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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 Paleoecological utility of feeding traces at Egg Mountain, a rich terrestrial vertebrate locality of the upper Cretaceous Two Medicine Formation, Montana, U.S.A.(Montana State University - Bozeman, College of Letters & Science, 2020) Freimuth, William James; Chairperson, Graduate Committee: David Varricchio; David J. Varricchio, Alexandria L. Brannick, Lucas N. Weaver and Gregory P. Wilson were co-authors of the article, 'Mammal-bearing regurgitalites potentially attributable to Troodon formosus at the Egg Mountain locality, upper Cretaceous Two Medicine Formation, Montana, U.S.A.' submitted to the journal 'PLOS ONE' which is contained within this thesis.; David J. Varricchio, Karen Chin and Sara E. Oser were co-authors of the article, 'Paleoecological implications of invertebrate fecal pellets (Edaphichnium) at a rich terrestrial vertebrate locality, upper Cretaceous Two Medicine Formation, Montana, USA.' submitted to the journal 'Journal of paleontology' which is contained within this thesis.The Egg Mountain locality is a rich terrestrial vertebrate site from the Upper Cretaceous Two Medicine Formation of Montana. Numerous skeletal remains and nesting and dwelling traces of insects and other invertebrates, mammals, lizards, and carnivorous and herbivorous dinosaurs are known from the locality. Despite the diversity of different taxa and behaviors represented, little is known about their respective ecologies. To address this, I investigate a series of feeding traces, including regurgitalites (fossil gastric pellets) and invertebrate fecal pellets, and assess their potential trace-makers and paleoecological and paleoenvironmental implications for the site. Two amalgams of the metatherian Alphadon halleyi are identified as regurgitalites based on the presence of multiple individuals in a confined area, an abundance of paired and indigestible tooth-bearing cranial elements, extensive breakage and disarticulation, and periosteal corrosion patterns attributable to digestion. These are the first mammal-bearing regurgitalites from the Mesozoic. A third amalgam is composed of the multituberculate Filikomys primaevus and is represented by crushed skulls and abundant articulated postcrania, suggestive of a non-predatory origin. The available evidence favors Troodon formosus as the regurgitalite producer. The similar taphonomic features of these regurgitalites and the prey in regurgitates of diurnal raptors suggest Troodon may have manipulated prey during feeding. The ability to egest pellets in a large-bodied, non-volant troodontid supports previous hypotheses that avian-style pellet egestion may have evolved to accommodate increased physiological processes leading to modern birds. A series of unusual peloidal structures are interpreted as invertebrate fecal pellets and resemble the pellet-filled burrow trace Edaphichnium isp. Three morphotypes are identified, including linearly-arranged pellets, pellets in condensed masses, and pellets in dispersed masses. Potential trace-makers include coleopterans, millipedes, and possibly earthworms. The abundance of Edaphichnium isp. and other traces at specific horizons throughout the locality suggest buildup of organic material in the substrate, likely induced by depositional hiatuses. Some Edaphichnium isp. are associated with Maiasaura egg clutches, suggesting invertebrate communities scavenged the decaying nest materials. Taken together, these studies provide ecological and depositional context to the abundance of dinosaur nesting and the diversity of taxa and behaviors represented at the Egg Mountain locality.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 Plant-pollinator network assembly after wildfire(Montana State University - Bozeman, College of Letters & Science, 2018) Simanonok, Michael Peter; Chairperson, Graduate Committee: Laura BurklePlant-pollinator networks are threatened by anthropogenic influence due to habitat loss, changing fire regimes, climate change and other factors. Furthermore, we have little current knowledge for how species interactions and processes like pollination assemble and recover post-disturbance. Studying the mechanisms by which plant-pollinator interactions assemble in a post-disturbance landscape, particularly across gradients of disturbance intensity and successional time, would greatly help in building foundational ecological knowledge regarding the assembly of species interactions as well as provide specific information to aid conservation and management. Therefore, we investigated plant-pollinator network assembly after wildfire, between mixed- and high-severity burns and across time-since-burn, and we asked i) how do network structure and the network roles of persistent species vary ii) how does wildfire change the nutritional landscape of available floral pollen quality and how does that influence bumble bee foraging and nutrition, and iii) how do nesting and floral resources affected by wildfire influence wood-cavity-bee nesting success and richness? Our study design involved four wildfires from the Absaroka Mountains of southwest Montana, USA, which included a range of burn severities as well as a 1-25 year chronosequence of time-since-burn sampled primarily from 2014 to 2016. Bees were sampled via hand netting and nesting boxes alongside floral census transects and pollen sampling to assess metrics important to plant-pollinator network assembly, available floral pollen quality, bumble bee nutrition, and wood-cavity-nesting bee nesting success. The primary findings are that i) plant-pollinator network structure does not dramatically shift with burn severity or time-since-burn, nor do the network roles of persistent species, ii) available floral pollen quality and bumblebee nutrition are limited by high-severity burns, and iii) burn severity has little effect on the nesting success of wood-cavity-nesting bees. The conclusions that follow these results are mainly that i) evidence of constant structure and low variance of species' roles provides evidence for preferential attachment over opportunistic attachment in assembling plant-pollinator networks post-disturbance, ii) varied species composition between mixed- and high-severity burns may mean that bumble bees are nutritionally limited in high-severity burns, and iii) nesting resources do not appear to strongly limit nesting success or richness of wood-cavity-nesting bees.Item Nest site taphonomy of modern archosaurs(Montana State University - Bozeman, College of Letters & Science, 2016) Ferguson, Ashley Lynn; Chairperson, Graduate Committee: David Varricchio; David J. Varricchio, Carlos I. Piña and Frankie D. Jackson were co-authors of the article, 'From eggs to hatchlings: nest site taphonomy of American crocodile (Crocodylus acutus) and broad snouted caiman (Caiman latirostris)' submitted to the journal 'Palaios' which is contained within this thesis.; David J. Varricchio and Alex J. Ferguson were co-authors of the article, 'Nest site taphonomy of colonial ground nesting birds at Bowdoin National Wildlife Refuge' submitted to the journal 'Palaios' which is contained within this thesis.The goal of this thesis is to investigate the taphonomic processes that affect crocodylian and modern bird nesting localities in the hope that they would shed light into the identification of fossil nesting grounds and the interpretation of juvenile developmental stage. This project in particular observed nests of American crocodiles (Crocodylus acutus) at the Turkey Point Power Plant in Homestead, Florida, broad snouted caiman (Caiman latirostris) nests in the Northern Santa Fe and Chaco Provinces of Argentina, and colonial ground nesting birds (American white pelicans, double-crested cormorants, ring-billed and California gulls) at Bowdoin National Wildlife Refuge (BNWR) east of Malta, Montana. A major component of this project is the documentation of potentially preservable components, i.e., specimens (bones, eggshell, etc.) and structures (e.g. nesting traces) that might be represented in the fossil record. This thesis documents the agents and processes influencing bone and egg accumulations and nesting trace preservation across diverse biologies and environments.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 History, nesting biology, and predation ecology of raptors in the Missouri Coteau of northwestern North Dakota(Montana State University - Bozeman, College of Letters & Science, 1993) Murphy, Robert KevinItem The validity of using artificial nests to assess nest-predation rates in prairie nesting ducks(Montana State University - Bozeman, College of Letters & Science, 1996) Butler, Michael A.Item An investigation of factors that may affect nest success in CRP lands and other grassland habitats in an agricultural landscape(Montana State University - Bozeman, College of Letters & Science, 1996) Clawson, Mark R.Item Effects of ecological changes induced by various sagebrush control techniques on non-game birds(Montana State University - Bozeman, College of Letters & Science, 1970) Best, Louis Brown
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