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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.
101

Summer Home Range Fidelity in Adult Female Elk (Cervus elaphus) in Northwestern Colorado

Brough, April M. 01 December 2009 (has links)
Understanding the degree of spatial fidelity of individuals within a species increases our ability to manage appropriately. Elk (Cervus elaphus) is a highly managed species in the Intermountain West, but there is little research evaluating summer home range fidelity of individual elk. We evaluated fidelity of 72 adult female elk to individual summer-fall home ranges in the White River study area in northwestern Colorado during two consecutive summers. Based on individual kernel-estimated utilization distributions, we used (1) the Volume of Intersection (VI) statistic and (2) interannual distances between centers of mass to compare summer range overlap and distribution. We also examined the role of landcover in summer habitat selection by elk from three distinct perspectives: landscape, individual, and philopatric. While many previous habitat studies included landscape analysis, few incorporate individual analysis and none contain a philopatric assessment, to our knowledge. We found adult female elk in the White River Study area exhibit fidelity to individual home ranges. VI values indicated that 93% of the elk showed some home range overlap, with a median value of 0.42 (SE = 0.02, n = 72). Between-year center-of-mass distances ranged from 183 m to 34,170 m (x = 3819, SE = 619, n = 72), while within-year maximum distances between location points ranged from 4,320 m to 31,680 m (x = 13,958, SE = 628, n = 72). Our landcover results indicated elk can be characterized as both generalists and specialists. While elk occurred across a very diverse landscape, we found a preference for Aspen-Mixed Conifer, Aspen, and Dry-Mesic Spruce-Fir landcover types, and a general avoidance of Agriculture, Sagebrush Steppe, Subalpine Meadow, and Grassland. We also found a high degree of similarity in landcover composition between years for individual elk. Elk home range fidelity could impact habitat management, specifically with respect to browsing and successful aspen (Populus tremuloides) regeneration. Incorporation of the philopatric perspective into future elk behavior and habitat selection studies could make results more rigorous and expand understanding of landscape-level results.
102

Examining the morphological and behavioral paradox of aye-ayes (Daubentonia madagascariensis) in Torotorofotsy, Madagascar

Sefczek, Timothy Mikhail January 2018 (has links)
No description available.
103

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.
104

Multi-Scale Spatial Selection of a Large Solitary Omnivore, American Black Bear

Gantchoff, Mariela Gisele 10 August 2018 (has links)
Movement of organisms is a fundamental component of many ecological processes, and should be subject to strong selective pressures. Spatial selection is the process by which individuals choose the locations to acquire necessary resources or avoid risk, and the relative importance of different factors on spatial selection may change depending on the scale being analyzed. Under the framework of optimality, an individual should attempt to structure their spatial selection economically to maximize fitness. I studied black bear (Ursus americanus) space use, habitat selection, and movement under the optimality paradigm in three populations (Michigan, Missouri, and Mississippi) at four different scales: regional, annual home range, seasonal home range, and denning sites. At the regional scale, I found that black bears displayed scale-dependent land cover selection for movement, selecting forested areas at coarser scales and avoiding anthropogenic disturbance at finer scales, and that large contiguous forests and riparian corridors most facilitate connectivity among protected areas. At the annual and seasonal home range scales, I found black bears display scale-dependent optimizing strategies. Individuals locating their annual ranges to maximize access to areas of high vegetation productivity, together with the high productivity of ranges of all sizes, suggests an energy maximizing strategy, while the negative relationship between range size and both fragmentation and forest proportion suggests area minimizing. More limiting factors act at larger scales, which suggests productivity is the strongest limiting factor and energy maximizing is the dominant strategy while plasticity allows for seasonal area minimizing. At the den site scale, I found that both female and male black bears appeared to minimize anthropogenic risk during denning; however female black bears have a flexible response to anthropogenic disturbance, attempting to minimize it when alone or with older offspring, yet having increased tolerance when infanticide is greater after cubs are born and following den emergence. By quantifying black bear space use and selection across multiple scales, diverse areas, over time, and among and within individuals, I revealed consistent scale-dependent responses to environmental and biological factors while highlighting the intrinsic plasticity of this flexible omnivore.
105

Spatial Ecology of Eastern Coyotes (Canis latrans) in the Anthropogenic Landscape of Cape Cod, Massachusetts

Page, Maili 01 January 2010 (has links) (PDF)
Historically, coyotes were associated with the western United States. During their expansion eastward, coyotes have become more tolerant of humans and have been able to live in varying degrees of urbanization. One main question ecologists around the country are asking is how coyotes are surviving in anthropogenic environments. To aid in answering this question, I have compared coyote land use preference generally and specifically during coyote breeding season, winter and summer, human tourist seasons, and day and night. I also compared coyote land cover preference for deciduous and evergreen cover types during natural seasons. I found that, in general, there was a high variation of preference between and within land use categories. More broadly however, they prefer natural areas over non-natural areas. They used natural and non-natural land use types equally in winter and summer, and during tourist and off-tourist seasons with increased variation in preference during seasons with higher human activity. They had a higher preference for non-natural land use types at night. There is no difference in coyote preference for deciduous or evergreen cover types during the seasons.
106

Home range- and behavioural analysis of the Saddleback tamarin (Leontocebus fuscicollis) in Madre de Dios, Peru

Nymark, Marianne Kristine January 2023 (has links)
60% of primates in the world are threatened with extinction, while 75% have declining populations. The biggest threats to primates are the result of human activity. In this study, I have been looking at the primate Spix’s Saddleback tamarin (Leontocebus fuscicollis) and tried to estimate the home range size of four different study groups, while also trying to assess if there are differences in the type of trees in the areas where the tamarins are present compared to where they are absent. I have also compared the behaviour of the four different study groups. The data was collected in the Tambopata nature reserve in the Madre de Dios region in Peru during the summer of 2022, with the help and support from the research organisation Fauna Forever. To complement the observations, previously collected data from 2019-2021 was also used. The tamarins were followed using a group follow method, and the behaviour was noted every 10 minutes using an instantaneous scan sampling method. The tree composition data was gathered from previously created tree plots, made by the Fauna Forever staff. I found that the home range sizes of the four study groups varied between 2.6 ha and 17.9 ha. The data from the tree plots showed no statistically significant difference in where the tamarins chose to live. There was also no statistically significant difference between the four study groups in behaviour, except for how high up in the trees they groups spent their time. There was a lack of good data in this study, due to time- and material constraints, but overall the home ranges were of close to similar size as earlier studies, and the behaviour of the tamarins was in general also consistent with earlier studies. More research would be needed to answer the further questions that arose during this study concerning the ecological constraints of the tamarins home range.
107

Spatial Ecology, Population Structure, and Conservation of the Wood Turtle, Glyptemys Insculpta, in Central New England

Jones, Michael T. 01 May 2009 (has links)
Abstract (Summary) Wood turtles ( Glyptemys insculpta ) are of conservation interest rangewide. Anecdotal accounts demonstrate that some populations have been decimated since 1850, and recent studies demonstrate that declines are still underway. From 2004-2008 I investigated the ecology of wood turtles in Massachusetts and New Hampshire. I obtained between one and five years of annual home range data for 150 turtles, and evaluated population structure at 31 sites in five major watersheds. Seasonal floods displaced 7% of wood turtles annually in one watershed, and accounted for elevated mortality. Twelve wood turtles were displaced < 16.8 km, and two were displaced over a 65-foot dam. Several turtles overwintered at their displacement site and two returned successfully, indicating that floods are a mechanism of population connectivity. Several homing turtles ended up in new areas. Turtles occupied stream segments with gradient < 1%, lower than generally available. Agricultural machinery accounted for most observed mortality, followed by automobiles and mammals. Female turtles exhibit smaller home ranges in agricultural areas. Older turtles move farther from the river than do young turtles, possibly reflecting their familiarity with a former landscape. Population density ranged from 0-40.4 turtles/river-kilometer. The highest densities occur in central New Hampshire and lower densities occur in the Housatonic watershed. Population density is negatively correlated with agriculture at both riparian and watershed scales, and responds unimodally to forest cover. Wood turtle populations in western Massachusetts are declining by 6.6-11.2% annually. I estimated ages of turtles by assessing shell-wear rates from photographs. Wood turtles regularly achieve ages over 80 years, and like related species, do not exhibit clear signs of senescence. Old wood turtles are reproductively dominant, and their survival rates are twice as high as young turtles. Carapace scutes appear to require 80 years to become worn. Population modeling indicates that wood turtle populations are declining in New England due to anthropogenic and natural factors. Conservation efforts must address the effects of agriculture on adult survival. Climate change may negatively affect northeastern wood turtles through increased flooding. Populations in mountainous areas may be likely candidates for conservation because they don't occupy prime agricultural land, but may be more susceptible to floods.
108

Ecology and Conservation of Sumatran Elephants (Elephas maximus sumatranus) in Sumatra, Indonesia

Sitompul, Arnold Feliciano 01 February 2011 (has links)
Sumatran elephant (Elephas maximus sumatranus) populations continue to decline due to habitat loss, poaching and conflict with humans. In Sumatra, elephant populations are fragmented into small isolated populations and increasingly cause conflict with humans. Yet, habitat loss due to the rapid land conversion for development is continuing an alarming situation. Developing effective land conservation strategies for elephants is difficult because there is little information available on foraging ecology, habitat use, movements and home range behaviors. I conducted a study on these topics in Seblat, Bengkulu Province, Sumatra during 2007-2008. The five important families of plants in the elephant diet in Sumatra ar: Moraceae, Arecaceae, Fabaceae, Poaceae,and Euphorbiacea. Elephants in Seblat tend to browse more than graze and elephants tend to browse more during the wet season. The nutritional quality (Crude Protein, Calcium, Phosphorus and Gross Energy) of elephant diet in Seblat is suitable to support population reproduction and growth. Home range size of one telemetered 97.4 km2 for the MCP and 95.0 km2 for the 95% fixed kernel. There was no relation between average monthly elephant home range sizes and rainfall, nor any correlation between monthly elephant movement distances and rainfall. Vegetation productivity, as measured by the Enhanced Vegetation Index (EVI), was probably the factor most affecting elephant movements compared to the distances to rivers and ex-logging roads on the SECC. Resource selection analyzes indicate that elephants in Seblat seem to select medium canopy and open canopy areas more than expected. Similarly, habitat ranking using compositional analysis shows that in 2nd order and 3rd order selection, medium canopy and open canopy were the two habitat types with a greater level of used. Habitat use based on diurnal and nocturnal elephant activities indicates that elephants preferred closed canopy habitat compare to the open canopy habitat during the day. The results of this study suggest wide conservation implications for elephants on Sumatra, helping to guide effective land use conservation programs and provide scientific guideline to restore disturbed habitat and select priority areas for Sumatran elephants.
109

Elephant space use in relation to ephemeral surface water availability in the eastern Okavango Panhandle, Botswana

Makati, Anastacia 03 July 2023 (has links) (PDF)
The movement and distribution of elephants can be influenced by environmental factors over time (Foley, 2002). Examining how features in the landscape such as vegetation productivity, water sources and anthropogenic activities drive the movement of elephants can help in understanding patterns of movement. It can also help to inform the establishment and alignment of protected areas, wildlife corridors and identification of tourism hotspots as well as policy interventions to manage Human-Elephant Conflict (HEC). The Okavango Panhandle in Botswana is a HEC hotspot and the focus of My study. A number of strategies to address HEC are underway in the area, however one longer term strategy that has been proposed in this area involves provision of artificial water sources to influence elephant movements and keep animals away from fields during the cropping season. However, an improved understanding of how elephants utilize their habitats in relation to natural ephemeral surface water and other factors that influence their movements from dryland habitats to the Okavango Delta resources is needed to inform such management decisions. My study seeks to establish the role of ephemeral surface water on elephant distribution in the eastern Okavango Panhandle, Botswana as well as assess the movement distribution of elephants in relation to the seasonality, proximity and spatial extent of water presence represented by ephemeral surface water. Time series analysis of water extent on ephemeral surface water of the eastern Okavango panhandle will be developed and overlaid with elephant movement datasets. Elephant collar data from 15 elephants (5 males and 10 females) in the eastern Okavango Panhandle, Botswana have been analysed and Home Range (HR) sizes estimated using Kernel Density Estimation (KDE). The relative importance/probability of environmental variables in determining elephants' movement based on the Utilization Distribution (UD) were computed using Generalized Linear Mixed Models (GLMMs). I utilized a remote sensing spectral index, namely the Automated Water Extraction Index (AWEI) to delineate ephemeral surface water in dryland (excluding permanent waters) of the study area. The results reveal that during the wet season, elephants were evenly spread out all over the study area until the early dry season (April-June) when the ephemeral waterholes dried up. Elephants moved southwards towards the permanent waters of the Okavango River, where there are many human settlements and farms. Male HR sizes were found to be bigger than those of female elephants. Wet season (early and late) home range sizes were also bigger when compared to dry season (early and late) HR size. Mean daily distances were computed to investigate the effect of season on elephant daily distances and the distances ranged between 5km and 6.8km in the late wet and in the early wet and late dry season respectively. The Resource Selection Function (RSF) analysis shows that water adjacent sites are preferred over distant ones and both sexes prefer areas with high NDVI, with this preference being more pronounced in males. The seasonal variation of water use is notable in that it affirms the importance of proximity to water for elephants and has implications for their management and HEC. For example, I found that ephemeral surface water has a significant role in influencing elephant spatial use in the area, particularly during the early and late wet season. As ephemeral pans dried and NDVI (vegetation greenness) decreased, elephants started to move closer to the Okavango Delta and consequently human settlements and fields. However, further investigations into the timing of movements away from ephemeral waterholes and the influence of other environmental factors on elephant movements in the area would be needed before any recommendations can be made regarding artificial water provision in this area.
110

Response of male white-tailed deer (Odocoileus virginianus) to human activity on the landscape

Henderson, Colby 07 August 2020 (has links)
Human activity affects white-tailed deer (Odocoileus virginianus) movement and habitat selection during all times of the year, but knowledge is limited regarding how human risk affects white-tailed deer during the summer and winter. During spring and summer, variation in patch selection varied. Natural vegetation was selected for early in the year, with anthropogenic forages being important for deer use during the summer. During the winter, deer responded to different levels of risk. As hunter risk increased on the landscape, deer altered selection of the landscape. Deer avoided areas that were heavily used by hunters, using areas containing less hunter risk. Use of land cover classifications varied temporally, with cover selected for during the day and forage selected for at night. I have demonstrated that deer respond to human activity on the landscape, by selecting for anthropogenic foraging sources during the spring and summer and avoiding patches that contain risk.

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