Scholarship & Research
Permanent URI for this communityhttps://scholarworks.montana.edu/handle/1/1
Browse
4 results
Search Results
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 Wolverine habitat quality, connectivity, and prioritization at the landscape scale(Montana State University - Bozeman, College of Letters & Science, 2019) Carroll, Kathleen Anne; Chairperson, Graduate Committee: Andrew J. Hansen; Andrew J. Hansen, Robert M. Inman and Rick L. Lawrence were co-authors of the article, 'Comparing methods to disentangle habitat predictors for wolverines in the southern extent of their distribution' which is contained within this dissertation.; Andrew J. Hansen, Robert M. Inman, Rick L. Lawrence and Andrew B. Hoegh were co-authors of the article, 'Testing landscape resistance layers and modeling connectivity for wolverines in the western US' which is contained within this dissertation.; Robert M. Inman, Andrew J. Hansen, Kevin Barnett and Rick L. Lawrence were co-authors of the article, 'Prioritizing metapopulation connectivity for wolverines' which is contained within this dissertation.The core of conservation biology is understanding how to mitigate the impacts of anthropogenic activities on species. These impacts are particularly detrimental to isolated and small populations, which face extirpation or extinction without immediate conservation action. For small and isolated populations, protecting connective habitat (e.g., corridors) and facilitating movement is key. Corridor identification requires rigorous planning and appropriate statistical choices to ensure that resulting conservation actions are defensible and best support ecological processes. This manuscript asks: 1) how do different, commonly used statistical methods inform our understanding of species resource selection across scale and between sexes, 2) how does landscape resistance and connectivity differ between resident and dispersing individuals, and 3) what information is important to include in a systematic conservation plan to best support on-the-ground conservation between land trusts, landowners, and other practitioners under future climate change conditions. To address each of these questions we focused on wolverines (Gulo gulo), which exist as isolated metapopulations across the western contiguous United States. Our key findings included that 1) the importance of habitat variables differ only slightly by sex, across selection scales, and across analysis methods, 2) dispersing animals are less sensitive to habitat quality compared to resident animals, and 3) including information that both helps mitigate potential threats and preserves ecological processes is the best approach for connectivity conservation planning. This work represents the most comprehensive wolverine connectivity conservation analyses to date. This research suggests that examining multiple approaches and validating results is critical to generating rigorous and defensible conservation decisions are being made for wolverines, although more studies are needed to validate this in other species. Taken together, this research provides land managers, policy makers, and scientists with guidance for future connectivity analyses, conservation action for wolverines, and a research framework that can be applied to additional species of conservation concern in isolated populations.Item Testing the effects of anthropogenic pressures on African lions and their prey in the Greater Kafue Ecosystem, Zambia(Montana State University - Bozeman, College of Letters & Science, 2020) Vinks, Milan Alexander; Chairperson, Graduate Committee: Scott Creel; Scott Creel, Paul Schuette, Wigganson Matandiko, Elias Rosenblatt, Carolyn Sanguinetti, Kambwiri Banda, Ben Goodheart, Matthew S. Becker, Clive Chifunte, and Chuma Simukonda were co-authors of the article, 'Testing the effects of anthropogenic pressures on a diverse African herbivore community' in the journal 'Ecosphere' which is contained within this thesis.; Scott Creel, Paul Schuette, Matthew S. Becker, Elias Rosenblatt, Carolyn Sanguinetti, Kambwiri Banda, Ben Goodheart, Kim Young-Overton, Xia Stevens, Clive Chifunte, Neil Midlane, and Chuma Simukonda were co-authors of the article, 'Response of lion demography and dynamics to the loss of prey and changes in prey community composition' submitted to the journal 'Ecological Applications' which is contained within this thesis.Rapid human population growth across Africa has put tremendous pressure on large herbivore and large carnivore populations, and most of these large terrestrial species are now limited to residing within or adjacent to protected area (PA) networks. However, high rates of human encroachment and associated activities around and within PAs are jeopardizing their effectiveness and have become a major conservation concern. High rates of illegal harvest are linked to human encroachment and can have devastating effects on large herbivore and large carnivore populations. Large herbivore declines are often greatest in areas with high rates of illegal offtake and ensuing prey depletion can be a primary driver of large carnivore declines. Kafue National Park (KNP) of central Zambia supports a diverse large herbivore community and the country's second largest lion population. However, KNP is thought to be experiencing human-caused wildlife declines, providing a unique opportunity to evaluate anthropogenic effects on both the large herbivores and large carnivores of this system. Here, we evaluated the status and major anthropogenic and environmental drivers of KNP's large herbivore populations and lion population. First, we estimated population densities and distribution of the ten most abundant large herbivore species using stratified ground-based surveys conducted from 2012 - 2018. These data indicated that population densities were consistently low across species and areas, though there was ecologically important variation among species and size classes. Moreover, densities of larger-bodied herbivores were greatly depressed relative to smaller species. Second, we evaluated population density, survival rates, and demography for the KNP lion population from 2013 - 2018. These data indicated that age- and sex-specific survival rates for settled individuals were generally high, and factors known to correlate with local prey density had small effects on lion survival. In contrast, average lion density was low and recruitment of cubs was poor. These findings suggest that low recruitment might be a better signal of low prey density than survival. Overall, large herbivores and lions appear to be limited by human activities in KNP. Increased resource protection and reducing the underlying drivers of prey depletion are urgent conservation needs to facilitate the recovery of these economically and ecologically valuable species.Item Impacts of human activity on bighorn sheep in Yellowstone National Park(Montana State University - Bozeman, College of Letters & Science, 1998) Ostovar, Kayhan; Chairperson, Graduate Committee: Lynn R. IrbySeventeen years have passed since bighorn sheep (Ovis canadensis canadensis) in Yellowstone National Park (YNP) experienced a massive Chlamydial-caused die-off. Currently, no sign of Chlamydia or pneumonia is evident, thus other factors are considered to be limiting the population. The proposed changes to the Gardiner-Mammoth highway and the highway through Dunraven Pass could increase or decrease human disturbances to the core population of bighorn sheep. Approximately 65% of all observations on the Everts winter range occurred on the top of McMinn Bench (along the proposed road route). One ewe group currently must cross the Gardiner-Mammoth highway to reach spring lambing grounds. The placement of the road onto McMinn Bench would impact at least 2 other populations of ewe groups and 2-3 populations of ram groups, which seek shelter, security, water, and minerals in the cliffs.