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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.
421

Microhabitat and Movement Assessment for Northern Mexican Gartersnakes (Thamnophis eques megalops) at Bubbling Ponds Hatchery, Arizona

January 2017 (has links)
abstract: Species conservation requires an understanding of the habitats on which that species depends as well as how it moves within and among those habitats. Knowledge of these spatial and temporal patterns is vital for effective management and research study design. Bubbling Ponds Hatchery in Cornville, Arizona, supports a robust population of the northern Mexican gartersnake (Thamnophis eques megalops), which was listed as threatened under the Endangered Species Act in 2014. Natural resource managers are interested in understanding the ecology of gartersnakes at this site to guide hatchery operations and to serve as a model for habitat creation and restoration. My objectives were to identify habitat selection and activity patterns of northern Mexican gartersnakes at the hatchery and how frequency of monitoring affects study results. I deployed transmitters on 42 individual gartersnakes and documented macro- and microhabitat selection, daily and seasonal activity patterns, and movement distances. Habitat selection and movements were similar between males and females and varied seasonally. During the active season (March–October), snakes primarily selected wetland edge habitat with abundant cover and were more active and moved longer distances than during other parts of the year. Gestating females selected similar locations but with less dense cover. During the inactive season (November–February), snakes were less mobile and selected upland habitats, including rocky slopes with abundant vegetation. Snakes displayed diurnal patterns of activity. Estimates of daily distance traveled decreased with less-frequent monitoring; a sampling interval of once every 24 hours yielded only 53–62% of known daily distances moved during the active season. These results can help inform management activities and research design. Conservation of this species should incorporate a landscape-level approach that includes abundant wetland edge habitat with connected upland areas. Resource managers and researchers should carefully assess timing and frequency of activities in order to meet project objectives. / Dissertation/Thesis / Masters Thesis Applied Biological Sciences 2017
422

Statistical evaluation and GIS model development to predict and classify habitat quality for the endangered Southwestern Willow Flycatcher

January 2013 (has links)
abstract: The Southwestern Willow Flycatcher (Empidonax traillii extimus) has been studied for over two decades and listed as endangered for most of that time. Though the flycatcher has been granted protected status since 1995, critical habitat designation for the flycatcher has not shared the same history. Critical habitat designation is essential for achieving the long-term goals defined in the flycatcher recovery plan where emphasis is on both the protection of this species and "the habitats supporting these flycatchers [that] must be protected from threats and loss" (U.S. Fish and Wildlife Service 2002). I used a long-term data set of habitat characteristics collected at three study areas along the Lower Colorado River to develop a method for quantifying habitat quality for flycatcher. The data set contained flycatcher nest observations (use) and habitat availability (random location) from 2003-2010 that I statistically analyzed for flycatcher selection preferences. Using both Pearson's Chi-square test and SPSS Principal Component Analysis (PCA) I determined that flycatchers were selecting 30 habitat traits significantly different among an initial list of 127 habitat characteristics. Using PCA, I calculated a weighted value of influence for each significant trait per study area and used those values to develop a habitat classification system to build predictive models for flycatcher habitat quality. I used ArcGIS® Model Builder to develop three habitat suitability models for each of the habitat types occurring in western riparian systems, native, mixed exotic and exotic dominated that are frequented by breeding flycatchers. I designed a fourth model, Topock Marsh, to test model accuracy on habitat quality for flycatchers using reserved accuracy assessment points of previous nest locations. The results of the fourth model accurately predicted a decline in habitat at Topock Marsh that was confirmed by SWCA survey reports released in 2011 and 2012 documenting a significant decline in flycatcher productivity in the Topock Marsh study area. / Dissertation/Thesis / M.S. Applied Biological Sciences 2013
423

Changes in diet resource use by elephants, Loxodonta Africana, due to changes in resource availability in the Addo National Park

Du Toit, Jana January 2015 (has links)
Animals are restricted in their diets by several factors, most notably the availability and quality of resources. Variation in resource availability causes herbivores to shift their diets seasonally and spatially. Elephants (Loxodonta africana), are known to have extensive impacts on plant communities, altering ecosystem functioning and causing a decline in biodiversity. In enclosed areas, these impacts are increased leading to a decline in resource availability and presumably resource quality. In the Addo Elephant National Park, the Main Camp section has a history of high elephant impacts and therefore reduced resource availability. Whereas, the recently added Colchester section has greater resource availability, due to the absence of elephants in this section since the fencing of the Park. This study investigated the changes in diet (diet breadth, preference and diet quality) of elephants due to an increase in resource availability. Three alternative hypotheses were contrasted: 1) elephants as generalist foragers, 2) elephants as optimal foragers, or 3) elephants learning foraging behaviour. Using microhistological analysis, the diets of elephants were described over five sampling periods (August 2010 – February 2014) in both sections. Forage availability was estimated using a modified line-intercept method, and was used to determine changes in preference by relating forage availability to use. In the Colchester section the diet breadth of elephants increased, and was coupled with a high initial variation between the diets of elephants, which decreased in subsequent sampling periods. This supported the elephants learning foraging behaviour hypothesis. However, there was no increase in diet preference by elephants in the Colchester section, which supported the elephants as generalist foragers hypothesis. There was also no difference in the diet quality of elephants in the Main Camp and Colchester sections, which did not support any of the three hypotheses. The elephants learning foraging behaviour hypothesis is proposed to be the link between the alternate two hypotheses, and given enough time, either of the two could be supported. The lack of difference in preference and diet quality between elephants in the Main Camp and Colchester sections is hypothesised to be due to the population level (not measured for individuals) at which these were measured. Microhistological analysis of faeces was used to describe the diet of elephants, which was compared to the diet described by DNA metabarcoding. Microhistological analysis is a traditional, favoured technique used in describing the diet of wild herbivores, whereas DNA metabarcoding is a relatively new and untested technique. These two techniques have not yet been compared in the diet of megaherbivores. Results indicated that microhistological analysis identified significantly more grass in the diet of elephants, than DNA metabarcoding did, which was expected as previous studies also found overestimation of grasses. Microhistological analysis identified more plant families in the diet of elephants, than DNA metabarcoding. Most of the differences between the two techniques can be attributed to the difference in taxonomic resolution, which was due to the lack of a complete reference collection for DNA metabarcoding. Although either of the two techniques can be used to describe the diet of elephants, the most reliable results would be obtained when using both techniques. The findings of this study suggest that due to the high initial variation between the diets of elephants, with an increase in resource availability, the impacts will also initially be highly varied. This suggests that identifying plant species to monitor elephants impacts initially will be difficult. However, important plant species, or those known to be vulnerable to elephants impacts should be carefully monitored initially and monitoring should not only occur annually, but also seasonally.
424

Adaptation choices, community perceptions, livelihood linkages and income dynamics for district producer communities surrounding Nyatana Game Park in Zimbabwe

Taruvinga, Amon January 2011 (has links)
This thesis explores human-wildlife interactions under community managed game parks. The thesis consists of an introductory chapter, study location chapter and four self-contained studies based on different samples from created clusters surrounding Nyatana Game Park, which make up the rest of the thesis chapters. Chapter one presents an introductory overview of wildlife management in Zimbabwe, specifically looking at human-wildlife interactions under CAMPFIRE projects, welfare dynamics and conservation implications for the surrounding communities who share boundaries with community-managed game parks. The chapter concludes by highlighting the challenges facing community-based wildlife conservation in Zimbabwe as well as the key concepts that will be the subject of the rest of the thesis. Chapter two presents the study location; it highlights the road map to the study area, starting with the provincial location, and indicates the specific districts from which respondents were selected. A brief agro-ecological summary of the study area is also presented; it looks specifically at climate, vegetation and a demographic data of the study area. Chapter three: Can game parks be trusted as livelihood sources? To answer this topical question, Chapter three explores livelihood adaptation strategies for households who share boundaries with Nyatana Game Park. Most of the community managed game parks, under CAMPFIRE principles in Zimbabwe, were established with the primary objective of generating revenue for the surrounding communities; this was done in the hope of using positive returns from game farming to promote the conservation of wildlife. Has this materialised in practice? Descriptive results from this study seem to suggest otherwise, where mixed farming and gold panning were the major livelihood adaptation choices reported by most households. The revenue from game farming was reported to be too low and inconsistent, to such an extent that the majority of the community regarded it as risky and unreliable. A multinomial logistic regression model for correlates of adaptation choices indicated that access to credit, markets, and extension may be some of the current institutional constraints inhibiting households from accessing off-farm sources for their livelihoods. In addition, household size, gender and age may enhance the adaptive capacity of households to move out of risky crop faming into other off-farm portfolio diversifications. The study, therefore, suggests that game parks, according to the evidence uncovered by the study, may not be trusted as a reliable and sustainable livelihood source. If local communities who share boundaries with game parks do not view them as reliable and sustainable livelihood sources, as concluded in Chapter three, how can they (local communities) be trusted to conserve them? To assess their perceptions of game parks, Chapter four presents a multinomial logistic regression model for perceptions of society on game parks using the African elephant as a typical example. The results suggest that Problem Animal Control (PAC) perceptions, livestock predation and issues of low and poor revenue distribution may be some of the critical perceptions capable of influencing surrounding communities to negatively participate in the conservation of wildlife. The results further suggest that using wildlife proceeds to finance observable local common pool infrastructure may positively influence the surrounding communities to conserve wildlife. The chief conclusion regarding game parks, therefore, was that the surrounding communities were in favour of the obliteration pathway, although minimal conservation perceptions were also available. Given the negative conclusions regarding game parks, as suggested in Chapters three and four, citizens would then wonder if any meaningful hope for community managed game parks exists. Chapter five probes the buffer zone livelihood link under community managed game parks, using evidence from the Nyatana Game Park. The binary logistic regression model results, for buffer zone participation and resource extraction combinations by surrounding communities, suggest that resource extraction may be market driven rather than focussing on domestic consumption. The study therefore concludes that the buffer zone livelihood link as currently practiced, though potential, may fail to address the livelihood expectations of the sub-district producer communities. The study therefore calls for extreme caution whenever the buffer zone livelihood link is considered, because several institutional and design conflicts exist within this dynamic. In Chapter six, the study further probed the buffer zone income dynamics for the sub-district producer community. The results of descriptive statistics suggest that the contribution of buffer zone activities to household income may be significant with a positive correlation to household agricultural income for communities who reside inside or close to the park (primary sub-district producer community). Using the Gini decomposition approach and Lorenz curves, the study concluded that a buffer zone income may be capable of contributing to more equally distributed incomes for rural communities who share boundaries with game parks. With respect to the correlates of household income, the results suggest that household size and age may negatively influence income from buffer zone activities, while gender may have a positive effect. This was also true for education and Livestock Units (LUs) with respect to income from self employment; the former positively and the latter negatively related. The results further suggest that land size may also be positively significant in order to explain income from agriculture as well as total income. With regard to the distance from the buffer zone, the results suggest a negative influence with respect to the buffer zone, agriculture and total income. The implied message therefore suggests that buffer zones may provide active livelihood sources which are capable of financing rural household agriculture. The income equalizing effect which is portrayed may also further imply that, if correctly targeted and promoted, a buffer zone income could possibly address the current income inequality which is generic in rural areas. However, this potential may not be realized due to the current buffer zone design status (created for local secondary use as opposed to commercial primary use), restrictive policies and poor institutional support. With this dilemma facing community managed game parks (threats as summarised in Chapters three and four amid the potential hope summarized in Chapters five and six), Chapter 7 concludes the study by suggesting that the human-wildlife interaction model, though currently theoretical, may have significant practical potential in addressing the livelihoods of the surrounding communities as well as promoting the conservation of wildlife. This could be possible if available challenges that range from low revenue, insecure property rights, high human-elephant conflict and institutional design conflict for buffer zone utilization are corrected by means of the free market system. This would allow market forces to deliver on the expectations of the ―human-wildlife interactions model‖ – sustainable livelihoods for the former and intergenerational conservation for the latter.
425

Managing forests and understanding social intolerance for Ohio’s declining timber rattlesnakes

Hoffman, Andrew Stewart 07 October 2021 (has links)
No description available.
426

Black Vulture (Coragyps atratus) Range Expansion: An Example of Human Wildlife Conflict

Latteman, Holly M. 23 September 2019 (has links)
No description available.
427

Changing the Stories We Live By: Revolutionizing the North American Model of Wildlife Conservation Through Transformative Conservation

Burroughs, Tess Marie January 2022 (has links)
As biodiversity continues to diminish worldwide, an interrogation of long-standing conservation discourse is needed to reformulate a new conservation rhetoric that confronts the socio-ecological complexities of the world and reorients the relationship between humans and nature. Using ecologically sensitive critical discourse analysis, this research investigates the dominant ideologies perpetuated within an iteration of mainstream American wildlife discourse and explores opportunities for transformative conservation alternatives. Critical discourse analysis is performed on the State Wildlife Action Plans policy framework, which serve as the United States’ primary comprehensive wildlife conservation strategies that guide states in the preservation of fish and wildlife. Analysis of the State Wildlife Action Plans Report and Best Practices for State Wildlife Action Plans documentation revealed three dominant ideologies constructed and perpetuated within this conservation program, summarized as “Human Centrality,” “Animals as Resources,” and “The Supremacy of the Economic.” These three ideologies are manifestations of the overarching worldview of Anthropocentrism. After identifying the potentially harmful impacts associated with these ideologies, new stories inspired by insight from various environmental philosophies, Indigenous beliefs, and historical conservation leaders that align with the tenets of transformative conservation are created. These three new, alternative stories are: “Honoring the Intrinsic Value of Nature,” “Humans and Nature Rejoined,” and “Decentering the Economic.” By disentangling the hegemonic ideologies and power relations upheld within American conservation discourse, novel ways of thinking inspired by transformative conservation can be forged to combat biodiversity loss.
428

Developing monitoring protocols for North American beavers (Castor canadensis) in Ohio

Kenyon, Madeline 04 May 2022 (has links)
No description available.
429

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.
430

Blubber transcriptome and proteome responses to repeated adrenocorticotropic hormone administration in a marine mammal

Deyarmin, Jared 01 January 2019 (has links)
Chronic physiological stress impacts animal fitness by catabolizing metabolic stores and suppressing reproduction and immunity. This can be especially deleterious for capital breeding carnivores, such as marine mammals, which rely on lipid stores accrued during intensive foraging to sustain prolonged periods of fasting associated with reproduction. Therefore, chronic stress may cause a decrease in fitness in these animals, leading to population declines and potentially detrimental shifts in food web dynamics as a result. However, the impacts and indicators of chronic stress in animals are currently poorly understood. To identify downstream mediators of repeated stress responses in marine mammals, adrenocorticotropic hormone (ACTH) was administered once daily for four days to free-ranging juvenile northern elephant seals (Mirounga angustirostris) to stimulate endogenous corticosteroid release. I then compared blubber tissue transcriptome responses to the first and fourth ACTH administrations to determine the effects of acute and chronic endocrine stress, respectively. Gene expression profiles showed differences in responses to single and repeated ACTH administration, despite similarities in circulating cortisol profiles. We identified 61 and 12 differentially expressed genes (DEGs) in response to the first ACTH and fourth administrations, respectively, 24 DEGs between the first and fourth pre-ACTH samples, and 12 DEGs between ACTH response samples from the first and fourth days. Annotated DEGs were associated with functions in redox and lipid homeostasis, suggesting potential negative impacts of repeated stress on marine mammals. In addition, protein expression profiles were discrete between single and repeated ACTH administrations, and identified changes in expression of extracellular proteins that were not detected at the transcriptome level. We identified 8 and 7 differentially expressed proteins (DEPs) in response to the first and fourth ACTH administrations, respectively, including 5 DEPs in the overall ACTH response, 1 DEP between the first and fourth pre-ACTH samples, and 10 DEPs between ACTH response samples from the first and fourth days. Differentially expressed proteins in response to repeated ACTH administrations were associated with extracellular matrix (ECM) remodeling and suggest a link between glucocorticoid-induced adipogenesis and ECM remodeling in blubber. Other differentially expressed proteins were associated with increased lipid metabolism and decreased immunity, consistent with transcriptome data. Together, the use of transcriptomics and proteomics to detect responses to repeated stress provides more comprehensive insight into the marine mammal stress response and highlights the importance of using multiple discovery-driven approaches for understanding stress physiology. The gene and protein markers identified in this study may be used to identify stressed animals and discriminate between acutely and chronically stressed individuals with higher sensitivity than hormone measurements alone.

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