Theses and Dissertations at Montana State University (MSU)
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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 Dormant season grazing of northern mixed grass prairies: effect of supplementation and winter environmental conditions on beef cattle grazing behavior, residual vegetation conditions and variation in supplement intake(Montana State University - Bozeman, College of Agriculture, 2019) Wyffels, Samuel Aaron; Chairperson, Graduate Committee: Lance McNew; Janice G. P. Bowman (co-chair); Lance B. McNew, Janice G.P. Bowman, Mark K. Petersen, Darrin L. Boss and Bok F. Sowell were co-authors of the article, 'Dormant season grazing of northern mixed grass prairies: the effect of supplementation strategies on heifer resource utilization and vegetation use' submitted to the journal 'Rangeland ecology & management' which is contained within this thesis.; Lance B. McNew, Janice G.P. Bowman, Mark K. Petersen, Darrin L. Boss and Bok F. Sowel were co-authors of the article, 'Dormant season grazing on northern mixed grass prairie agroecosystems: does protein supplementation and individual animal variation impact beef cattle resource use, vegetation and residual cover for wildlife' submitted to the journal 'Rangeland ecology & management' which is contained within this thesis.; Lance B. McNew, Janice G.P. Bowman, Mark K. Petersen, Darrin L. Boss and Bok F. Sowell were co-authors of the article, 'The influence of age and environmental conditions on supplement intake by beef cattle winter grazing a northern mixed-grass rangeland in Montana' submitted to the journal 'Rangeland ecology & management' which is contained within this thesis.Dormant season grazing reduces reliance on harvested feeds, but typically requires protein supplementation to maintain animal performance and vegetation utilization across the landscape. However, information relating supplementation strategies and supplement intake behavior to individual grazing behavior and resource utilization on dormant forage is lacking. Thus, the intent of this research is to examine cattle resource utilization, supplement intake behavior, residual cover of vegetation and utilization on rangelands grazed during the dormant season. One hundred weaned heifer calves were randomly selected and placed into one of two supplementation treatments in each of 2 years (50 heifers/treatment/year); one receiving a free access 62% crude protein self-fed mineral/protein concentrate, and the other receiving a daily hand-fed 20% crude protein cake while grazing December through March. Additionally, a commercial herd of 300 bred cows ranging in age from 1- to 12-yr-old were provided a 30% crude protein self-fed supplement with 25% salt to limit intake in a SmartFeed Pro self-feeder system to measure individual animal supplement intake from November to January in each of 2 years. In both grazing trials, transects were randomly located within each pasture for measuring vegetation composition, production and quality, canopy cover and visual obstruction readings pre and post grazing. Grazing locations were monitored for individuals with Global Positioning System collars containing head position sensors that record daily space use and location of grazing activities. Data sets were used to quantify space use with generalized linear models to assess cattle resource utilization and supplementation behavior. Cattle provided the hand-fed cake selected grazing location near supplement delivery sites and spent less time grazing per day than self-fed supplemented cattle. Substantial amounts of herd-level variability in both studies suggests individual attributes are major drivers in cattle resource use. Supplement treatment and grazing intensity had little impact on residual vegetation conditions, however, the timing of grazing and year did affect the response of residual vegetation to grazing. Younger cattle consumed more supplement with less variability than older aged cattle. This research provides multidimensional insight to stakeholders concerning grazing behavior and the ecological impacts of late season use on Montana rangelands.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 The effects of fire and grazing in the northern mixed-grass prairie : implications from the Pautre wildfire(Montana State University - Bozeman, College of Agriculture, 2016) Gates, Emily Ann; Chairperson, Graduate Committee: Clayton B. Marlow; Lance T. Vermeire, Clayton B. Marlow and Richard C. Waterman were co-authors of the article, 'Reconsidering rest following fire: northern mixed-grass prairie is resilient to spring wildfire and resistant to moderate post-fire grazing' submitted to the journal 'Rangeland ecology and management' which is contained within this thesis.; Lance T. Vermeire, Clayton B. Marlow and Richard C. Waterman were co-authors of the article, 'Season of post-fire defoliation: effects on biomass, community composition and ground cover' submitted to the journal 'Rangeland ecology and management' which is contained within this thesis.; Lance T. Vermeire, Clayton B. Marlow and Richard C. Waterman were co-authors of the article, 'Forage fiber digestibility dynamics in the northern mixed-grass prairie following spring wildfire' submitted to the journal 'Rangeland ecology and management' which is contained within this thesis.Current federal recommendations pertaining to the management of post-fire grazing on rangelands interrupts historic disturbance regimes of the North American prairies by indicating that fire and grazing should be separated by at least two growing seasons. In contrast, some scholars suggest that North American prairie evolved under a tight linkage of fire and proximate post-fire grazing and should be well adapted to these combined disturbances. The Pautre wildfire of April 2013 provided an opportunity to test the effects of post-fire grazing in the northern mixed-grass prairie. One grazing allotment, burned in its entirety, and three burned and nonburned sites spanning a north-south gradient of the fire perimeter were selected as study locations. The effects of grazing versus rest, defoliation during the first spring, summer, or fall following the fire on burned and nonburned sites and the effects of fire on forage fiber digestibility were tested. Sites grazed during the first two growing seasons following the fire were found to recover similarly to sites rested during that same time. In addition, defoliation during any season following the fire produced no negative effects when compared to nondefoliation. Increases in forage fiber digestibility peaked shortly after fire and were short-lived, diminishing by the following year. These results lend support to the theory that fire and grazing were historically linked disturbances throughout the evolution of the North American prairies, indicating that the federal recommendation of rest is unnecessary in at least the northern mixed-grass prairie ecoregion. Historic, evolutionary patterns of disturbances, such as fire and grazing, may be useful in determining the most appropriate post-fire management regimes for specific ecoregions.Item Effects of prescribed burning on mixed prairie vegetation in southeastern Montana(Montana State University - Bozeman, College of Agriculture, 1981) Rennick, R. B.Item Effects of black-tailed prairie dogs on the mixed-grass prairie in Montana(Montana State University - Bozeman, College of Agriculture, 2002) Johnson, Carolyn Marie