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Habitat Selection of Greater Sage-Grouse Centrocercus urophasianus and Northern River Otters Lontra canadensis in UtahWestover, Matthew D. 06 December 2012 (has links) (PDF)
Greater sage-grouse populations have decreased steadily since European settlement in western North America. Reduced availability of brood-rearing habitat has been identified as a limiting factor for many populations. We used radio-telemetry to acquire locations of sage-grouse broods from 1998 to 2012 in Strawberry Valley, Utah. Using these locations and remotely-sensed imagery, we proceeded to 1) determine which features of brood-rearing habitat could be identified using widely available, fine-scale imagery 2) assess the scale at which sage-grouse selected brood-rearing habitat in our study area, and 3) create a predictive habitat model that could be applied across our large study area to identify areas of preferred brood-rearing habitat. We used AIC model selection to evaluate support for a list of variables derived from remotely-sensed imagery. We examined the relationship of explanatory variables at three scales (45, 200, and 795 meter radii). Our top model included 10 variables (percent shrub, percent grass, percent tree, percent paved road, percent riparian, meters of sage/tree edge, meters of riparian/tree edge, distance to tree, distance to transmission lines, and distance to permanent structures). Variables from each scale were represented in our top model with the majority of scale-sensitive variables suggesting selection at the larger (795 meter) scale. When applied to our study area our top model predicted 75% of naive brood locations suggesting reasonable success using this method and widely available NAIP (National Agricultural Imagery Program) imagery. We encourage application of this method to other sage-grouse populations and species of conservation concern. The northern river otter is a cryptic semi-aquatic predator that establishes and uses latrines. Highly used river otter latrines indicate otter "activity centers" since frequency of scat deposition is thought to be correlated to frequency of habitat use. We compared an indirect method (scat counts) and a direct method (remote cameras) of determining latrine utilization in order to assess the accuracy of the commonly used indirect method. To further compare these methods we used them to examine effects of anthropogenic disturbance on otters of the Provo River in Utah. We found that overall the direct and indirect methods were highly correlated. There was significant seasonal variation in the degree of correlation between the indirect and direct methods with correlation being significantly higher in the summer. We found similar results when using these methods to examine effects of anthropogenic disturbance. For each method the distance of the latrine to trails was significant in one of the top competing models. We suggest that space use of otters in our study area is being affected by anthropogenic disturbance as measured by distance to trails. We also suggest that scat counts should only be conducted during the summer when they correlate best with actual levels of otter activity.
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Landscape management for a landscape species: Understanding the impacts of anthropogenic factors on sage-grouse populations in WyomingSpence, Emma Suzuki 28 April 2017 (has links)
No description available.
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Conservation and Management of Greater Sage-Grouse in Strawberry Valley: Quantifying Influences on a Traditional Capture Method and Long-Term Trends in Clutch SizeRadke, Janae 25 April 2024 (has links) (PDF)
The greater sage-grouse (Centrocercus urophasianus) is a species of conservation concern that has undergone serious declines in the last century. The Strawberry Valley sage grouse population in Utah underwent such a decline from an estimated 3,500 sage grouse in the 1930s to 150 sage grouse in the early 2000s. This decline initiated a long-term conservation and monitoring project in Strawberry Valley with the goal of preserving the sage grouse population. As part of this ongoing conservation project, we investigated factors that impact the success of capturing sage grouse using the night-lighting method (Chapter 1). We found that capture success is influenced by precipitation, frost, vegetation, flock size, capture crew size, mode of transportation, and sex of the sage grouse. We provide information on these influential factors as well as recommendations on equipment and technique. We also compiled a dataset beginning in the 1930s of sage grouse clutch sizes from the Strawberry Valley population to determine the average number of eggs per clutch (Chapter 2). We investigated average clutch size over time, factors that influence average clutch size, and the accuracy and reliability of our clutch size counts. We found yearly variation in average clutch size that shows a weak, positive correlation with population size. Clutch sizes were smaller if laid as a re-nest or by sage grouse recently translocated from a different population. We found evidence that some of our clutch size counts are approximately two eggs fewer than the actual number laid by the sage grouse.
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Informing Conservation Management Using Genetic Approaches: Greater Sage-Grouse and Galápagos Short-Eared Owls as Case StudiesSchulwitz, Sarah E. 05 1900 (has links)
Small isolated populations are of particular conservation interest due to their increased extinction risk. This dissertation investigates two small wild bird populations using genetic approaches to inform their conservation. Specifically, one case study investigated a Greater Sage-grouse (Centrocercus urophasianus) population located in northwest Wyoming near Jackson Hole and Grand Teton National Park. Microsatellite data showed that the Jackson sage-grouse population possessed significantly reduced levels of neutral genetic diversity and was isolated from other Wyoming populations. Analysis with single nucleotide polymorphisms (SNPs) and microsatellite data provided further evidence that the population's timing of isolation was relatively recent and most likely due to recent anthropogenic habitat changes. Conservation recommendations include maintaining or increasing the population's current size and reestablishing gene flow with the nearest large population. The second case study investigated the genetic distinctiveness of the Floreana island population of the Galápagos Short-eared Owl (Asio flammeus galapagoensis). Mitochondrial DNA sequence data did not detect differences across nine island populations, yet microsatellite and morphometric data indicated that limited gene flow existed with the population and surrounding island populations, which appeared asymmetric in direction from Floreana to Santa Cruz with no indication of gene flow into Floreana. These results have important conservation implications and recommend that the Floreana Short-eared Owl population be held in captivity during the rodenticide application planned for an ecosystem restoration project in 2018. The population is less likely to receive immigrants from surrounding island populations if negatively effected by feeding on poisoned rodents.
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