Theses and Dissertations at Montana State University (MSU)
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Item Long-term response of willow to beaver reintroduction and moose browsing in the southern Absaroka-Beartooth Wilderness(Montana State University - Bozeman, College of Agriculture, 2022) Dines, Rachael Helen; Chairperson, Graduate Committee: Bok SowellWillow is an important component in the southern Absaroka Beartooth Wilderness (ABW) riparian areas because it provides critical beaver habitat and is an essential food source for moose populations. Forest Service managers have monitored long-term trends in willow condition and herbivore populations in the southern ABW. Beavers were extirpated in the mid-1900's and then reintroduced beginning in 1986. Moose numbers increased in the early 1900's and willow over-browsing followed until the population declined after habitat loss from the 1988 Yellowstone fires. The objective of this study was to examine willow condition in response to changes in beaver and moose populations in the southern ABW. I used annual stream-side surveys to record the number and location of beaver colonies from 1986 to 2021 and aerial imagery to describe changes in willow canopy cover. I used a binomial regression to evaluate the relationship between willow canopy cover and beaver colony density and longevity to estimate if long-term beaver presence increased willow canopy cover. I used linear regression to analyze indices of moose relative abundance, willow plots recording height and browsing, and a long-term browsing exclosure to evaluate the effect of moose population trends on willow height. Beaver have remained at carrying capacity over the last 20 years, and average willow canopy cover increased from 16% in 1981 to 37% in 2019. The probability of willow occurrence increased the longer beaver occupied an area and with colony density (colonies/km). Moose relative abundance declined from 1987 to 2021, while average willow height increased from 113cm in 1988 to 190cm in 2021 and browsing decreased from 53% in 1989 to 3% in 2021. Browsing was an important factor limiting willow height. Moose abundance had a positive linear relationship with average browsing pressure and negative linear relationship with average willow height. This study shows that the southern ABW was able to recover from historic over-browsing and beaver extirpation. The long-term effects of beaver reintroduction and reduced moose numbers in a historically degraded environment enhanced willow, indicating that under the right circumstances, willow communities have the potential to recover from a previously degraded state.Item Reproduction of moose in southwestern Montana(Montana State University - Bozeman, College of Letters & Science, 1961) Peek, James M.Item Food habits, movements and population structure of moose in the Gravelly Mountains, Montana(Montana State University - Bozeman, College of Letters & Science, 1959) Knowlton, Frederick FrankItem Relations of moose, cattle, and willows in southwestern Montana(Montana State University - Bozeman, College of Letters & Science, 1969) Dorn, Robert D.Item Winter ecology of moose on the Northern Yellowstone Winter Range(Montana State University - Bozeman, College of Letters & Science, 2003) Tyers, Daniel BruceItem Seasonal distribution, winter habitat selection and willow utilization patterns of the Shiras moose on the Mount Haggin Wildlife Management Area(Montana State University - Bozeman, College of Letters & Science, 2012) Burkholder, Braden Osborn; Chairperson, Graduate Committee: Robert A. GarrottMoose populations are difficult to manage as moose exist at low population densities compared to other ungulates and may use a variety of habitat types. Local knowledge is needed to effectively manage moose populations and limited research has been conducted recently in Montana. This study took place on the Mount Haggin Wildlife Management Area (MHWMA) in southwestern Montana to assist with the management of moose throughout southwestern Montana and establish a baseline for future research. The objectives of this study were to describe seasonal distribution patterns and habitat selection by adult cow moose, with an emphasis on habitat selection during the winter season, and to quantify patterns in willow browse utilization by moose in winter. To accomplish these objectives, I used data from GPS collars on cow moose to determine the basic habitat use patterns and covariates associated with winter habitat selection. Browse surveys of willow were employed to quantify browse utilization on the study area and to determine which environmental covariates were associated with moose browse utilization in winter. Cow moose on the study area were non-migratory and had small winter and summer home ranges. Moose strongly selected for willow cover types and habitat selection was associated with cover type, distance to conifer, distance to willow, and elevation; these relationships changed when snowpack conditions varied. Current browse utilization was low (~10%) and was associated with previously browsed willow, preferred willow species, and willow community width. Based on the habitat selection analysis, both willow and conifer communities were important to cow moose in winter and these results have management implications for habitat conservation and aerial survey methods. The browse utilization analysis showed that browse was notably heterogeneous and would require a large effort to sample browse utilization accurately. However, browse patterns were associated with habitat covariates and habitat managers should take these covariates into account when placing sites for monitoring of willow browse utilization. Overall, the moose population and willow communities around MHWMA appear to be in good health, but threats from climate change, predation, and the potential for overharvest may create population management challenges in the future.Item Home range characteristics of sympatric moose and white-tailed deer in northern Minnesota(Montana State University - Bozeman, College of Letters & Science, 2004) Cobb, McCrea Andrew; Chairperson, Graduate Committee: Lynn Irby; Rick Lawrence; (co-chair)Moose (Alces alces) and white-tailed deer (Odocoileus virginianus) population numbers in northern Minnesota have fluctuated recently, possibly due to habitat changes, interspecific competition, and meningeal worm (Parelaphostrongylus tenuis). Little is known currently about the relative distribution and home range characteristics of sympatric moose and white-tailed deer in this area. Surveys were conducted during the winters of 1989 and 1991 to determine the relative distributions of moose and whitetailed deer pellet groups in Voyageurs National Park (VNP). Moose and white-tailed deer home ranges were determined using an adaptive kernel technique and applied to aerial radio telemetry relocations from 1989 to 1991. I examined the habitat selections of moose and white-tailed deer through compositional analysis at the home-range and corearea scales. Pellet transect data revealed a low abundance of moose and a high abundance of white-tailed deer and provided evidence of some spatial separation between moose and deer ranges in VNP. This evidence was supported by little interspecific home range overlap between radio collared moose and white-tailed deer. Moose home ranges in VNP were larger than any previously reported in the contiguous United States, and white-tailed deer home ranges were larger than any previously reported for the region. There was no apparent difference in home range sizes between the sexes for moose and white-tailed deer, although small sample sizes precluded precise statistical testing. Compositional analysis did not detect any habitat preference at the core-area scale for either moose or white-tailed deer. Both moose and white-tailed deer exhibited a significant preference for spruce/balsam fir habitats at the home-range scale. Canopy density and height preferences differed between moose and white-tailed deer at the homerange scale. Differential habitat preferences between moose and white-tailed deer in VNP might be related to the differences between these species' abilities to cope with northern mid-continent climates. The apparent spatial separation and different habitat preferences between moose and white-tailed deer might provide a refuge for moose from meningeal worm-infected white-tailed deer in VNP and could be a factor in the coexistence of the species.