Theses and Dissertations at Montana State University (MSU)
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Item Evaluating bear management areas in Yellowstone National Park(Montana State University - Bozeman, College of Letters & Science, 2022) Loggers, Elise Ahlenslager; Chairperson, Graduate Committee: Andrea Litt; This is a manuscript style paper that includes co-authored chapters.A growing body of research suggests large predators change their behavior near humans in ways that parallel how prey respond to predators; when outdoor recreation increases, avoiding humans becomes more difficult. Restricting human access to reduce detrimental effects of human-wildlife interactions can be an attractive management tool, however, rarely is the efficacy of such measures assessed. In 1982, Yellowstone National Park began instituting short-term, annual restrictions to areas of the backcountry containing important food resources for grizzly bears (Ursus arctos). These areas -- Bear Management Areas (BMAs) -- were intended to reduce human-caused disturbance of foraging bears and improve visitor safety. We sought to assess whether grizzly bears: 1) preferred BMAs with access restrictions more than other areas in YNP and 2) changed their response to sporadic (trail) and predictable (campsite) recreation sites depending on BMA access restrictions. We modeled resource selection of grizzly bears with step-selection functions, based on GPS locations from male and female bears collected from 2000 to 2020. Our analyses demonstrated that grizzly bears differentially selected BMAs, compared to areas outside BMAs, and that selection changed with sex and season. Bears likely prefer BMAs for the resources they contain more than to avoid people as only males changed their selection of BMAs based on access restrictions. Males avoided hiking trails during the day, but preferred trails at night. Females changed their selection of trails depending on human access restrictions and avoided trails in unrestricted BMAs. Combined with previous work, results suggest bears capitalize on the environment to avoid human presence, often with sex-specific strategies. For sporadic recreation, males temporally avoid the perceived risk of people whereas females spatially avoid the perceived risk of people. Although lower-intensity activities often are thought of as compatible with conservation, such recreation may be cryptic, but important, drivers of behavioral change in wildlife.Item Varying nonlinear dependencies in habitat selection: estimating instead of imposing functional forms(Montana State University - Bozeman, College of Letters & Science, 2016) Ebinger, Michael Ryan; Chairperson, Graduate Committee: Robert A. GarrottSpatial heterogeneity of habitats and different foraging strategies can result in dissimilar patterns of habitat selection among individuals in a population. Studies have demonstrated that incorporating individual variation can influence model inferences. Thus, individual variation is increasingly being incorporated in habitat selection studies. Our objective was to advance the concept of individual variation in habitat selection by incorporating varying shapes (i.e., function forms) of responses among individuals. We used simulation modeling to develop a new analytical framework and introduce a new habitat selection metric, the Normalized Selection Ratio (NSR). Our results demonstrated the ability of the NSR to correctly estimate the strength and shape of complex simulated patterns of habitat selection, while simultaneously protecting against over-fitting. Using a simulated population of individuals, we showed how our approach can scale-up individual responses to facilitate population-level inference. We demonstrated how hierarchical clustering of individual-level response curves can identify and quantitatively describe different types of habitat selection within a population. When applied in a temporally dynamic framework, we showed that the NSR can detect ecological dynamics in habitat selection with quantitatively different inferences from analyses that pool data over time. We illustrated application of our approach using global positioning system (GPS) telemetry data for grizzly bears (Ursus arctos) in the Greater Yellowstone Ecosystem (GYE). We investigated the direction (preference or avoidance) and shapes of grizzly bear selection for whitebark pine (Pinus albicaulis) habitat during fall from 2007 to 2014. Our general conclusions support previous findings that grizzly bears exhibit a high degree of individual variation in habitat selection. Our approach of hierarchically clustering response curves detected 4 groups of grizzly bears with distinctly different patterns of whitebark pine habitat selection. Based on the group-level mean responses, 77% of sampled bears selected for whitebark habitat and 23% selected for non-whitebark pine habitats. Among the hierarchical groups that selected for whitebark pine, we observed substantial variation in the strength and density of whitebark pine being used. These results demonstrated the ability of our approach to identify, quantify, and organize individual differences in habitat selection and improve our understanding of grizzly bear ecology in the GYE.Item Grizzly bear and human interaction in Yellowstone National Park : bear management areas(Montana State University - Bozeman, College of Letters & Science, 2012) Coleman, Tyler Hardy; Chairperson, Graduate Committee: Scott Creel; Charles C. Schwartz, Kerry A. Gunther and Scott Creel were co-authors of the article, 'Grizzly bear and human interaction in Yellowstone National Park; an evaluation of bear management areas' submitted to the journal 'Journal of wildlife management' within this thesis.; Charles C. Schwartz, Kerry A. Gunther and Scott Creel were co-authors of the article, 'Influence of overnight recreation on grizzly bear movement and behavior in Yellowstone National Park' submitted to the journal 'Ursus' which is contained within this thesis.; Charles C. Schwartz, Kerry A. Gunther, Scott Creel were co-authors of the article, 'Displacement behavior of grizzly bears following direct interactions with backcountry users in Yellowstone National Park' which is contained within this thesis.; Charles C. Schwartz, Kerry A. Gunther, Scott Creel were co-authors of the article, 'Grizzly bear activity patterns and the influence of human presence' which is contained within this thesis.In 1982 Yellowstone National Park, WY, USA created a Bear Management Area (BMA) program. The objective of the BMA program was to minimize human-bear conflict by separating bears from people in areas of the Park where overlap may occur. This was accomplished primarily through area closures, trail closures, and backcountry campsite closures. Our objective was to evaluate the interaction between grizzly bears and people and use the results to test the effectiveness of the BMA program. From 2007 to 2009, we obtained fine scale human and grizzly bear GPS data in 6 of 16 BMAs. To determine how grizzly bears responded to close interactions with people, we evaluated the GPS locations of bears and people in close proximity. We found that bears consistently avoided human interaction and often showed an avoidance response to people at close distances. We also evaluated spatiotemporal patterns of bear and human movements during times when BMAs were restricted (closed to human use) and unrestricted (open to human use). Through the comparison of the two time periods we found that bears continued to avoid people on a large scale. Furthermore, a significant amount of overlap between people and bears would occur if BMA restrictions were not in place. We also evaluated the effectiveness of backcountry campsite closures by testing if grizzly bears were attracted to, or avoiding occupied backcountry camps. We found that grizzly bears were attracted to the location of backcountry campsites, however there was a strong avoidance when these sites were occupied by people. Finally, we evaluated the behavioral and activity adaptations of bears occupying areas frequently used by people. We found that bears were primarily more night active and less day active when near areas that humans use. In addition, we found that if BMA restrictions did not exist, we could expect overlap between bears and people when both were highly active. Overall, our results suggest that grizzly bears consistently avoid contact with humans and that the BMA program in Yellowstone National Park is effective at reducing human-bear overlap, potential conflict, and reducing displacement of bears by humans.