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Gewählte Master / Diploma Thesis:

Christine Reusch (2013): Habitat segregation in the brown bear (Ursus arctos): testing the predation risk hypothesis.
Master / Diploma Thesis - Institut für Wildbiologie und Jagdwirtschaft (IWJ), BOKU-Universität für Bodenkultur, pp 127. UB BOKU obvsg

Data Source: ZID Abstracts
Abstract:
Habitat segregation implies a different habitat use by sexes and/or reproductive classes within a species. One hypothesis to explain habitat segregation is the predation risk hypothesis: females with dependent offspring try to reduce the predation risk, to assure the survival of their progeny. Predation risk in carnivores often is related to intraspecific infanticide, the by conspecifics caused death of an infant. Sexually selected infanticide (SSI) describes infanticide as a male strategy to increase chances of mating, and could result in predator avoidance by females with dependent offspring. In a Scandinavian brown bear population strong evidence for habitat segregation and SSI exists. We examined if there are nutritional differences between reproductive classes (females with cubs of the year (FC), receptive females (RF), and adult males (AM)) in accordance with the SSI hypothesis and the predation risk hypothesis in this population. We used the fecal nutritional value as a proxy for food and habitat quality. We used near-infrared spectroscopy to analyze the contents of crude fat, crude protein, crude fiber, crude ash, lignin, ADF, and NDF in fecal samples, collected in 2010. Additionally, we visually estimated volume percentage of food items in feces. We predicted that FC would show a lower nutritional value during the breeding season than RF and AM. In the post-breeding season the nutritional value of feces among FC, AM and RF should be more or less similar. The diet quality of AM and RF should stay about the same between both seasons. The results revealed that the nutritional values and food items differed between seasons and reproductive classes. The food items significantly affected nutritional components in feces. Our results suggest that habitat segregation between FC and AM/RF in the breeding season in the Scandinavian brown bear population is probably a consequence of SSI.

Beurteilende(r): Hackländer Klaus
1.Mitwirkender: Zedrosser Andreas

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