Theses and Dissertations at Montana State University (MSU)
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Item Evaluating habitat suitability for lesser prairie-chicken conservation in the mixed-grass prairie ecoregion(Montana State University - Bozeman, College of Agriculture, 2022) Solomon, Morgan Jean; Chairperson, Graduate Committee: Lance McNewPopulations of lesser prairie-chickens (Tympanuchus pallidicinctus; hereafter "prairie-chicken") in the southern Great Plains have declined by an estimated 85% and the species is currently being reconsidered for protections under the federal Endangered Species Act. Despite efforts to increase the quantity, quality, and connectivity of available habitat, prairie-chicken populations in the mixed-grass prairie ecoregion have remained relatively stable-to-declining. To provide information that will assist in providing more appropriate qualifications of available prairie-chicken habitat, I used ensemble modeling approaches and a least-cost path analysis to develop spatially-explicit predictions of prairie-chicken habitat and assess connectivity of identified habitat within the mixed-grass prairie ecoregion. In addition, I provided a critical comparison of the Western Association of Fish & Wildlife Agencies (WAFWA) Habitat Evaluation Guide and research-based field indices used to quantify the amount and quality of habitat for prairie-chicken conservation on a proprety participating in an incentive-based conservation program. I also explored the potential for using ecological site descriptions and relative condition (similarity index) to monitor reproductive habitat for prairie-chickens. Predictions from our ensembled model identified ~4,576 km 2 of potentially suitable prairie-chicken habitat both occupied and unoccupied. Least-cost path analyses revealed a low degree of connectivity between areas of occupied and unoccupied habitat indicating a low probability of natural recolonization. Managers should consider focusing conservation efforts on targeting habitat restoration between, within and around areas of identified occupied and unoccupied habitat. Habitat quality under the HEG habitat assessment protocol showed the property had excellent prairie-chicken habitat quality while research-based estimates showed the property only had marginal habitat quality for prairie-chickens. Differences in habitat quality assessments were in areas that had low percent cover of vegetation species preferred by prairie-chickens and in areas that had recently experienced fire. Thus, managers should consider using components of both habitat assessments protocols when quantifying habitat for prairie-chicken conservation to reduce the probability of producing erroneous estimates of habitat quality. Limited sample size within moderate categories of similarity index across ecological sites prevented us from reliably executing further analyses exploring the utility of using a similarity index as a tool for monitoring prairie-chicken habitat.Item Effects of grazing management on sharp-tailed grouse ecology in mixed-grass prairies(Montana State University - Bozeman, College of Agriculture, 2019) Milligan, Megan Cochran; Chairperson, Graduate Committee: Lance McNew; Lorelle I. Berkeley and Lance B. McNew were co-authors of the article, 'Effects of rangeland management on the nesting ecology of sharp-tailed grouse' in the journal 'Rangeland ecology and management' which is contained within this thesis.; Lorelle I. Berkeley and Lance B. McNew were co-authors of the article, 'Effects of rangeland management on the survival of adult sharp-tailed grouse' submitted to the journal 'Journal of wildlife management' which is contained within this thesis.; Lorelle I. Berkeley and Lance B. McNew were co-authors of the article, 'Effects of rangeland management on the habitat selection of sharp-tailed grouse in the mixed-grass prairie' submitted to the journal 'PLOS one' which is contained within this thesis.Many grassland species co-evolved with large herbivores and require habitats along the entire structural gradient created by grazing. Widespread declines of grassland birds, however, have prompted concerns about rangeland management. Conceptually, rest-rotation grazing functions as a conservation strategy to mimic historic disturbance regimes and create pasture-level heterogeneity in the absence of fire, but its utility for improving grouse habitat has not been tested. We evaluated rest-rotation grazing as a conservation management technique compared to traditional grazing systems, including summer rotation and season-long grazing, and assessed the effects on sharp-tailed grouse (Tympanuchus phasianellus), an indicator species for grassland ecosystems. We monitored radio-marked female sharp-tailed grouse in eastern Montana and western North Dakota during 2016-2018 to monitor nesting ecology, adult survival, and habitat selection. Both nest site selection and nest survival were directly related to vertical nesting cover, which was only weakly related to grazing management variables, including grazing system and stocking rate, at moderate stocking rates (< or = 2 AUM ha^-1). Cattle presence during the nesting period had a positive effect on daily nest survival, potentially because either the cow or rancher presence affected predator behavior. Grazing management did not have a meaningful influence on any aspect of the overall survival of adult female sharp-tailed grouse, although seasonal patterns of mortality risk differed among systems. More importantly, cropland increased mortality risk of adult female sharp-tailed grouse. At broad spatial scales, females selected for grassland habitats, but exhibited limited to no selection for either landscape or management variables when selecting habitat at smaller spatial scales. We found limited evidence that grazing management was a driver of habitat selection at either spatial scale examined. Furthermore, female sharp-tailed grouse exhibited strong individual variation in both home range size and third-order habitat selection. Taken together, our results suggest that rest-rotation grazing did not influence any aspect of sharp-tailed grouse ecology we studied relative to other grazing systems and did not increase pasture-level heterogeneity in relevant vegetation variables. Therefore, grazing management strategies with moderate stocking rates that preserve large intact grasslands are a better conservation strategy for sharp-tailed grouse than prescribing specific grazing systems.Item Associations of broad scale vegetation characteristics and abundances, nest densities, and nest survival of mixed-grass prairie songbirds in northern Montana(Montana State University - Bozeman, College of Agriculture, 2019) Pulliam, John Patrick; Chairperson, Graduate Committee: Lance McNewGrassland bird populations are declining faster than any other avian guild. In northern Montana, four species are experiencing severe population declines: Baird's sparrow (Centronyx bairdii), chestnut-collared longspur (Calcarius ornatus), McCown's longspur (Rynchophanes mccownii), and Sprague's pipit (Anthus spragueii). In 2017 and 2018, I evaluated abundance, nest density and nest survival of these species in relation to local vegetative conditions with the goal of identifying important breeding season vegetation conditions to inform management. I conducted fixed-radius point-counts at 100 sites to estimate local abundance, rope drag surveys to estimate nest density, nest monitoring to estimate nest survival, and vegetation surveys to estimate vegetation structure and composition across grassland habitats in Phillips County, MT. Point-counts and rope drag surveys were carried out with replicated visits to allow estimation of species-specific detection probabilities. Vegetation conditions were measured at the plot level (9-ha) to provide information at scales relevant for land managers. The abundance of Baird's sparrows was positively associated with residual grass cover and litter cover. Chestnut-collared longspur abundance was negatively associated with residual grass, exotic grass, and shrub cover and had a quadratic relationship with biomass. Plot-level abundance of McCown's longspurs was negatively associated with both shrub cover and biomass. Sprague's pipit abundance declined with exotic grass cover and exhibited a quadratic relationship with biomass. Limited sample size only allowed inference of nest density and nest survival for chestnut-collared longspurs. Nest density was negatively associated with plot scale exotic grass cover, biomass, and slope. I did not find support for any vegetation covariates on nest survival for chestnut-collared longspurs. These results provide some guidance for landscape managers interested in improving habitat for these species. The contrasting results among species, however, emphasize the need for heterogeneity in vegetation structure and composition. The disconnect between relevant covariates for nest density and nest survival suggest possible maladaptation for chestnut-collared longspurs. This result suggests that an index of productivity for this species that does not include both nest density and nest survival may produce erroneous results.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.Item Habitat use and distribution of bison in Theodore Roosevelt National Park(Montana State University - Bozeman, College of Agriculture, 1984) Norland, Jack EugeneItem Site characteristics and effect on elk and mule deer use of the Gardiner winter range, Montana(Montana State University - Bozeman, College of Agriculture, 1984) McNeal, Allen FrancisItem Influence of social rank on habitat use and performance of free-ranging cattle(Montana State University - Bozeman, College of Agriculture, 2000) Macdonald, B. Ross; Chairperson, Graduate Committee: Jeffrey C. Mosley.Item Fall cattle grazing to improve deer and elk forage on a rough fescue range(Montana State University - Bozeman, College of Agriculture, 2000) Short, Jeffery JonItem Influences of browsing and fire on sagebrush taxa of the Northern Yellowstone Winter Range(Montana State University - Bozeman, College of Agriculture, 1995) Mehus, Chris AllenItem The influence of Douglas-fir and Rocky Mountain juniper on Wyoming and mountain big sagebrush cover in Southwest Montana(Montana State University - Bozeman, College of Agriculture, 2010) Kitchen, Karen Ann; Chairperson, Graduate Committee: Bok Sowell.Expansion of conifers into sagebrush steppe is a management concern, since conifers reduce sagebrush cover for wildlife. The primary objective of this research was to examine the relationship between the conifers, Douglas-fir (Pseudotsuga menziesii) and Rocky Mountain juniper (Juniperus scopulorum), and two subspecies of big sagebrush, Wyoming big sagebrush (Artemisia tridentata spp. wyomingensis) and mountain big sagebrush (Artemisia tridentata spp. vaseyana), in southwest Montana using a best-fit model. A secondary objective was to determine whether either of the two conifer species have a greater influence on sagebrush cover. Percent cover of both conifers and sagebrush was recorded at 40 Wyoming and 40 mountain big sagebrush plots at each of three study sites in southwest Montana (n = 240). The best-fit model utilizes the terms site, sagebrush subspecies, the square root of conifer cover, and site by sagebrush subspecies as the independent variables, with the square root of sagebrush cover as the dependent variable. The model (the square root of sagebrush cover = a i - 0.401 x the square root of conifer cover; r ² = 0.61) found a negative relationship between conifer cover and sagebrush cover and indicates that there is no difference between the two sagebrush subspecies and across all three sites in the study area. The best-fit model was validated within the 95 % confidence interval at all three study sites. Validation trials with data from three sites outside the study area were successful for one site, suggesting that the model is better suited to lower elevation, less productive sites. There was no difference in the influence of Douglas-fir or Rocky Mountain juniper cover on live sagebrush cover, indicating that sagebrush responds similarly to competition from both species. Controlling both conifers may increase sagebrush cover slightly, but responses will be small due to low levels of initial sagebrush cover. If maintenance of sagebrush cover is desired, conifer control should be initiated before conifer cover reaches 10 %, since the rate of sagebrush decline is highest at low levels of conifer cover. However, conifer control is not recommended because both conifers and sagebrush are important components of big game winter range.