Theses and Dissertations at Montana State University (MSU)
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Item Movement ecology of female sage-grouse informs space use, resource selection, and demography in southern Valley County, MT(Montana State University - Bozeman, College of Agriculture, 2023) Haynam, Robert Thomas, III; Chairperson, Graduate Committee: Lance McNew; This is a manuscript style paper that includes co-authored chapters.The greater sage-grouse (Centrocercus urophasianus) is a focal species in the effort to conserve imperiled sagebrush ecosystems and associated organisms. Sage-grouse uses of landscapes are modulated by their multilevel movement processes. Understanding the relative contributions of hard-wired and environmental influences on movement processes is necessary for a comprehensive understanding of sage-grouse ecology. Correlates between fitness components and measurable landscape conditions may be of limited value if other influences such as sage-grouse movement and behavior are not accounted for. Movement behaviors may be risky in certain contexts and adaptive in other contexts, and differences in the characteristics of movement and therefore space-use among individuals can have implications for survival and reproductive performance. We collected detailed records of sage-grouse movements for up to 4 years per individual to investigate daily behavioral strategies of sage-grouse and therefore mechanisms driving habitat use and individual performance. During April-May, 2018-2019, we captured 86 (45 in 2018, 41 in 2019) female sage-grouse and outfitted them with GPS transmitters. We collected 192,640 geographic coordinates of 86 female sage-grouse during 2018-04-24 - 2022-04-14 which encompassed 4 complete annual cycles of sage-grouse. We confirmed 185 nest attempts of 76 individuals during the nesting seasons of 2018-2021. Hard-wired or learned seasonal behavior modes appeared to be more influential than vegetation conditions. Sage-grouse can exhibit reactive responses to landscape conditions but also use the landscape as a function of high-level endogenous constraints likely due to memory mechanisms, high temporal predictability of some resources, and moderate spatial heterogeneity of resources. Management prescriptions may ignore important ecological levels such as those responsible for learned-heuristic movement and space use modes. Relationship and magnitude of associations among sage-grouse use-intensity and landscape conditions varied among 7 behavior modes which indicates that behavioral and temporal context is important for understanding habitat and space use by sage-grouse. Our findings also support a fundamental demographic importance of area affinity, fidelity, and familiarity to sage-grouse ecology which has been overlooked in most research on sage-grouse or other birds.Item Greater sage-grouse (Centrocercus urophasianus) nest survival and nest predator response to fence modifications in a grazing modified landscape(Montana State University - Bozeman, College of Agriculture, 2023) O'Harra, Aaron William; Chairperson, Graduate Committee: Bok Sowell; This is a manuscript style paper that includes co-authored chapters.Livestock operations are present across much of the greater sage-grouse (Centrocercus urophasianus; sage-grouse) current range and the infrastructure associated with this land-use type can have negative effects on sage-grouse populations. Recent work has found that the daily survival rate of nests placed close to fences experience a 4-fold decrease in survival probability. The reduction in survival was theorized to be attributed to higher use of fences by predators due to increased movement efficiency and foraging rates predators experience along linear features. In this study, we experimentally modified fences to reduce perch availability and the barrier effects often associated with fences to improve sage-grouse nest survival. We monitored 177 nests over 8 years to assess the effectiveness of this management technique. We also used camera traps and point count surveys in the last 3 years of the study to assess the occurrence of three common sage-grouse nest predators; badgers (Taxidea taxus), coyotes (Canis latrans), and avian predators. We modeled daily nest survival against modified and traditional fences and landscape features throughout our study area in a Bayesian framework. Our predator occurrence rates were modeled using a single season occupancy model in relation to similar landscape features used for nest survival modeling. We detected evidence of an increase in nest survival of 11.4% (90% CRI: 3.2%, 20.0%) for sage grouse nests placed closer to modified fences (mean survival = 35.8%) when compared to traditional fence types (mean survival = 24.4%). We also found evidence for a 14% (95% CI: 5%, 23%) decrease in badger occurrence and a 15% (95% CI: 12%, 18%) increase in coyote occurrence along recently modified fences. We found no evidence that avian predators used fences more than areas with no fence present. Our results may be influenced by the distribution of fence types between sagebrush species. Our results indicate that predation risk for sage-grouse nests across a landscape is predator specific. We conclude that modifying fences in this way can improve sage-grouse nest survival, and the effectiveness of these modifications is controlled by a combination of the predators and landscape features associated with a nest site.Item Carry-over effects in partially migratory greater sage-grouse, southwest Montana(Montana State University - Bozeman, College of Letters & Science, 2022) Waxe, James Andrew; Chairperson, Graduate Committee: Andrea Litt; This is a manuscript style paper that includes co-authored chapters.Migration is a common natural phenomenon and an important life history strategy for many animal species. Migration allows individuals to accommodate changing environmental conditions, with the potential to increase survival or future reproduction. Many migratory species are subject to carry-over effects, where conditions experienced during one season or life stage influence subsequent life stages. Previous research has largely focused on evaluating the influence of carry-over effects on long-distance migrants, but less is known about these influences on shorter-distance migrants. During research in southwest Montana and southeast Idaho, we used VHF radio collars, red blood cells, stable isotopes, and morphometric information to understand the influence of carry-over effects on Greater Sage-grouse. In this population, some individuals migrate only short distances, while others may not migrate at all. We evaluated the influence of 1) different migration strategies and breeding locations on the body condition of females before breeding and 2) how variation in pre-breeding body condition influenced subsequent reproduction. We found non-migratory individuals were in better pre- breeding body condition than migrants during years with less winter precipitation. Similarly, individuals who experienced less precipitation during the breeding season also had higher pre- breeding body condition. Pre-breeding body condition positively influenced offspring weight early in the breeding season, but this relationship was less apparent later in the season. Our data suggest carry-over effects occur in this population of sage-grouse, but the magnitude of these effects was largely dependent on environmental conditions and timing of breeding. With increasing evidence of carry-over effects in sage-grouse populations, managers should broaden their conservation strategies to account for all life stages. Protecting a variety of winter habitat both near and distant from breeding areas will ensure the persistence and reproductive contribution of individuals with different migration strategies. Furthermore, protecting all known sage-grouse leks provides variation within a single population which allows for flexibility to respond in changing environments. Maintaining or enhancing landscape-level habitat heterogeneity supports variable life-history strategies and is critical for sage-grouse conservation.Item Breeding ecology of greater sage-grouse in southwestern Montana(Montana State University - Bozeman, College of Agriculture, 2021) Cutting, Kyle Anthony; Chairperson, Graduate Committee: Jay J. Rotella and Bok Sowell (co-chair); Jay J. Rotella, Sean R. Schroff, Michael R. Frisina, James A. Waxe, Erika Nunlist and Bok F. Sowell were co-authors of the article, 'Maladaptive nest-site selection by a sagebrush dependent species in a grazing-modified landscape' in the journal 'Journal of environmental management' which is contained within this dissertation.; Jay J. Rotella, Emma Grusing, James A. Waxe, Erika Nunlist and Bok F. Sowell were co-authors of the article, 'Nutrient sources for offspring formation: diet-mother and mother-offspring isotopic discrimination in domesticated gallinaceous birds' submitted to the journal 'Isotopes in environmental and health studies' which is contained within this dissertation.; Jay J. Rotella, James A. Waxe, Aaron O' Harra, Sean R. Schroff, Lorelle Berkeley, Mark Szczypinski, Andrea R. Litt, Bok F. Sowell were co-authors of the article, 'Resource allocation effects on the timing of reproduction in an avian habitat specialist' in the journal 'Ecosphere' which is contained within this dissertation.The greater sage-grouse (Centrocercus urophasianus; hereafter: sage-grouse) is an umbrella species that needs large intact tracts of sagebrush habitat with habitat requirements that represent the needs of many other species found in the sagebrush biome of the American West. Much of the information collected to date on sage-grouse is from low-elevation, homogenous, landscapes, leaving information gaps for topographically complex, high elevation locations within the sage-grouse range. In this dissertation, I assess the following aspects of the breeding ecology of sage-grouse: 1) how females select nest and brood sites based on sagebrush type, along with livestock grazing features and other biotic and abiotic characteristics; 2) the influence of female nest-site selection on nest-survival outcomes; 3) experimentally derived isotopic discrimination values in domesticated gallinaceous birds as an estimation method for nutrient allocation strategies in wild sage-grouse; and 4) the degree to which females allocated nutrients from winter habitats for formation of offspring by comparing females nesting in southwest vs. central Montana. Based on the research, I found evidence that: 1) sage-grouse avoid a high-elevation sagebrush type that is the most common type in my study region and instead select for intermediate- or low-elevation sagebrush types for both nesting and brood rearing, 2) sage-grouse broods selected sites away from low-lying mesic areas and near ridgelines on upper slopes with south-facing aspects and sites further from cattle paths, 3) nest survival was (a) higher for nests placed away from fence lines, (b) lower in areas with more cow pies and taller dead grass, and (c) higher in areas with increased living grass cover, and 4) females from southwest Montana and in the high-elevation sagebrush type primarily allocated nutrients from winter habitats, whereas females from central Montana and in the low-elevation sagebrush type primarily allocated nutrient sources from spring habitats for offspring formation. My findings highlight a unique breeding strategy for sage-grouse residing in high-elevation sagebrush landscapes. Results described herein will allow managers in southwest Montana, and other regions in the northern Rocky Mountains, to better manage sage-grouse and sage-grouse habitats.Item Can targeted cattle grazing increase abundance of forbs or arthropods in sage-grouse brood-rearing habitat?(Montana State University - Bozeman, College of Agriculture, 2018) Payne, Jarrett MacKenzie; Chairperson, Graduate Committee: Jeffrey C. MosleySuboptimal brood-rearing habitat often limits greater sage-grouse (Centrocercus urophasianus) populations in western North America. In mountain big sagebrush (Artemisia tridentata Nutt. ssp. vaseyana [Rydb.] Beetle) brood-rearing habitat, dense sagebrush canopy cover (> 25% cover) may limit the understory forbs and arthropods that sage-grouse prefer to eat during summer. Targeted cattle grazing is a potential habitat management tool to reduce dense sagebrush. This study evaluated targeted cattle grazing on a landscape scale to increase forbs and arthropods within core sage-grouse brood-rearing habitat. Objectives of this study were to evaluate how well targeted cattle grazing reduced mountain big sagebrush canopy cover, increased forb abundance and diversity, and increased arthropod abundance. Targeted cattle grazing was applied within two large, contiguous pastures (625 ha each) in the Beaverhead Mountains of southwestern Montana. The two pastures were grazed simultaneously at a light stocking rate (6.25 ha/AUM) for two weeks each year in mid-October 2015 and 2016. Vegetation and arthropod responses were measured during the following June-early July (2016 and 2017, respectively) within 32 microsites where mountain big sagebrush canopy cover exceeded 30% pre-treatment. Microsites were 0.008 ha to match the spatial scale at which sage-grouse broods select fine-scale habitat. One of two treatments was randomly assigned to each microsite: a low moisture block protein supplement or no supplement (unsupplemented). In the first summer after treatment, supplemented microsites averaged 78% less sagebrush canopy cover (8% vs. 36%; P < 0.001) and 25% more forb canopy cover (15% vs 12%; P = 0.122). Sage-grouse forb canopy cover was 50% greater in supplemented microsites (3% vs. 2%; P = 0.003). Forbs also comprised a greater proportion of the herbaceous understory in the supplemented vs. unsupplemented sites (48% vs. 36%; P = 0.002). Arthropod abundances were greater in supplemented than unsupplemented microsites only during the wet year of 2017 when arthropods were 1.7-1.8x more abundant in supplemented microsites. Sagebrush canopy cover was reduced by cattle trampling, not browsing. My results demonstrate that targeted cattle grazing can increase abundance of forbs and arthropods in mesic, dense stands of mountain big sagebrush in sage-grouse brood-rearing habitat.Item Nest site selection and brood home ranges of greater sage-grouse (Centrocercus urophasianus) in the Centennial Valley, Montana(Montana State University - Bozeman, College of Agriculture, 2016) Schroff, Sean Rudolf; Chairperson, Graduate Committee: Bok Sowell; Kyle A. Cutting, Craig A. Carr, Michael R. Frisina, Lance B. McNew and Bok F. Sowell were co-authors of the article, 'Fine-scale nest site selection of greater sage-grouse (Centrocercus urophasianus) in the Centennial Valley, Montana' submitted to the journal 'The condor' which is contained within this thesis.; Kyle A. Cutting, Craig A. Carr, Michael R. Frisina and Bok F. Sowell were co-authors of the article, 'Brood home range sizes of greater sage-grouse in response to cattle grazing in the Centennial Valley, Montana' submitted to the journal 'The condor' which is contained within this thesis.The purpose of this study was to estimate the fine-scale nest site selection of greater sage-grouse (Centrocercus urophasianus) and to investigate the differences in brood home range size in response to cattle grazing in the Centennial Valley, Montana. A total of 111 sage-grouse hens were captured across two breeding seasons (2014-2015). Hens were captured on leks using spotlighting/dip netting techniques. A total of 90 nests were found across both breeding seasons using radio-collared sage-grouse (VHF). Vegetation surveys were conducted at nests and random sites that measured the nest shrub and the cover within 3 m of the nest. All habitat variables that were included in the top model (GLMs) were nest shrub morphological characteristics and the cover provided by the nest shrub. It appears that sage-grouse are selecting nest sites based on the concealment provided by the nest shrub. Forty-five percent of nests were under mountain big sagebrush plants (Artemisia tridentata ssp. vaseyana), 21% nests were under three-tip sagebrush (A. tripartita), and 20% of nests were under basin big sagebrush plants (A. tridentata ssp. tridentata). Nests under mountain big sagebrush and three-tip sagebrush shrubs provided twice the amount of lateral cover that basin big sagebrush provided. Of the 90 nests found, 18 produced successful broods. Grazing utilization levels, grass heights, and dominant sagebrush type were recorded at brood locations and extrapolated to estimate those values across the brood's home range. Two sample t-tests were used to test if there was a difference between the habitat variables in grazed and ungrazed pastures as well as by habitat type. Grazing utilization levels were on average 4% in brood home ranges across both years of the study. There was no year effect in brood home range size and brood home range size did not differ by grazed and ungrazed pastures or across the two habitat types the broods used. Brood home range size is most likely delineated by other factor(s) besides cattle grazing. Managers should focus on conserving continuous stands of mountain big sagebrush and three-tip sagebrush habitats because they provide higher concealment for nesting and were highly used for brood-rearing.Item The food habits and summer distribution of juvenile sage grouse in central Montana(Montana State University - Bozeman, College of Letters & Science, 1969) Peterson, Joel GordonItem An appraisal of endocrine activity in strutting sage grouse(Montana State University - Bozeman, College of Agriculture, 1969) Thorvilson, Roger CecilItem Sage grouse, lagomorph, and pronghorn use of a sagebrush grassland burn site on the Idaho National Engineering Laboratory(Montana State University - Bozeman, College of Letters & Science, 1983) Gates, Robert JohnItem Summer movements and habitat use by sage grouse broods in central Montana(Montana State University - Bozeman, College of Letters & Science, 1970) Wallestad, Richard Orville