| Summary: | Conservation of predators that have been reintroduced to their native range can be improved through studies of their demographic rates, resource use, and activity patterns. I studied American martens (Martes americana ) and fishers (Martes pennanti) in northern Wisconsin, USA, where they were reintroduced following extirpation in the 1930s. Fisher populations have increased since reintroduction, but marten populations have not increased. In my first chapter, I studied marten survival. Results indicate that low survival of adult martens has not limited their reestablishment in Wisconsin and that fisher and raptor kills had only a moderate impact on adult marten survival. In my second chapter, I studied marten and fisher resource use within their home ranges during winter. Areas dominated by eastern hemlock (Tsuga canadensis) and northern white cedar (Thuja occidentalis) contained more use sites (i.e., rest and kill sites) than was expected. Martens also selected the hemlock-cedar cover type along their movement paths, and hemlock-cedar is where they moved most sinuously and oriented least efficiently toward rest sites. Martens may have concentrated their activities in hemlock-cedar because they found rest sites and small mammal prey there, and small mammals sustain their energetic demands. Despite a greater number of use sites in hemlock-cedar, fisher path sinuosity, orientation efficiency, and selection metrics did not vary by cover type. Fishers rested in hemlock-cedar but may require larger prey typically found in other cover types to sustain their energetic demands, such as snowshoe hares ( Lepus americanus). In my third chapter, I studied patterns of marten and fisher activity during winter. Results from activity monitoring are consistent with the hypothesis that marten and fisher activity is motivated by prey availability. The poor predictive ability of my final models indicated that activity levels are motivated by multiple factors and/or factors other than environmental conditions and gender. In my last ...
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