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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

Bog Turtle (Glyptemys muhlenbergii) Population Dynamics and Response to Habitat Management in Massachusetts

Vineyard, Julia 14 November 2023 (has links) (PDF)
The Bog Turtle (Glyptemys muhlenbergii) is a federally threatened species that occupies isolated pockets of open-canopy fens. This long-lived species is susceptible to habitat loss and degradation; thus, the conservation of known populations and management of their habitat is critical to the species’ survival. Long-term (multi-decadal) assessment is important for determining population trends and responses to ongoing habitat management. I assessed population demographics (abundance, survival) and spatial distribution (home range) of two Bog Turtle populations in Massachusetts that have been managed since the late 1990s by treating invasive species, thinning woody vegetation, and mitigating flooding. The results of this study were compared to two previous studies conducted in 1994–1997 and 2005–2009 to evaluate the response to habitat management. Estimates of adult population abundance increased from the first study period (Site 1 X̅= 37.3 ± 10.4, Site 2 X̅= 36.2 ± 3.2) to the last study period (Site 1 X̅= 65.1 ± 17.9, Site 2 X̅= 42.5 ± 10.9) across both sites. Estimates of annual survival across all study periods remained above 90% at Site 1 and were 100% for two years at Site 2. I constructed 95% minimum convex polygon (MCP) and 95% kernel density estimation (KDE) home ranges for 71 turtles. At Site 1 there was no significant influence of the study period on home range estimates. The increase in abundance estimates, high survival, and stable home range sizes at Site 1 suggest that ongoing management has maintained quality habitat. At Site 2, the average home range size decreased by approximately half after the first study period in response to flooding but increased in the current study. Fluctuations in population abundance, and home range size at Site 2 throughout the study period reflect the cycles of habitat degradation and habitat management. My results indicate that habitat management efforts implemented since the late 1990s have provided quality habitat for the two Bog Turtle populations in Massachusetts while also mitigating long-term negative impacts on the populations. This further supports the need for long-term analysis of Bog Turtle populations, especially at sites where active habitat management is occurring.
12

Human Dimensions of Young Forest Conservation Programs: Effects of Outreach, Post-Program Management, and a Coupled Systems Perspective

Lutter, Seth Hendrik 13 August 2018 (has links)
Achieving long-term conservation gains through the framework of conservation incentive programs requires an understanding of both the ecological and social components of these programs. Landowner program experiences and management decisions after program participation are important for long-term conservation, but these aspects of conservation programs are not well understood. To address this research gap related to conservation program participation, this thesis investigates Natural Resources Conservation Service programs that provide private landowners with financial and technical assistance to manage for young forest habitat in the eastern United States. We conducted a telephone survey to investigate private landowner experiences during and after participation in these NRCS conservation programs. Coordinating with biologists monitoring managed properties for birds, we assessed how in-person outreach and mailed monitoring results influenced landowners. Next, we evaluated how landowner motivations, resources, and cognitions were related to post-program young forest management intentions. Finally, we applied a coupled human and natural systems lens to investigate the linkage between wildlife outcomes, landowner perceptions, and continued young forest management. Our results demonstrate how in-person outreach can shape positive conservation experiences and increasing landowner trust in resource agencies. We also demonstrate the importance of both social and environmental factors for influencing landowner decision-making after conservation program participation. We detail the applications of this research for conservation agencies and professionals who work with private landowners. / Master of Science / The decline of young forest habitat and associated wildlife species is a major conservation issue in the eastern United States. Since 2011, Natural Resources Conservation Service conservation programs have provided hundreds of private landowners with financial and technical assistance to create and maintain young forest habitat. Landowner program experiences and management decisions after program participation are important for long-term conservation, but information is limited on these aspects of NRCS young forest programs. In response, we conducted a telephone survey to investigate private landowner experiences during and after participation in these conservation programs. Coordinating with biologists monitoring managed properties for birds, we assessed how in-person outreach and mailed monitoring results influenced landowners. Next, we evaluated how landowner motivations, resources, and cognitions were related to post-program young forest management intentions. Finally, we examined how landowners observed and interpreted wildlife outcomes of young forest management and how these perceptions were related to habitat management after program participation. Our results highlight the importance of in-person outreach for shaping positive conservation experiences and increasing landowner trust in resource agencies. We also demonstrate the importance of both social and environmental factors for influencing landowner decision-making after conservation program participation. We detail the applications of this research for conservation agencies and professionals who work with private landowners.
13

Ecology and conservation of the butterfly Thestor brachycerus brachycerus (Trimen, 1883) from the Western Cape / Elizabeth Ann Bazin

Bazin, Elizabeth Ann January 2015 (has links)
The 1883 discovery, research into generic life histories and taxonomic investigations into the aphytophagous butterfly Thestor brachycerus brachycerus (the Knysna Skolly) from Knysna, South Africa are described. Its slide towards extinction through loss and degradation of habitat in the late 20th century left only one known colony by 2009 leading to it being assessed as Critically Endangered in the 2013 South African Red List and Atlas. During searches for more populations in 2011, a second T. b. brachycerus colony was found which differed markedly with respect to aspect, altitude and vegetation. Study areas were defined around the original colony on the Pezula Golf Estate (Pezula) and the newly discovered coastal colony east of Coney Glen (Coastal site). An assessment is made of the ecological differences and similarities between the two sites. The extent and size of the two known populations was measured; the Extent of Occupancy was found to be 7.5 km2 and the Area of Occupancy as 1.05 x 10-3 km2. During observations over 5 seasons in December and January 2009 – 2014 the average number of butterflies observed at the original Pezula colony varied from 1 – 8 males and 0 – 3 females per survey, compared with 1 – 6 males and 1 – 3 females observed over 3 seasons from 2011 to 2014 at the Coastal colony. The mating, territoriality, oviposition and predation avoidance behaviour of the adult T. b. brachycerus butterflies was studied by direct observation. Males were found to exhibit territorial behaviour, spending long periods of time perched in one spot, particularly in areas where the vegetation was open or low. Oviposition was rapid and no preference was shown by females for any particular plant. Between the two colonies, oviposition was observed on a total of 16 different plants. The vegetation composition at the two study sites was analysed using Braun–Blanquet methodology. Only one plant, Tarchonanthus littoralis, was found to be common to both. There appeared to be no correlation between floristic composition and the occurrence of T. b. brachycerus. All the Thestor species so far studied by other workers have been found to be myrmecophilous, having an association with the pugnacious ant Anoplolepis custodiens. Ant communities were sampled by employing pitfall traps and direct sampling by hand. At both the Pezula and Coastal sites A. custodiens was the most ubiquitous ant species. The insights gained have enabled implementation of a habitat management plan. Experimental management methods are recommended at the Pezula site which include small scale burning and selective cutting of vegetation. Search for more colonies is ongoing, using the improved ecological knowledge of the butterfly. / MSc (Environmental Sciences), North-West University, Potchefstroom Campus, 2015
14

Ecology and conservation of the butterfly Thestor brachycerus brachycerus (Trimen, 1883) from the Western Cape / Elizabeth Ann Bazin

Bazin, Elizabeth Ann January 2015 (has links)
The 1883 discovery, research into generic life histories and taxonomic investigations into the aphytophagous butterfly Thestor brachycerus brachycerus (the Knysna Skolly) from Knysna, South Africa are described. Its slide towards extinction through loss and degradation of habitat in the late 20th century left only one known colony by 2009 leading to it being assessed as Critically Endangered in the 2013 South African Red List and Atlas. During searches for more populations in 2011, a second T. b. brachycerus colony was found which differed markedly with respect to aspect, altitude and vegetation. Study areas were defined around the original colony on the Pezula Golf Estate (Pezula) and the newly discovered coastal colony east of Coney Glen (Coastal site). An assessment is made of the ecological differences and similarities between the two sites. The extent and size of the two known populations was measured; the Extent of Occupancy was found to be 7.5 km2 and the Area of Occupancy as 1.05 x 10-3 km2. During observations over 5 seasons in December and January 2009 – 2014 the average number of butterflies observed at the original Pezula colony varied from 1 – 8 males and 0 – 3 females per survey, compared with 1 – 6 males and 1 – 3 females observed over 3 seasons from 2011 to 2014 at the Coastal colony. The mating, territoriality, oviposition and predation avoidance behaviour of the adult T. b. brachycerus butterflies was studied by direct observation. Males were found to exhibit territorial behaviour, spending long periods of time perched in one spot, particularly in areas where the vegetation was open or low. Oviposition was rapid and no preference was shown by females for any particular plant. Between the two colonies, oviposition was observed on a total of 16 different plants. The vegetation composition at the two study sites was analysed using Braun–Blanquet methodology. Only one plant, Tarchonanthus littoralis, was found to be common to both. There appeared to be no correlation between floristic composition and the occurrence of T. b. brachycerus. All the Thestor species so far studied by other workers have been found to be myrmecophilous, having an association with the pugnacious ant Anoplolepis custodiens. Ant communities were sampled by employing pitfall traps and direct sampling by hand. At both the Pezula and Coastal sites A. custodiens was the most ubiquitous ant species. The insights gained have enabled implementation of a habitat management plan. Experimental management methods are recommended at the Pezula site which include small scale burning and selective cutting of vegetation. Search for more colonies is ongoing, using the improved ecological knowledge of the butterfly. / MSc (Environmental Sciences), North-West University, Potchefstroom Campus, 2015
15

Sagebrush Ecology of Parker Mountain, Utah

Dulfon, Nathan E. 01 May 2016 (has links)
Parker Mountain, is located in south central Utah, it consists of 153 780 ha of high elevation rangelands dominated by black sagebrush (Artemisia nova A. Nelson), and mountain big sagebrush (Artemisia tridentata Nutt. subsp. vaseyana [Rybd.] Beetle) communities. Sagebrush obligate species including greater sage-grouse (Centrocercus urophasianus) depend on these vegetation communities throughout the year. Parker Mountain is owned and managed by Utah School and Institutional Trust Lands Administration, Bureau of Land Management, and the United States Forest Service. Land management on Parker Mountain include wildlife conservation and providing sustainable ecosystem services such as livestock grazing. My research described the species composition of the black sagebrush communities, evaluated the long-term vegetation responses to two mechanical (Dixie harrow/Lawson aerator) and one chemical treatment (tebuthiuron), and herbaceous biomass responses to tebuthiuron treatments in mountain big sagebrush communities on Parker Mountain. My results indicated when black sagebrush canopy cover was <20%, average grass canopy cover was highest (13%). When black sagebrush canopy cover exceeded 40%, grass canopy cover was lowest (8%). Forb canopy cover was relatively consistent (5%) across black sagebrush communities with >20% canopy cover. Communities with <20% black sagebrush canopy cover had the lowest forb canopy cover. Tebuthiuron reduced mountain big sagebrush percent canopy cover (>9 years), increased grass canopy cover, and increased forb canopy cover more than the two mechanical brush control methods. Tebuthiuron treatments shifted sites from xeric to more mesic plant communities, which resulted in increased percent forb cover required by greater sage-grouse during late-brooding. Herbaceous biomass increased under tebuthiuron treatments in mountain big sagebrush pastures. Tebuthiuron treatments also reduced live sagebrush canopy cover for at least 9 years.
16

Effects of landscape configuration on northern bobwhite in southeastern Kansas

Flock, Brian E. January 1900 (has links)
Doctor of Philosophy / Department of Biology / Philip S. Gipson / Northern bobwhite (Colinus virginianus) populations in much of the species range have been declining for the last 35 years. I trapped and equipped bobwhite with radio transmitters and tracked them during 2003-2005. I used these data to examine the effects of landscape configuration on survival as well as the habitat association of bobwhite in southeastern Kansas. I used the nest survival model in Program MARK to determine the effects of habitat configuration on weekly survival of radio equipped bobwhite during the Fall-Spring (1 October to 14 April) and the Spring-Fall (15 April to 30 September) at home range and 500 m buffer scales. Individual survival probability for the Fall-Spring period was 0.9439 (S.E. = 0.0071), and the most parsimonious model for the Fall-Spring period at the home range scale was B0 + percent woodland + percent cropland. At the 500 m buffer scale the most parsimonious model was B0 + percent Conservation Reserve (CRP) program land. The weekly survival probability for the Spring-Fall period was 0.9559 (S.E. = 0.0098). At the home range and 500 m buffer scales there were weak associations of habitat to survival during Spring-Fall with the most parsimonious model for both scales B0 + percent other. Using Euclidean Distances to measure distance from animal location to each habitat, I found that habitat selection was occurring during the Spring-Fall (Wilkes λ = 0.04, F 6,36 = 143.682, P < 0.001) and Fall-Spring (Wilkes λ = 0.056, F 6, 29 = 81.99, P < 0.001). During Spring-Fall bobwhite were associated with locations near cool-season grasses and during Fall-Spring preferred locations near woody cover. Bobwhite also showed habitat selection at a second more refined land use classification level for Spring-Fall (Wilkes λ = 0.006, F 16, 26 = 284.483, P < 0.001) and Fall-Spring (Wilkes λ = 0.004, F 16, 19 = 276.037, P < 0.001). During the Spring-Fall, bobwhites were associated with locations near cool-season grass pastures and roads and during Fall-Spring were associated with locations in close proximity to roads and CRP. Understanding the effects of habitat configuration on bobwhite is an important step in developing a broad-scale management plan.
17

Understanding Human Disturbance to Birds at the Intersection of Birding and Bird Photography

Brennan G Radulski (9749159) 15 December 2020 (has links)
<div>Human disturbance to birds is a subject of concern for bird conservation. Bird recreationalists, such as birders and bird photographers, who actively seek out birds, are identified as a broad group of people that contribute to bird disturbance. There are few studies on birders’ and bird photographers’ perceptions and behaviors related to bird disturbance, and these studies have conflicting results. Furthermore, little research identifies why bird recreationalists engage in behavior that disturbs birds. Understanding perceptions and behavior related to bird disturbance and the context behind engaging in this behavior is important for creating comprehensive solutions for preventing disturbance to birds. The purpose of this thesis is to create a typology of bird recreationalists, based on whether they engage in birding or bird photography as primary activities; identify the socio-demographic characteristics among bird recreationalists that are connected to an increased likelihood to engage in behavior that disturbs birds; assess perceptions of blame for disturbance to birds; and identify how motivations, barriers, challenges and trade-offs are associated with following ethical birding and bird photography guidelines. </div><div><br></div><div>The thesis used an online survey and in-person interviews of birders and bird photographers in two Midwestern states in the U.S., Illinois and Indiana, to achieve these objectives. Three sub-groups of bird recreationalists were identified through the online survey: individuals who only engage in birding; individuals who primarily engage in birding and secondarily, bird photography; and individuals who primarily engage in bird photography and secondarily, birding. Our findings indicate that individuals who 1) are male, 2) only engage in birding, 3) maintain life lists, 4) have more birds on their life lists, 5) can identify more birds by sight, 6) have more years of experience or 7) have a higher level of achievement-oriented motivation are more likely to engage in potentially harmful behaviors to birds. Additionally, quantitative findings suggest that birders and bird photographers may not perceive themselves as main contributors to bird disturbance. </div><div><br></div><div>The qualitative portion of the research identifies multiple ethical birding and bird photography guidelines that recreationalists found challenging to follow that had both ecological (e.g., maintaining distance) and social (e.g., respectfully educating others) implications. Recreationalists identified listing, photographing and seeing birds as key motivations to breaking ethical guidelines. Barriers to following guidelines included apathy, ignorance and improper technology. Finally, recreationalists identified bad photography and missed experiences as major trade-offs associated with following ethical guidelines. he concepts explored in this thesis research provide important management implications for natural resource managers and stakeholders in bird conservation and suggest a further need for examining bird recreationalists’ decision-making around bird disturbance.</div>
18

Habitat Associations Between the Northern Flying Squirrel and Red Spruce

Ashley L Archer (9191999) 31 July 2020 (has links)
<p>Red spruce forests, one of the most critically endangered ecosystems in the United States</p>provides critical habitat for several endemic species or subspecies of the Appalachian Mountains, including the Virginia northern flying squirrel. Once listed as threatened under the Endangered Species Act, the Virginia northern flying squirrel was delisted in 2013. Managers are currently focusing their efforts on projects that increase the extent and connectivity of the squirrel’s habitat through red spruce restoration. At present, there is a paucity of available data to assess the implications of the silvicultural activities associated with red spruce restoration on the movement and occupancy of the Virginia northern flying squirrel. In order to inform management activities, I measured home range, fine-scale habitat use, and estimated detection and occupancy for northern flying squirrels across a gradient of red spruce stands in the Monongahela National Forest. I concluded that home ranges for northern flying squirrels within this region are comprised primarily of red spruce and that northern flying squirrels were selecting larger diameter trees compared to the nearest available neighbor. Additionally, I found that microhabitat characteristics alone did not sufficiently predict northern flying squirrel occupancy and that acoustic methods for surveying northern flying squirrels will require further refinement. Future research efforts should focus on a combination of landscape-level and microhabitat covariates to best predict occupancy of this species across the landscape. Future red spruce management should be approached with caution regarding the potential impact on northern flying squirrel habitat in the short-term. I recommended using spatially-explicit modeling to assess the long-term effects of proposed red spruce restoration projects on northern flying squirrel population demographics, dispersal, and metapopulation connectivity prior to the implementation of silvicultural treatments.
19

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.
20

Ecology of Yellow Rail (Coturnicops Noveboracensis) Overwintering in Coastal Pine Savannas of the Northern Gulf of Mexico

Morris, Kelly Marie 14 August 2015 (has links)
The Yellow Rail (Coturnicops noveboracensis) is a migratory nongame bird of high conservation priority throughout its entire range. The objectives of this study were: (1) assess Yellow Rail occupancy in the context of prescribed fire regime in pine savanna habitats of Mississippi and Alabama and (2) assess Yellow Rail habitat use in pine savanna habitats of coastal Mississippi. Yellow Rail occupancy decreased significantly with time since fire and increased with grassland patch size. Throughout the study area Yellow Rail maintained small (mean = 3.37 ha) home ranges aggregated within study areas, indicating suitable habitat may be limited. Yellow Rail used areas dominated by Aristida stricta and Carex spp. They used locations with lower woody percent cover, greater herbaceous height structure and lower frequency of trees than locations outside their home range. This research highlights the continued need to prioritize conservation and management of open grasslands and pine savanna habitats.

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