Movement of organisms is a fundamental component of many ecological processes, and should be subject to strong selective pressures. Spatial selection is the process by which individuals choose the locations to acquire necessary resources or avoid risk, and the relative importance of different factors on spatial selection may change depending on the scale being analyzed. Under the framework of optimality, an individual should attempt to structure their spatial selection economically to maximize fitness. I studied black bear (Ursus americanus) space use, habitat selection, and movement under the optimality paradigm in three populations (Michigan, Missouri, and Mississippi) at four different scales: regional, annual home range, seasonal home range, and denning sites. At the regional scale, I found that black bears displayed scale-dependent land cover selection for movement, selecting forested areas at coarser scales and avoiding anthropogenic disturbance at finer scales, and that large contiguous forests and riparian corridors most facilitate connectivity among protected areas. At the annual and seasonal home range scales, I found black bears display scale-dependent optimizing strategies. Individuals locating their annual ranges to maximize access to areas of high vegetation productivity, together with the high productivity of ranges of all sizes, suggests an energy maximizing strategy, while the negative relationship between range size and both fragmentation and forest proportion suggests area minimizing. More limiting factors act at larger scales, which suggests productivity is the strongest limiting factor and energy maximizing is the dominant strategy while plasticity allows for seasonal area minimizing. At the den site scale, I found that both female and male black bears appeared to minimize anthropogenic risk during denning; however female black bears have a flexible response to anthropogenic disturbance, attempting to minimize it when alone or with older offspring, yet having increased tolerance when infanticide is greater after cubs are born and following den emergence. By quantifying black bear space use and selection across multiple scales, diverse areas, over time, and among and within individuals, I revealed consistent scale-dependent responses to environmental and biological factors while highlighting the intrinsic plasticity of this flexible omnivore.
| Identifer | oai:union.ndltd.org:MSSTATE/oai:scholarsjunction.msstate.edu:td-4246 |
| Date | 10 August 2018 |
| Creators | Gantchoff, Mariela Gisele |
| Publisher | Scholars Junction |
| Source Sets | Mississippi State University |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | Theses and Dissertations |
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