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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.
1

Ecology of Greater Sage-Grouse Inhabiting the Southern Portion of the Rich-Morgan-Summit Sage-Grouse Management Area

Flack, M. Brandon 01 December 2017 (has links)
Greater sage-grouse (Centrocercus urophasianus; sage-grouse) are sagebrush obligates and are therefore considered to be key indicators of sagebrush ecosystem health. Sage-grouse populations have declined range-wide over the last century due to loss and fragmentation of sagebrush (Artemisia spp.) habitats. Sage-grouse populations found in large intact sagebrush landscapes are considered to be more resilient, however, some small isolated populations persist and thrive in fragmented landscapes. Because of Utah’s unique topography and geography, sage-grouse habitat is discontinuous and populations are naturally dispersed throughout the state in suitable intact blocks or in disconnected islands of sagebrush habitat. Thus, Utah populations provide the ideal place to understand how landscape attributes may influence at risk populations. Of these, the Morgan-Summit population is important because very little was known about the general ecology of this population and it experiences a high level of anthropogenic disturbances. I examined seasonal movement patterns, habitat selection, vital rates (nest initiation rates, nest success, clutch size, breeding success, brood success, and survival probability of breeding age birds) and the influence of vegetation components on vital rates of a small geographically isolated sage-grouse population in Morgan and Summit Counties in northern Utah from 2015–2016. To collect the data, I deployed 25 very-high frequency radio collars and 10 platform terminal transmitters and completed micro-site vegetation surveys at nest, brood, and paired random sites and then made comparisons. Nest sites exhibited variation in vegetation structure that influenced nest success, while brood sites did not. This population is one of the most productive in Utah exhibiting high nest initiation rates, hatching rates, and brood success rates despite limited habitat space and small seasonal movements. Transmitter type had no influence on vital rates, which is contrary to other studies, and limited influence on habitat selection. Sage-grouse avoided trees and developed areas, especially during the breeding season. Selection of other landscape variables was season-dependent. This information suggests that a sage-grouse population can occupy areas of limited habitat on an annual basis if seasonal habitat requirements are met. This study provides information that stake holders can utilize to conserve critical seasonal habitats within this study area where the population could be negatively affected by anthropogenic development pressure.
2

Winter Ecology of Common Ravens in Southern Wyoming and the Effects of Raven Removal on Greater Sage-Grouse Populations

Peebles, Luke W. 01 May 2015 (has links)
My research focused on common raven (Corvus corax; hereafter raven) winter ecology and removal, and how raven removal aids Greater sage-grouse (Centrocerus urophasiansu; hereafter sage-grouse) populations. Raven winter ecology in the western US has not been described in detail. I researched raven use of landfills for foraging and raven use of anthropogenic structures for roosting, as well as dispersal of ravens in the spring. In all 22% of radio-marked ravens (n=73) used landfills during the day, and 68%(n=73) roosted at anthropogenic roost sites during the evening. Correlations between landfill and roost counts of ravens were stronger (0.4>r<0.7) when the distance between these sites was <15 km, and smaller (r<0.3) when this distance >20 km. In the spring, ravens dispersed, on average, 38 km from landfills where they were caught. Large congregations of ravens at a few sites in winter may present opportunities to initiate raven population reduction methods to alleviate later problems. I analyzed raven survival and behaviour when USDA/APHIS Wildlife Services (WS) removed ravens using DRC-1339 during winter months. The number of ravens killed annually was 7-34% of the local population. Ravens did not avoid landfills, yet they switched roosts more frequently after an application of the toxicant. Raven removal improves sage-grouse nest success; however, data were not available to examine how raven removal improves sage-grouse abundance. I analyzed changes in raven density with regard to WS removal, and then related these changes with changes in sage-grouse lek counts the following year. Raven densities decreased by 50% from 2008-2014 where WS conducted removal programs. Sage-grouse lek counts improved in area where WS lowered raven abundance, in comparison to areas farther away, during the latter half of the study (2013-2015), when WS removal efforts intensified. Thereafter, a 10% decline in raven abundance was associated with a 2% increase in sage-grouse lek counts. Overall, ravens in souther Wyoming used anthropogenic resources during the winter, and removal of ravens at these locations, combined with removal in the spring, minimally impacted raven populations annually and was associated with increases in sage-grouse abundance.
3

Greater Sage-Grouse and Energy Development in Northeastern Utah: Implications for Management

Smith, Leah Suzanne 01 May 2009 (has links)
Concern regarding the effect of energy development on greater sage-grouse (Centrocercus urophasianus) is increasing as the search for fossil fuel intensifies. Sage-grouse may be especially sensitive to energy development because they require large, diverse areas of sagebrush (Artemisia spp.) habitat to complete their life cycle. Additionally, the network of pipelines, roads, and wells required by energy development may fragment sagebrush habitat isolating populations and contributing to genetic drift, inbreeding, local extinction, or rapid divergence. Seep Ridge, located in northeastern Utah, is one area where sage-grouse habitat and energy development plans overlap. Approved leases call for the construction of an additional 4,000 natural gas wells in an area currently occupied by a small sage-grouse population. This research was completed to 1) collect baseline data on the survival, reproductive success and habitat use of the Seep Ridge sage-grouse population, 2) examine sage-grouse habitat use patterns in relation to development, and 3) describe sage-grouse mitochondrial genetic diversity in 3 northeastern Utah populations relative to other parts of the species range. I captured and monitored 16 sage-grouse from the Seep Ridge population in 2007 and 2008. Adult mortality rate of the Seep Ridge population was high (65.2%) and recruitment was low (7.1%) compared to other sage-grouse populations in Utah. Additionally, the monitored sage-grouse used habitats located farther from wells more frequently than habitat located near wells, relative to well spacing. Current habitats occupied by this population do not meet recommended guidelines. No unusual haplotype compositions were observed in the genetic survey of the northeastern Utah sage-grouse populations. However, differences in haplotype composition between the Anthro Mountain and Strawberry Valley populations and other northeastern grouse populations indicate there may be a barrier to gene flow in the area. I also documented that the Seep Ridge population is connected to another population inhabiting Ute Tribal land. This observation suggests that the populations inhabiting Ute Tribal land may constitute a source population to recolonize Seep Ridge during the post-energy development periods. I recommend that mitigation measures incorporate restricting development in breeding habitat, maintaining connections between populations, and actions to reduce adult mortality on the summer range. I also recommend that biologists continue collecting genetic samples from northeastern Utah sage-grouse populations to understand population structure, divergent evolution, and inform decisions concerning translocation
4

Understanding the Interaction Between Habitat Use of Feral Horses and the Abundance of Greater Sage-Grouse in the Great Basin

Carver, Mikiah R. 21 July 2021 (has links)
Environmental impacts of feral horses (Equus caballus) are a subject of conservation concern and controversial national policy. In North America, feral horses are considered an invasive species where they impact rangelands of the arid and semi-arid western United States. The greater sage-grouse (Centrocercus urophasianus) is a native sagebrush obligate bird species that relies on sagebrush habitats to sustain viable population levels. Recent literature suggests that feral horse presence can have a notable effect on the fitness of native and sagebrush obligate species throughout the arid and semi-arid western United States. The purpose of this thesis was to assess the potential impact of feral horses on population patterns and on late-brood rearing habitat of greater sage-grouse throughout the Great Basin. This was accomplished by pairing known sage-grouse use sites (leks and late brood-rearing habitat) to random sites for comparison. Within each pair, one site was located within Herd Management Area (HMA) boundaries (with assumed horse presence) while the other was located outside (with assumed horse absence). We then assessed lek attendance throughout the state of Nevada and compared attendance rates to known horse population estimates. Furthermore, paired late brood-rearing habitat sites were compared to one another to assess the effect of horse and cattle presence on habitat quality and characteristics. We determined that mean sage-grouse population size at leks is higher (9.14 ± 1.04 males) within HMA boundaries compared to areas outside of HMA boundaries (6.55 ± 0.74 males). Considering late brood-rearing habitat, we determined that statistical differences have occurred between horse and non-horse use sites in the following comparisons: annual grass frequency, percent annual grass cover, dung frequency, total plant height, vegetative height, and horse and cattle dung density. We suggest that feral horse presence can impact sage-grouse habitat, however, a more clear understanding of horse effects on rangeland wildlife habitat is needed to assess actual impacts on wildlife populations in consideration of multiple use management decisions.
5

Effects of Livestock Grazing Management Practices on Greater Sage-Grouse Nest and Female Survival

Dettenmaier, Seth J. 01 August 2018 (has links)
The decline in greater sage-grouse (Centrocercus urophasianus; sage-grouse) populations across western North America has been primarily attributed to loss and fragmentation of their sagebrush (Artemisia spp.) habitats. This habitat loss is largely the result of increased human activities, with grazing by domestic livestock as the most predominant land use across the sagebrush ecosystem in North America. The goal of my research was to increase our understanding of the effects of livestock on sage-grouse populations. I reviewed the peer-reviewed literature for all published studies that reported potential effects of grazing on grouse species worldwide. I found that there was an overall negative effect of domestic livestock grazing on grouse populations in general. I compared sage-grouse nest success on two study sites managed under differing prescribed livestock grazing practices to determine their relative effects on sage-grouse nest survival. I found that nest survival was slightly higher in areas managed under high-intensity low-frequency rest-rotation practices. The difference was not statistically significant (P < 0.05). However, these areas received lower precipitation and were grazed at a higher stocking rate (AUM · ha-1) without negatively affecting nest survival compared to areas of that were mostly grazed as single pastures from May-September. Because livestock grazing in the sagebrush ecosystem has been historically facilitated with sagebrush reduction treatments to increase forage for livestock, I compared the relative effects of these treatments with the more direct effect from livestock grazing. Sagebrush treatments were found to have a greater effect on female sage-grouse survival than livestock grazing. This understanding can be useful for land managers looking to attenuate the effects of management decisions related to livestock grazing systems in the sagebrush ecosystem.
6

Factors Affecting Greater Sage-Grouse (Centrocercus Urophasianus) Survival and Movement in South-Central Utah

Caudill, Danny 01 May 2011 (has links)
Greater sage-grouse (Centrocercus urophasianus) adult and juvenile survival have been identified as critical demographic parameters. However, little is known regarding the dynamics of juvenile sage-grouse. From 2008-2010, I used radio-telemetry and 2 transmitter types to monitor 91 juvenile sage-grouse. Program MARK was used to analyze survival data. Over-winter survival was 0.802 - 0.982 and 0.687 - 0.969 for females and males, respectively. Fall survival rates were 0.522 - 0.623 for females and 0.332 - 0.449 for males. Survival from fall through winter was 0.418 - 0.616 for females and 0.228 - 0.435 for males. For both years combined, the probability predation caused death was 0.705, and probability harvest caused death was 0.159. The probability unreported harvest caused death was 0.091. Sex (p= 0.103) and transmitter type (p = 0.09) affected survival. Back-mounted transmitters negatively affected survival and their use should be avoided to minimize experimental bias.
7

Factors Affecting Gunnison Sage-Grouse (<i>Centrocercus minimus</i>) Conservation in San Juan County, Utah

Prather, Phoebe R. 01 December 2010 (has links)
Due to loss of habitat, Gunnison sage-grouse (Centrocercus minimus) currently occupy 8.5% of their presumed historical range. One population survives in Utah, occurring in San Juan County. The Gunnison Sage-grouse Rangewide Conservation Plan and the San Juan County Gunnison Sage-grouse Conservation Plan recommended management strategies to address identified conservation threats to the Utah population. I addressed three conservation strategies identified in the plans: 1) creation and enhancement of brood-rearing areas; 2) assessment of habitat conditions within the Gunnison Sage-grouse Conservation Area; and 3) prevention or reduction of perching events by avian predators on distribution line power poles. From 2007-2009, I addressed the conservation strategy of creating mesic brood-rearing areas in Conservation Reserve Program fields and native sagebrush areas by evaluating the role of irrigation and dormant season cattle grazing on habitat. Vegetation and arthropod diversity in irrigated versus non-irrigated plots did not differ (p>0.01). Conservation Reserve Program plots exhibited greater arthropod abundance and cover of perennial grass than the native sagebrush plots, but lower diversity of perennial grasses and abundance and diversity of forbs (p<0.01). The second conservation strategy I addressed was the completion of an assessment of habitat conditions within the Gunnison Sage-grouse Conservation Area. I measured vegetation conditions within habitat occupied and unoccupied by Gunnison sage-grouse. Cover and height of grasses exceeded guidelines for occupied and unoccupied habitats. Forb cover was below recommended guidelines in occupied habitat. Sagebrush cover was below guidelines for winter habitat. Habitat restoration efforts should focus on retaining existing sagebrush cover and establishment of sagebrush, forb, and grass cover within Conservation Reserve Program fields. The third conservation strategy I evaluated was the retrofitting of distribution line power poles with perch deterrents to discourage avian predators from perching. I evaluated the efficacy of five perch deterrents. The perch deterrents did not mitigate potential avian predators from perching. A deterrent designed for insulators, in combination with physical deterrents we tested, has potential to prevent perching. These studies provided a sound first step that can be built upon by the Monticello/Dove Creek Local Working Group to improve habitat conditions, reduce the threat of avian predation, and plan future conservation activities within the Conservation Area.
8

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.
9

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.
10

Seasonal Habitat Selection by Greater Sage Grouse in Strawberry Valley Utah

Peck, Riley D. 09 December 2011 (has links) (PDF)
This study examined winter habitat use and nesting ecology of greater sage grouse (Centrocercus urophasianus) in Strawberry Valley (SV), Utah located in the north-central part of the state. We monitored sage grouse with the aid of radio telemetry throughout the year, but specifically used information from the winter and nesting periods for this study. Our study provided evidence that sage grouse show fidelity to nesting areas in subsequent years regardless of nest success. We found only 57% of our nests located within the 3 km distance from an active lek typically used to delineate critical nesting habitat. We suggest a more conservative distance of 10 km for our study area. Whenever possible, we urge consideration of nest-area fidelity in conservation planning across the range of greater sage grouse. We also evaluated winter-habitat selection at multiple spatial scales. Sage grouse in our study area selected gradual slopes with high amounts of sagebrush exposed above the snow. We produced a map that identified suitable winter habitat for sage grouse in our study area. This map highlighted core areas that should be conserved and will provide a basis for management decisions affecting Strawberry Valley, Utah.

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