dietary deficiency in all seasons except spring, and faecal phosphorus was above the threshold for deficiency during two seasons only. The findings of this study are in line with other recent work on mountain zebra in the Baviaanskloof suggesting that, due to a high required rate of forage intake, mountain zebra are limited by both poor resource quantity and quality in dystrophic fynbos ecosystems.