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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.
31

The movement and landscape use of Blue Cranes in the Western Cape

Davis, Sydney Pierce 21 February 2019 (has links)
The Western Cape population of Blue Cranes (Anthropoides paradiseus) is the largest and most stable population for the species. The population is primarily threatened by high mortality due to collisions with power-lines and the development of wind farms. Yet, little is known about how this population uses the agricultural landscape and their movements. Thirteen Blue Cranes were fitted with trackers to collect Global Position System data and tracked for 3 – 18 months in the Overberg region of the Western Cape. With the provided spatial-temporal information, I estimated the home range size, daily flight distances, and distance travelled throughout the day of breeding and non-breeding cranes to determine whether the breeding status/season influences their ranging behaviour. There was no significant difference of the home range size between breeding cranes and non-breeding cranes (p > 0.05). There was also no significant difference of the home range size of breeding cranes between their seasons (p > 0.05). Breeding cranes travelled significantly shorter daily flight distances than non-breeding cranes (p < 0.05). Breeding cranes also travelled significantly shorter daily distances during the breeding season than the non-breeding season (p < 0.01). All cranes, regardless of breeding status or season, travelled further distances in the morning, decreasing distance during the midday and early afternoon with an increase in the late afternoon. Breeding cranes travelled shorter distances throughout the day than non-breeding cranes during the breeding season (p < 0.001). Lastly, breeding cranes travelled significantly shorter distances throughout the day in the breeding season than the non-breeding season (p < 0.001). From this study the results suggest that factors other than breeding status influence the ranging behaviour of these cranes. Factors such as the availability of roost and forage sites, the agricultural landscape of the Overberg and the presence of other Blue Cranes could also affect ranging behaviour. Although this study does not give clear guidelines on the movement of the population, it establishes a baseline for further studies into factors that affect their ranging behaviour and can still be used to aid in conservation strategies for the species. Future studies should focus on recording their time budgets, including overnight GPS fixes and assessing ranging behaviour over multiple years.
32

History, Status, and Resource Selection of the American Black Bear in Mississippi

Simek, Stephanie Lynn 14 December 2018 (has links)
Historically, black bears occurred throughout Mississippi but by 1932, <12 bears remained. Repatriation in neighboring states and conservation efforts in Mississippi have led to the recolonization of at least 2 subspecies (U. a. luteolus and U. a. americanus) of black bears in the state. I compiled available data to provide a synthesis of the history, current status, and management of black bears in Mississippi. Additionally, I used global positioning data collected from radio collared bears to determine the influence of distance to source population, cover type, distance to roads, distance to water, wetland reserve program areas, and human population density on black bear resource selection at various spatial scales. I studied characteristics of space use and resource selection of recolonizing bears in the Mississippi Alluvial Valley (Delta). I assessed the influence of environmental parameters at the female core annual home-range (using 50% kernel density estimator) and male and female seasonal and annual home-ranges (95% kernel density estimator). Distance to source population and distance to roads had significant influence at the core female home-range scale. I found a sex-based difference in annual and seasonal home-ranges. I also found that bears exhibited response to and selection for specific resources with an affinity toward hardwood stands, particularly young-aged hardwoods. My research illustrates the importance of analyzing resource selection at multiple scales to gain a full understanding of parameters that influence the recolonization of a bear population.
33

Hunting dynamics, condition estimates, and movements of black bears hunted with hounds in Virginia

Higgins, Kristine 01 September 1998 (has links)
Effort and success of Virginia's bear houndsmen were determined through field and mail surveys, and hunter diaries. The number of houndsmen per chase ranged from 5 to 12, hounds ranged from 6 to 11, and each chase lasted 2 to 6 hours. Second chases of the day lasted 2 to 3 hours and 3 to 10 hounds were used. Fifty-three to 74% of all first attempts resulted in a chase and 24% to 44% of these bears treed. A 2nd chase occurred in 11% to 96% of attempts and 9% to 50% of bears treed. Five to 17% of the 1st bears and 13% to 21% of 2nd bears were harvested. Field surveys found virtually no differences in hunting effort or success between seasons, study areas, and years. The hunter diary appears to be the most reliable means of sampling hunter effort and success. The applicability of Schroeder's physical condition estimate (PCR) was tested on data from Maine's black bear population. Bears exposed to poor hard mast had lower PCR's than bears exposed to good hard mast (P = 0.009). PCR and body weights of adult female black bears in Virginia exposed to hunting did not differ from those not hunted (P = 0.09). Annual adult female, adult male, and cub survival and reproductive rates in the hunted population were numerically similar to those in the non hunted populations. Five radio collared females were experimentally chased by hounds. The chases,on average, lasted 0.9 hours and 43% of bears treed. The average total home range for 3 of the bears was 17.8 km². The area used by 2 of the 3 bears pursued by hounds did not differ from their total home range (P 3 0.05) based on the MRPP test. The area covered by 3 of the 5 pursued bears was 5.6%, 11.8%, and 79.7% of their home range. / Master of Science
34

Survival, home range, movements, habitat use, and feeding habits of reintroduced river otters in Ohio

McDonald, Kenneth P. January 1989 (has links)
No description available.
35

Seasonal Home Range Sizes, Transboundary Movements and Conservation of Elephants in Northern Tanzania

Kikoti, Alfred P. 01 September 2009 (has links)
Although the unprotected lands of northern Tanzania support large numbers of elephants, and provide critical linkages for wildlife movements across the region, there is little information on the dispersal patterns of elephants in these unprotected lands. Our home range measures (100% MCP) of 21 elephants with satellite collars in four study regions were highly variable (191 to 3,698 km2). Home range sizes (95% fixed kernel) of bulls were typically larger than those of females, and wet season ranges were typically larger than dry season ranges. There were large differences in average home range sizes reflected varying strategies for obtaining food and water and avoiding humans. All eight radio-collared elephants (3 bulls, 5 females) in the West Kilimanjaro study region crossed the Tanzania-Kenya border, but typically elephants crossed more frequently in the wet than the dry season, and bulls crossed 47% more frequently than females. These extensive transboundary movements indicate that the elephant populations of West Kilimanjaro and Amboseli NP constitute a single transboundary population. Based upon 14,287 fixes from eight collared elephants, the vast majority of time was spent in unprotected ( x=91.5%) versus protected (x =8.5%) areas. Amboseli NP was visited by all eight elephants and was the protected area most utilized ( x=8%, range 2-24%). Based upon the movements of 15 GPS-collared elephants in northern Tanzania, we identified eight areas that we considered important for wildlife conservation corridors/linkages for elephants. Our conservation priorities for these corridors were based upon the levels of threats and conservation potential. Community interviews and hilltop surveys were used in two Maasai villages to determine the extent of wildlife conflict, community attitudes towards elephants, and if elephants were using a vegetation corridor to move between Tanzania and southern Kenya. Elephants were the most problematic wildlife species and were considered a nuisance. However, they believed they attracted tourists, and generally did not believe elephant numbers should be reduced. Based upon elephant conflict and use and the communities' need to maintain areas for cattle grazing and medicinal plant collection, the two communities established the first wildlife conservation corridor in Tanzania.
36

Effects of Testosterone on the Spatial Ecology, Coloration, and Brain Regions in Western Fence Lizards, Sceloporus occidentalis

Wilson, Rachel Catharine 01 September 2015 (has links) (PDF)
An organism’s spatial ecology allows for access to essential resources such as food, mates, and escape from predators. Home range size, or the total area an organism inhabits, varies in relation to numerous factors including seasonality. During the breeding season, home range size increases in males across taxa. In addition, males usually also have larger home range sizes than females. This implicates testosterone (T) as a possible mediator of this relationship. Indeed, T causes an increase in home range size of males in numerous species of lizards. In addition to T causing an increase in home range size, it also causes an increase in coloration, which is used as a signal to deter or elicit aggressive behaviors in lizards. Potentially, contests are less common in natural settings than in the lab due to this signaling despite increased frequency overlap of home ranges in males. The larger the home range size of males, mediated through an increase in T, the more overlap with conspecifics. With this increase in spatial demand, or home range size, there is often a corresponding increase in spatially related brain regions. In reptiles, these brain regions are the medial and dorsal cortices (MC and DC respectively). The increase in cortical brain region size due to an increase in spatial demand may be mediated by an increase in neurogenesis. Proliferation of neurons occurs along the ventricles and radiate to numerous regions in the brain including the MC. With respect to the MC, immature neurons, which express the protein doublecortin (DCX), migrate from the ventricles, through the inner plexiform layer and are integrated into the cell layer. Because DCX is only expressed in recently born, migrating neurons, it can be used to measure neurogenesis. In mammals and birds, neurogenesis and growth of certain brain regions is affected by steroid hormones, including T. Here we tested two hypotheses: (1) T affects the home range size of Sceloporus occidentalis and (2) cortical brain region volumes are related to home range size and/or T which is mediated through changes in rates of neurogenesis. We surgically castrated individuals and implanted subjects with either a T-filled implant or blank implant and then released them at their initial capture sites. In addition to these castrated individuals, subjects not subjected to castration served as unmanipulated controls. Home range size of individuals in the field was quantified using a global positioning system (GPS) unit and later delineating those GPS points using minimum convex polygons (MCPs). We predicted that (1) castrated, T-treated lizards and unmanipulated control lizards would have larger home range sizes than castrated, control lizards c and (2) MC and DC cortices would be larger in volume and contain more DCX-immunoreactive cells in the lizards with the highest circulating T levels and with the largest home range sizes. We found that increased T caused an increase in the number of blue abdominal scales. We found no differences in home range size relating to T. Likewise, T did not affect MC volumes. However, we did observe a decrease in DC volume with increasing plasma levels of T. Because T did not affect home range size, it follows that we did not find an effect of T on MC volume. However, the significant result of T causing a decrease in DC volume implies a possible trade off with regards to energetics and the maintenance of brain region volumes as prior research indicates that T in increases energy expenditure and decreases foraging efforts.
37

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.
38

Relationship of Ruffed Grouse Home Range Size and Movement to Landscape Characteristics in Southwestern Virginia

Fearer, Todd Matthew 11 June 1999 (has links)
I addressed the effects of landscape characteristics on ruffed grouse (Bonasa umbellus) home range size and movement, and examined grouse selection for specific landscape characteristics and cover types. Grouse home ranges and movement patterns derived from telemetry data gathered from fall 1996 through fall 1998 were overlaid onto a GIS database of Clinch Mtn. Wildlife Management Area, VA. This database was developed from GPS data and LANDSAT thematic mapping imagery (30 m pixel scale) and was composed of 22 cover types. Landscape metrics were calculated using FRAGSTATS/ARC, and multiple regression was used to relate changes in home range size and movement to these metrics. I used Wilcoxon signed-rank tests to compare the values of landscape metrics calculated for each home range to those calculated for the area encompassed by the home range plus a surrounding 300 m buffer. I used Wilcoxon rank-sum tests to compare the values of landscape metrics for the home ranges to the metrics calculated for 50 33 ha random plots. I used compositional analysis to test for preferential use of cover types. I developed 2 regression models (P < 0.01) relating changes in home range size to landscape characteristics, 1 model (P = 0.09) relating the distance between seasonal home range centers to landscape characteristics, and 1 model (P = 0.03) relating average daily movement to landscape characteristics. Grouse home range size increased as patch shape became more irregular and patch size and the number of different cover types per hectare increased, and decreased as the amount of high contrast edge in the landscape increased. The distance between seasonal home range centers increased as Shannon's diversity index and the average distance between patches of similar cover types increased, and decreased as the amount of high contrast edge increased. Average daily movement increased as the average distance between patches of the same cover type increased and as the percent cover of a full (~75%) rhododendron and/or laurel understory within a grouse's home range increased, and decreased as the amount of high contrast edge in a bird's home range increased. Ruffed grouse were selecting areas with high densities of smaller than average patches that were of uniform size and regular shape and contained higher than average amounts of high contrast edge. Areas containing a greater diversity of cover types than what was available in the study area also were preferred. Within these areas, clearcuts and mesic deciduous stands with a rhododendron/laurel understory were the most preferred cover types. Creating and maintaining a landscape with high densities of small patches that are of uniform size and regular (square) shape would provide the highest quality ruffed grouse habitat in this region. Several of these patches should be early successional cover to provide an abundance of high contrast edge. Rhododendron and/or laurel thickets also may be beneficial as supplemental winter cover, and mesic stands of mature hardwoods should be well interspersed with these cover types to provide supplemental food sources. / Master of Science
39

Home range size and habitat use patterns of the Sanderling (Calidris alba) on the Oregon coast nonbreeding range, and comparison with home range sizes in California and Peru

Zeeuw, Maureen L. de, 1961- January 1990 (has links)
Typescript. Includes vita and abstract. Bibliography: Includes bibliographical references (leaves 62-64). / During the nonbreeding season I observed the degree of site faithfulness of individual Sanderlings, Calidris alba, on the Pacific coast of southcentral Oregon, and the linear home range size was estimated. Home range size of Oregon birds and range sizes of individuals wintering in coastal areas of California and Peru were compared to determine if annual migration distance from the high arctic breeding ground is positively correlated with home range size. Oregon sanderlings on average remained within a minimum range of 17 kID during the nonbreeding season from October thrcugh April, although spring data are sparse. The Oregon home range is significantly larger than that of birds in Bodega Bay, California, and similar to that of birds in Peru. Therefore home range size is not correlated with distance from the breeding ground.
40

Utilization of Corridor Habitat by White-tailed Deer (Odocoileus virginianus) in Denton County, Texas

Bruce, Troy Kenneth 05 1900 (has links)
White-tailed deer (Odocoileus virginianus) (N=15) movements were determined with use of radio telemetry techniques to determine the utilization of corridor habitat on the Lake Ray Roberts Greenbelt Corridor (RRGC) in north central Texas. Home ranges were calculated using three estimation types. Male white-tailed deer tend to have home ranges twice that of female home ranges. Seasonal home ranges were largest during spring (Feb. - April) and fall (Aug. - Oct.) seasons. Males had greater seasonal variation in utilization than females. No statistically significant difference (p=0.24) between white-tailed deer locations when the RRGC experiences heavy human traffic compared to days when there is light human traffic. Linearity indices indicated home ranges less linear than expected (LI = 3.02). The RRGC should be maintained at its current status to provide a variety of vegetational types and protective cover for white-tailed deer and other wildlife of Denton County.

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