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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Reproductive Ecology of Greater Sage-Grouse in Strawberry Valley, Utah

Baxter, Jared Jeffrey 01 December 2016 (has links)
Greater sage-grouse (Centrocercus urophasianus; hereafter, sage-grouse) are a species of conservation concern in the rangelands of western North America due to their dramatic decline over the last half century. Effective conservation and management of sensitive species requires an understanding of how species respond to management actions. We examined two aspects of the reproductive phases of sage-grouse: nest predation, and habitat selection by female sage-grouse with chicks. In Chapter 1, we developed resource selection functions to assess the influence of mechanical treatments of mountain big sagebrush (Artemisia tridentata vaseyana) on habitat selection by greater sage-grouse with chicks. Post-treatment sage-grouse showed stronger selection for treatments and treatment edges than did pre-treatment sage-grouse. This altered pattern of selection by sage-grouse with broods suggests mechanical treatments may be a suitable way to increase use of mountain big sagebrush during the brooding period. In Chapter 2, we assessed the effect of habitat edges on nest predation of sage-grouse. The "edge effect" hypothesis states that habitat edges are associated with reduced nest success for birds. We tested the edge effect hypothesis using 155 nest locations from 114 sage-grouse. We derived edge metrics for 11 habitat cover types to determine which variables may have affected nest predation. We found support for the edge effect hypothesis in that nest predation increased with increasing edge density of paved roads. We provide evidence that the edge effect hypothesis may apply to greater sage-grouse and their habitats. Based on our results, we recommend minimizing disturbances that fragment critical nesting habitat of greater sage-grouse.
12

Ecology and Management of a High Elevation Southern Range Greater Sage-Grouse Population: Vegetation Manipulation, Early Chick Survival, and Hunter Motivations

Guttery, Michael R. 01 December 2010 (has links)
My research provided new information concerning the management, ecology, and conservation of greater sage-grouse (Centrocercus urophasianus). I report the results of an experiment using strategic intensive sheep grazing to enhance the quality of greater sage-grouse brood-rearing habitat. Although forb cover, an important component of brood-rearing habitat, responded positively to the grazing treatment, the response of other habitat variables was suppressed because the plots were not protected from domestic and wild herbivores during the years following the treatments. Measurements taken in grazing exclosures confirmed that herbivory by both large and small animals had significant impacts on vegetation. However, despite the suppressed habitat response, sage-grouse preferred the treated plots over the controls. In another chapter, I modeled survival rates of sage-grouse chicks to 42-days of age. Average chick survival across my study was high (39%). Survival varied across years and was affected by demographic, behavioral, and habitat factors. The top habitat model indicated that chick survival was positively related to grass cover and was higher in areas dominated by black sagebrush (Artemisia nova) than in big sagebrush (A. tridentata). The top model with demographic/behavioral factors indicated that survival was affected by interactions between hen age and brood mixing as well as between hatch date and brood mixing. In my last chapter I report on a survey of Utah sage-grouse hunter motivations and satisfaction. In 2008 and 2009 I surveyed over 600 sage-grouse hunters in Utah to determine why they chose to apply for sage-grouse hunting permits and what factors contributed to a satisfactory hunting experience. Originally, I had hypothesized that the impending Endangered Species Act listing petition for greater sage-grouse motivated hunters to pursue the species before they lost the opportunity. This hypothesis was not supported by the data. The majority of hunters indicated that they chose to hunt sage-grouse because it was a tradition or because it provided an opportunity to spend time outdoors with family. Additionally, Utah sage-grouse hunter satisfaction was influenced by whether or not the hunter was successful in harvesting at least one bird.
13

Population Dynamics and Movements of Translocated and Resident Greater Sage-Grouse on Anthro Mountain, Utah

Gruber, Natasha W. 01 December 2012 (has links)
Declining populations of greater sage-grouse (Centrocercus urophasianus; hereafter sage-grouse) have increased stakeholder concerns regarding the management and stability of the species range-wide. Numerous conservation strategies have been identified to restoring sage-grouse population declines to include species translocations. Translocations have been used for many different wildlife species to help sustain genetic heterogeneity, reestablish, and augment declining populations. In a recent translocation study, researchers identified the protocols used to successfully translocate sage-grouse to restore declining populations in Strawberry Valley, Utah. This translocation occurred in a high elevation basin buffered by geomorphic barriers. I evaluated these protocols for use in translocating sage-grouse to augment a declining population that inhabited Anthro Mountain in northwest Utah. Anthro Mountain is a high elevation mountain dominated by sagebrush (Artemisia spp.) void of geomorphic barriers. I compared annual production, survival (i.e., vital rates), habitat use, and movements of translocated birds and their progeny to the resident population. Lastly, I described the integration of translocated birds with resident birds and the overall efficacy of the translocation effort. I radio-collared and monitored 60 translocated female sage-grouse from Parker Mountain, Utah over a 2-year period (2009 and 2010) and compared their vital rates to 19 radio-marked resident sage-grouse. Adult survival was similar for resident and translocated birds, but higher for both groups in 2010 than in 2009. However, overall survival of both resident and translocated birds was lower than range-wide survival estimates. Nest success was slightly higher for resident birds than translocated birds but positively correlated to grass height for both groups. Chick survival was also slightly higher for resident birds than for translocated birds, and higher overall in 2010 than in 2009. Chick survival was positively correlated to grass cover for both groups. Translocated birds used similar habitats and exhibited migration behaviors similar to resident birds. From a methodology perspective, the translocations protocols were successful because the translocated birds quickly acclimated to the release area, and their survival and reproductive success were similar to the resident birds. The effect of the translocation on augmenting the local population was inconclusive.
14

Common Raven Density and Greater Sage-Grouse Nesting Success in Southern Wyoming: Potential Conservation and Management Implications

Dinkins, Jonathan B 01 August 2013 (has links)
My research was focused on greater sage-grouse (Centrocercus urophasianus; hereafter "sage-grouse") nest-site selection, nest success, and hen survival in relation to avian predators. The trade-off between using habitat and avoiding predators is a common decision for prey species including sage-grouse. In Chapter 2, I compared avian predator densities at sage-grouse nest and brood locations to random locations. Sage-grouse were located where densities of small, medium, and large avian predators were 65-68% less than random locations. The effects of anthropogenic and landscape features on habitat use of sage-grouse hens have not been evaluated relative to avian predator densities. In Chapter 3, I compared anthropogenic and landscape features and avian predator densities among sage-grouse locations (nest, early-brood, late-brood) and random locations. I found sage-grouse hens chose locations with lower avian predator densities compared to random locations, and selected locations farther away from anthropogenic and landscape features. Depredation of sage-grouse nests can be an influential factor limiting their productivity. Predator removal has been simultaneously proposed and criticized as a potential mitigation measure for low reproductive rates of sage-grouse. In Chapter 4, I hypothesized that sage-grouse nest success would be greater in areas where Wildlife Services lowered common raven (Corvus corax: hereafter "raven") density. I found that Wildlife Services decreased raven density by 61% during 2008-2011 but I did not detect a direct improvement to sage-grouse nest success. However, sage-grouse nest success was 22% when ravens were detected within 550 m of a sage-grouse nest and 41% when no raven was detected within 550 m. In Chapter 5, I assessed interactive effects of corvid densities relative to anthropogenic and landscape features on sage-grouse nest success. I found that sage-grouse nest success was positively correlated with rugged habitat. Survival of breeding-age birds is the most important demographic parameter driving sage-grouse abundance. In Chapter 6, I evaluated the effect of raptor densities, proximity to anthropogenic and landscape features, and hen behavior on survival of sage-grouse hens. I found that sage-grouse hen survival was negatively correlated with golden eagle (Aquila chrysaetos) density, proximity to anthropogenic and landscape features, and hen parental investment (nesting and brood-rearing).
15

Greater Sage-Grouse Seasonal Habitat Models, Response to Juniper Reduction and Effects of Capture Behavior on Vital Rates, in Northwest Utah

Cook, Avery 01 May 2015 (has links)
The greater sage-grouse (Centrocercus urophasianus; sage-grouse) is a species of conservation concern in Utah and range-wide due to declines in populations and threats to sagebrush habitat on which they depend. To effectively conserve the species, detailed site-specific knowledge of ecology and distribution is needed. To expand knowledge of local populations within the West Box Elder Sage Grouse Management Area (SGMA) and gain insights into the effectiveness of vegetation treatments intended to benefit sagegrouse, I radio marked and tracked 123 (68 female, 55 male) sage-grouse and conducted sage-grouse pellet surveys on 19 conifer removal projects. Widespread habitat restoration measures designed to benefit sage-grouse have highlighted the need for prioritization tools to optimize placement of sage-grouse habitat projects. I generated seasonal habitat models to predict sage-grouse habitat use within the West Box Elder SGMA using a suite of vegetation and topographical predictors and known sage-grouse locations. Model fit was good with brood, early summer, late summer, lekking (early spring), and non-breeding models reporting an AUC of >0.90; nest and winter models reported an AUC of 0.87 and 0.85, respectively. A vegetation disturbance history was built for the study area from 1985 to 2013; however, the vegetation disturbances mapped were not a strong predictor of sage-grouse seasonal habitat-use. To evaluate effectiveness of conifer reduction treatments I used fecal pellet and in concert with radio-telemetry data. Increased sage-grouse use of conifer treatments was positively associated with sage-grouse presence in adjacent habitats (P = 0.018), percent shrub cover (P = 0.039), and mesic environments within 1000 m of treatments (P = 0.048). Sage-grouse use of conifer treatments was negatively associated with conifer canopy cover (P = 0.048) within 1000 m of treatments. To investigate sample bias related to individual bird behavior or capture trauma I monitored 204 radio-marked sage-grouse within the West Box Elder and Rich-Morgan- Summit SGMAs in Utah between January 2012 and March 2013. Sage-grouse that flushed one or more times prior to capture had higher brood (P = 0.014) and annual survival (P = 0.027) than those that did not. Sage-grouse that experienced more capture trauma had decreased annual survival probabilities (P = 0.04).
16

Ecology of Isolated Greater Sage-Grouse Populations Inhabiting the Wildcat Knolls and Horn Mountain, Southcentral Utah

Perkins, Christopher J. 01 May 2010 (has links)
Greater sage-grouse (Centrocercus urophasianus) currently inhabit about 56% of pre-settlement distribution of potential habitat. In 2005, the Castle Country Adaptive Resources Management Local Working Group (CaCoARM) was formed to address concerns regarding local sage-grouse populations in Carbon and Emery counties. In 2006-2007, CaCoARM identified the Wildcat Knolls and Horn Mountain as areas of special concern for greater sage-grouse conservation. Both sites selected by the group were inhabited by what appeared to be small isolated sage-grouse populations. Factors limiting small isolated greater sage-grouse populations throughout its range are diverse and largely site-specific. During 2008-2009, I captured, radio-collared, and monitored 43 sage-grouse between the two populations to document their ecology and seasonal habitat use patterns. The sites are only 24 km apart, but the populations appear to be isolated from each other. Sage-grouse on Horn Mountain and Wildcat Knolls are one-stage migratory and non-migratory, respectively. Although nesting and brooding success varied between sites, my results were comparable to those published in studies throughout the species' range. Overall male survival was lower on the Wildcat Knolls than Horn Mountain (P = 0.003). Hens that selected brood sites exhibiting increased shrub cover and grass height were more successful than hens that selected sites with lower shrub cover and lower grass height. Potential nesting habitat on the Wildcat Knolls and Horn Mountain were estimated at 2,329 and 5,493 ha, respectively. Hens that selected nest sites farther from non-habitat edge were more successful than hens that selected nest sites that were closer to non-habitat edge on the Wildcat Knolls. Higher nest success observed on the Wildcat Knolls was attributed to less habitat fragmentation. Isolated populations of greater sage-grouse are more susceptible to lower amounts of genetic diversity that may lead to inbreeding depression and increased rates of disease and parasites. I collected mitochondrial DNA samples from both the Wildcat Knolls and Horn Mountain populations. Although the haplotype frequencies recorded in the Wildcat Knolls and Horn Mountain populations were low, one was shared with several Utah populations. The documented low genetic diversity (especially on Horn Mountain) confirmed the isolation suspected by the local working group. Microsatellite tests may provide insights to enhance understanding of genetic differences among sites, and assist managers in determining whether or not translocations are necessary to maintain population genetic diversity. Biologists should not only continue to take samples for genetic comparison, but also record morphometric and behavior data.
17

Population Genetics of Greater Sage-Grouse in Strawberry Valley, Utah

Dunken, Paula S. 01 July 2014 (has links) (PDF)
This study examined population genetics of greater sage-grouse (Centrocercus urophasianus) in Strawberry Valley, Utah located in the north-central part of the state. The Strawberry Valley population of sage-grouse experienced a severe population decline with estimates of abundance in 1998 less than 5% (~150 individuals) of similar estimates from the 1930s (>3,000 individuals). Given the population decline and reduced genetic diversity, recovery team partners translocated sage-grouse from four different populations into Strawberry Valley over 6 years (2003-2008). Translocations have been used as a strategy to increase both population size and genetic diversity in wildlife populations. We assessed whether genetic diversity increased following the translocation of sage-grouse into Strawberry Valley by looking at both nuclear and mitochondrial DNA indices. We observed an overall increase of 16 microsatellite alleles across the 15 loci studied (x̅ =1.04 alleles per locus increase, SE ± 0.25). Haplotype diversity increased from 4 to 5. Levels of genetic diversity increased for both nuclear and mitochondrial DNA (16% and 25% increases for allelic richness and haplotype diversity, respectively). These results show that translocations of greater sage grouse into a wild population can be an effective tool to increase not only population size but also genetic diversity.Second, we studied fitness-related traits and related them to genetic diversity indices in a population of greater sage-grouse in Strawberry Valley, Utah from 2005 to 2013. We captured 93 sage-grouse in Strawberry Valley and fitted them with a radio collar and drew and preserved blood. We monitored sage-grouse weekly, throughout each year. From blood, we extracted and amplified DNA with 15 microsatellite loci. We determined genetic diversity as multilocus heterozygosity and mean d2. To determine if there was a relationship between genetic diversity and survival, we used known-fate models in Program MARK. We also determined if there was a relationship between genetic diversity measures and nest initiation, nest success, clutch size, and number of eggs hatched using generalized linear models where reproductive measures were modeled as a function of genetic diversity. We found no significant relationship between mean d2 and microsatellite heterozygosity with measures of survival or reproductive fitness. Overall, these results suggest that the often-reported strong heterozygosity-fitness correlations detected in small, inbred populations do not reflect a general phenomenon of increasing individual survival and reproductive fitness with increasing heterozygosity.
18

The Effects of Dixie Harrow Treatments on Greater Sage-grouse Resource Selection and the Nutritional Value of Sagebrush During Winter

Wood, Jason Alan 01 April 2019 (has links)
Sagebrush (Artemisia spp.) is an important source of food and cover for many animals, especially during winter months. Understanding how wildlife species respond to sagebrush management actions can help improve conservation planning. Dixie harrow is a method of improving spring/summer habitat for many herbivores by reducing sagebrush cover to stimulate the growth of grasses and forbs. These treatments, however, may influence the quantity and quality of sagebrush available to greater sage-grouse (Centrocercus urophasianus; hereafter, sage-grouse) during winter. We evaluated the effects of Dixie harrow on sage-grouse resource selection during winter (Chapter 1) and on the nutritional value of sagebrush (Chapter 2). We were unsure what effect Dixie harrow would have on the nutritional value of sagebrush, but hypothesized that sage-grouse would select for untreated areas because they contained a higher quantity of food and cover. We captured 81 sage-grouse and fit them with GPS transmitters. Using 6,728 winter locations, we modeled third-order resource selection. Further, we collected samples of sagebrush plants that sage-grouse had eaten from (n = 54), samples of sagebrush plants passed by but not eaten from (n = 54), as well as samples from random locations inside (n = 60) and outside Dixie harrow treatments (n = 60). Contrary to our hypothesis, sage-grouse selected for Dixie harrow treatments during winter. We found that sage-grouse selectively browsed sagebrush plants with increased nutritional value, and that sage-grouse browsed plants inside treatments more frequently than outside the treatments, but Dixie harrow treatments had no measurable effect on the nutritional value of sagebrush. Based on our results, Dixie harrow treatments performed at the southern extent of the sage-grouse range will create habitat that sage-grouse prefer during winter, but we were unable to ascertain why sage-grouse select for Dixie harrow treatments during winter.
19

The Emergence of the Wyoming Core Area Strategy: "The Sage Grouse Rebellion"

Trefren, Jennie Lee 05 June 2012 (has links)
This research sought to explain the emergence of the Wyoming Core Area Strategy (WCAS), a state-based Greater Sage Grouse conservation plan. It presents a theoretical framework that is based on and adds nuance to the Advocacy Coalition Framework (ACF). The hypothesis this study explored was: if a subsystem's jurisdiction is threatened by a hierarchically superior subsystem's policy outputs and this jurisdiction is necessary to meet the threatened subsystem's goals, then policy change may occur as a result of a strategy by the agents in the threatened subsystem. The data used to examine the hypothesis included expert interviews, historical documents, and interviews from media sources (secondary source interviews). The hypothesis was supported; the WCAS emerged because the Endangered Species Act listing outputs within the Species Conservation Policy Subsystem threatened the Wyoming Land Use Policy (WLUP) Subsystem's jurisdiction, which was necessary to meet the WLUP Subsystem's economic and lifestyle goals; the Governor of Wyoming drove the development and enactment of the WCAS as a strategy to retain jurisdiction. The research demonstrated that in order to fully account for the WCAS's emergence, a less mechanistic view of the framework, one that accounts for the ability of agents in a subsystem to act strategically, was needed. The research also demonstrated that the Greater Sage Grouse conservation benefited from the ESA listing process despite its warranted but precluded listing status. The time frame the research explored was 2002 through March 2012. / Master of Arts
20

Informing Conservation Management Using Genetic Approaches: Greater Sage-Grouse and Galápagos Short-Eared Owls as Case Studies

Schulwitz, 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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