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Item Snowshoe hare habitat use and silvicultural influences in the Greater Yellowstone Ecosystem(Montana State University - Bozeman, College of Agriculture, 2019) Kurzen, Mark Daniel; Chairperson, Graduate Committee: Bok SowellSnowshoe hares (Lepus americanus) are the main prey base of the Canada lynx (Lynx canadensis) and are an important food source for many forest carnivores. Snowshoe hare research in the Greater Yellowstone Ecosystem is lacking and current research conclusions differ in regards to the types and ages of forests that snowshoe hares prefer. The US Forest Service has implemented limitations and prohibitions on silviculture in this area based on previous snowshoe hare studies. However, some research in the Greater Yellowstone Ecosystem suggests that regenerating lodgepole pine (Pinus contorta) stands that are associated with silviculture benefit snowshoe hares. We implemented three snowshoe hare use indices in southwest Montana within a portion of the Custer-Gallatin National Forest during 1999-2012 to assess snowshoe hare use of forest cover types in Greater Yellowstone Ecosystem. Our study area was located in a designated US Forest Service timber management area where a history of silviculture has resulted in a heterogeneous landscape of multiple successional stages intermingled with other old growth stands. We analyzed 11 years of snowshoe hare pellet plot surveys using linear mixed models and AIC c model selection. Our results suggested that the understory conifer species was the best predictor of use and that the youngest two classes of regenerating lodgepole pine stands had the greatest snowshoe hare use. We analyzed 13 years of snowshoe hare track counts on roads within our study area using Chi-squared goodness-of-fit tests based on proportional road segment lengths and the associated cover types. We observed the greatest snowshoe hare habitat use in the youngest two classes of regenerating lodgepole pine stands. We live-trapped snowshoe hares for one winter in our study area and observed the greatest number of hares captured per night in the youngest lodgepole pine stands. The findings from our 13 year study suggest that snowshoe hare use was greatest in early successional lodgepole pine forests that were approximately 30-60 years old and associated with clear cutting and pre-commercial thinning.Item Livestock depredation by grizzly bears on Forest Service grazing allotments in the Greater Yellowstone Ecosystem(Montana State University - Bozeman, College of Agriculture, 2017) Wells, Smith Laura; Chairperson, Graduate Committee: Lance McNewGrizzly bear population growth and range expansion over the last several decades in the Greater Yellowstone Ecosystem (GYE) has led to increased human-bear conflicts, including livestock depredation on public land grazing allotments. A better understanding of patterns and relationships between grazing allotment management and grizzly bear depredation of livestock is needed for adaptive, sustainable management in the ecosystem. Historic U.S. Forest Service and National Park Service livestock grazing records, grizzly bear habitat attributes, and documented livestock depredations by grizzly bears were collated for 316 public land grazing allotments within the grizzly bear Demographic Monitoring Area (DMA) during 1992-2014. Spatio-temporal relationships between annual livestock depredation counts and grazing allotment characteristics were modeled for each allotment during the study period at two spatial extents, representing daily and annual grizzly bear activity areas. As the Yellowstone grizzly population expanded during the last several decades, more public land grazing allotments were exposed to potential livestock-grizzly bear interactions and results indicated that both livestock stocking and grizzly bear habitat characteristics in and around allotments were related to documented depredations during 1992-2014. Annual numbers of livestock and grizzly bear density on allotments had a large, positive effect on average livestock depredation event counts. Allotment size and summer grazing both were related to higher depredation event counts while the presence of bulls and/or horses was related to lower counts. Allotments with less rugged terrain, lower road density, relatively higher vegetative primary productivity, greater amounts of whitebark pine, and further from forest edge on average were associated with higher average livestock depredation event counts. Managers and livestock producers could use these results to support adaptive management approaches and long-term planning such as increasing herd supervision, especially in areas with quality grizzly bear habitat and high grizzly bear density, or altering grazing management strategies and grazing locations to limit potential livestock depredation events. Results provide insight into historic livestock-grizzly bear conflicts on public lands in a large, complex ecosystem and although challenging, results could support cooperative management strategies to sustain the grizzly bear population and livestock operations in the GYE.Item Effects of livestock grazing management on the ecology of grassland birds and their predators in a northern mixed-grass prairie ecosystem(Montana State University - Bozeman, College of Agriculture, 2018) Vold, Skyler Thomas; Chairperson, Graduate Committee: Lance McNew; Lance B. McNew and Lorelle I. Berkeley were co-authors of the article, 'Effects of livestock grazing management on the ecology of grassland birds in a northern mixed-grass prairie ecosystem' submitted to the journal 'Rangeland ecology & management' which is contained within this thesis.; Lance B. McNew and Lorelle I. Berkeley were co-authors of the article, 'Effects of livestock grazing management on the occupancy of mesocarnivores in a northern mixed-grass prairie ecosystem' submitted to the journal 'The journal of wildlife management' which is contained within this thesis.Grassland birds have recently undergone substantial population declines throughout much of their historic ranges in North America. The majority of remaining grassland bird habitat is rangeland managed for livestock production, so grazing management has implications for grassland bird conservation efforts. Populations of mesocarnivores have recently seen range expansions and increased abundance as a result of anthropogenic extirpation of apex predators in grassland ecosystems. Mesocarnivores are often major predators of grassland birds and their nests, so considering the effects of management actions on mesocarnivore occupancy is important within grassland bird conservation efforts. I evaluated the relative effects of three livestock grazing systems on grassland bird abundance and mesocarnivore occupancy in a northern mixed-grass prairie ecosystem of eastern Montana, USA. During 2016-17, I conducted replicated point-count surveys at 150 locations on a 3,000-ha ranch managed with rest-rotation cattle grazing, and 155 locations on adjacent reference properties (4,300-ha) employing season-long or 2-pasture summer-rotational grazing systems to identify grazing management influences on grassland bird abundances. During 2016-17, I deployed remote cameras at 45 locations within rest-rotation grazing systems, and at 45 locations on reference properties to identity grazing management influences on mesocarnivore occupancy. Overall, there was no noticeable benefit of rest-rotation grazing on abundance or species diversity of grassland birds relative to season-long and summer-rotation grazing systems. Species-specific responses to livestock grazing system were found for each of three obligate grassland birds. Support for interactions between grazing system and local rangeland production potential were found, limiting the ability to recommend general livestock management practices for the benefit of grassland bird populations. Additionally, abundance of grasshopper sparrow (Ammodramus savannarum; beta = -0.10 + or = 0.03) and western meadowlark (Sturnella neglecta; beta = -0.09 + or = 0.03) showed a negative relationship with increasing stocking rate. Occupancy of mesocarnivores was highest in rest-rotation grazing systems, followed by season-long and summer-rotation systems, respectively, and showed a positive relationship with increasing stocking rate (beta = 1.64 + or = 1.10). Regional guidelines for livestock grazing management may be inappropriate in terms of grassland bird conservation efforts in the northern mixed-grass prairie.