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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

The Spatial Ecology of Eastern Hognose Snakes (Heterodon platirhinos): Habitat Selection, Home Range Size, and the Effect of Roads on Movement Patterns

Robson, Laura E 30 November 2011 (has links)
Habitat loss is the greatest contributor to the decline of species globally and thus understanding habitat use and the consequences fragmentation has on biodiversity is a fundamental step towards management and recovery. I conducted a radio-telemetry study to examine the spatial ecology and the effects of roads on Eastern Hognose Snakes (Heterodon platirhinos), a species at risk, in the Long Point Region of Ontario, Canada. I tested habitat selection at multiple spatial scales and I found that within the home range, snakes avoided agricultural land and selected open sand barrens, particularly for nesting. At the local scale, snakes avoided mature overstory trees and used younger patches of forest. Used locations had more woody debris, logs and low-vegetative coverage than locations selected at random. Eastern Hognose Snakes also showed avoidance of paved road crossings in their seasonal movements, but readily crossed unpaved roads. Management efforts for this species at risk should be placed on the conservation of sand barrens and on the construction of road underpasses to prevent genetic isolation of populations.
2

The Spatial Ecology of Eastern Hognose Snakes (Heterodon platirhinos): Habitat Selection, Home Range Size, and the Effect of Roads on Movement Patterns

Robson, Laura E 30 November 2011 (has links)
Habitat loss is the greatest contributor to the decline of species globally and thus understanding habitat use and the consequences fragmentation has on biodiversity is a fundamental step towards management and recovery. I conducted a radio-telemetry study to examine the spatial ecology and the effects of roads on Eastern Hognose Snakes (Heterodon platirhinos), a species at risk, in the Long Point Region of Ontario, Canada. I tested habitat selection at multiple spatial scales and I found that within the home range, snakes avoided agricultural land and selected open sand barrens, particularly for nesting. At the local scale, snakes avoided mature overstory trees and used younger patches of forest. Used locations had more woody debris, logs and low-vegetative coverage than locations selected at random. Eastern Hognose Snakes also showed avoidance of paved road crossings in their seasonal movements, but readily crossed unpaved roads. Management efforts for this species at risk should be placed on the conservation of sand barrens and on the construction of road underpasses to prevent genetic isolation of populations.
3

WILDLIFE ROAD MORTALITY ON THE 1000 ISLANDS PARKWAY IN SOUTH EASTERN ONTARIO: PEAK TIMES, HOT SPOTS, AND MITIGATION USING DRAINAGE CULVERTS

Garrah, Evelyn 31 May 2012 (has links)
Road mortality threatens the long-term viability of some wildlife populations, particularly herpetofauna. Wildlife road mortalities were recorded during regular bicycle-based surveys of the 1000 Islands Parkway in south eastern Ontario during 2010 and 2011. These data were grouped with similar data collected in 2008 and 2009 to determine when and where animals were killed along the Parkway to better inform mitigation options. Temporal and spatial clustering was significant for five taxonomic groups: snakes were found dead on the road primarily in September, turtles in June, frogs in July, and birds and mammals in June and July. The majority of turtles found on the Parkway were adult females, which may have implications for long-term population demographics and persistence. Regression tree analysis indicates day-of-year as the most important variable in explaining wildlife road mortality for all taxonomic groups, with higher road mortalities coinciding with higher minimum daily temperature. Precipitation and traffic accounted for little variation in snake road mortality, and had no effect on turtle, frog, bird or mammal road kills. Spatial clustering was found for all taxonomic groups with overlapping areas of significant clustering between years identified as hot spots. In addition, the potential for drainage culverts to reduce wildlife road mortality was tested with two experimental treatments in 2010: (1) blocked culverts to prevent wildlife use, and (2) drift fence installation adjacent to culverts to encourage wildlife use. Wildlife road mortalities at these locations as well as control culverts were compared with 2008 wildlife road mortalities when there were no culvert treatments. The number of road kills in the area of treatments was too low to measure changes for all taxa but frogs, which showed no significant changes in road kills for any culvert treatment. The results of the study are used to evaluate a list of potential options for mitigating wildlife road mortality along the Parkway, and a list of implementable actions is identified. / Thesis (Master, Environmental Studies) -- Queen's University, 2012-05-31 16:33:51.623
4

The Spatial Ecology of Eastern Hognose Snakes (Heterodon platirhinos): Habitat Selection, Home Range Size, and the Effect of Roads on Movement Patterns

Robson, Laura E 30 November 2011 (has links)
Habitat loss is the greatest contributor to the decline of species globally and thus understanding habitat use and the consequences fragmentation has on biodiversity is a fundamental step towards management and recovery. I conducted a radio-telemetry study to examine the spatial ecology and the effects of roads on Eastern Hognose Snakes (Heterodon platirhinos), a species at risk, in the Long Point Region of Ontario, Canada. I tested habitat selection at multiple spatial scales and I found that within the home range, snakes avoided agricultural land and selected open sand barrens, particularly for nesting. At the local scale, snakes avoided mature overstory trees and used younger patches of forest. Used locations had more woody debris, logs and low-vegetative coverage than locations selected at random. Eastern Hognose Snakes also showed avoidance of paved road crossings in their seasonal movements, but readily crossed unpaved roads. Management efforts for this species at risk should be placed on the conservation of sand barrens and on the construction of road underpasses to prevent genetic isolation of populations.
5

The Spatial Ecology of Eastern Hognose Snakes (Heterodon platirhinos): Habitat Selection, Home Range Size, and the Effect of Roads on Movement Patterns

Robson, Laura E January 2011 (has links)
Habitat loss is the greatest contributor to the decline of species globally and thus understanding habitat use and the consequences fragmentation has on biodiversity is a fundamental step towards management and recovery. I conducted a radio-telemetry study to examine the spatial ecology and the effects of roads on Eastern Hognose Snakes (Heterodon platirhinos), a species at risk, in the Long Point Region of Ontario, Canada. I tested habitat selection at multiple spatial scales and I found that within the home range, snakes avoided agricultural land and selected open sand barrens, particularly for nesting. At the local scale, snakes avoided mature overstory trees and used younger patches of forest. Used locations had more woody debris, logs and low-vegetative coverage than locations selected at random. Eastern Hognose Snakes also showed avoidance of paved road crossings in their seasonal movements, but readily crossed unpaved roads. Management efforts for this species at risk should be placed on the conservation of sand barrens and on the construction of road underpasses to prevent genetic isolation of populations.
6

Wildlife-Vehicle Collisions in Utah: An Analysis of Wildlife Road Mortality Hotspots, Economic Impacts and Implications for Mitigation and Management

Kassar, Christine A 01 May 2005 (has links)
In the US, the roaded landscape has had serious ecological effects. We studied wildlife-vehicle collisions occurring on the 248 state routes in Utah from 1992 to 2002. We tracked trends and patterns in deer-vehicle collisions, evaluated all routes for frequency of deer kills, and identified "hotspots" ( segments of road with high concentrations of collisions per mile). We found pronounced patterns: e.g., 61.15% of all collisions occurred on only 10 routes. We studied the effects of posted speed limit and annual average daily traffic flow and found that no relationship existed between traffic volume and/or posted speed limit and the number of wildlife-vehicle collisions that occurred. We put the economic costs associated with wildlife vehicle collisions into a public safety perspective and confirmed that associated costs, damage, injuries, and loss of resources are significant aspects ofDVCs that require attention and justify mitigation.
7

Using Spatial Approaches to Examine Threats Facing Common Snapping Turtles (Chelydra Serpentina) in the Urbanized Cootes Paradise Marsh, Lake Ontario

Piczak, Morgan January 2018 (has links)
In Ontario, the common snapping turtle, Chelydra serpentina, is listed as Special Concern and is at risk of decline. These long-lived organisms are particularly susceptible to anthropogenic threats owing to delayed sexual maturity, low recruitment and reliance on low adult mortality. Threats facing this species include road mortality and habitat loss and/or destruction. These threats are anecdotally evident within Cootes Paradise Marsh, a highly urbanized river-mouth coastal marsh located in a heavily urbanized region at the western end of Lake Ontario. Straddling Dundas and Hamilton, the wetland is bisected by Cootes Drive, a four-lane highway (maximum speed 80 km/h) that has resulted in fatal collisions with wildlife. We re-analyzed data from previous capture-mark-recapture studies and determined that the snapping turtle population has declined by almost 90% from 1985 to 2002. Using road mortality survey data collected by citizen science group Dundas Turtle Watch, we determined that some of this decline can be attributed to road mortality. Through radio tracking, we also found that the population remains at risk to road mortalities because their home ranges overlap surrounding roads. Besides the direct negative effect of mortality, roads impart broader and additional unintended consequences by hindering turtles’ access to critical nesting and overwintering habitat. We acquired digital orthophotos to assess changes in availability of nesting habitat, which is crucial for recruitment and population maintenance. Potential nesting habitat decreased by almost 50% between 1934 and 2010. Through nest surveys conducted in 2017, we determined that there is currently disproportionate use of artificial gravel mounds for nesting. For overwintering purposes, snapping turtles appear to be using a wide range of habitat types within the upland terrestrial matrix of the wetland ecosystem. We also confirmed that sites used for overwintering did not cool below inhibiting temperatures between early December and end of March. This study illustrates the toll that road mortality can have on urbanized herpetofauna populations and highlights the importance of ensuring that recovery plans focus on restoring both the quantity and quality of nesting and overwintering habitats. / Thesis / Master of Science (MSc) / Common snapping turtles (Chelydra serpentina) exhibit “slow” life history traits which make them particularly vulnerable to human activities, such as urbanization. In this thesis, I used demographic and road mortality information to provide evidence that the population of snapping turtles living in the degraded Cootes Paradise Marsh ecosystem has substantially declined over the past three decades. I also assessed current availability of nesting and overwintering habitat that are both essential for maintaining a viable population of snapping turtles. My results highlight the devastating effects road mortality can impart on long-lived freshwater reptiles, and cautions against further modification or destruction of their critical habitat.
8

Pohybová aktivita užovky stromové v Poohří ve vztahu k silničnímu tělesu / Movement activity of Aesculapian Snake in Poohří in relation to the roadway

LAPÁČKOVÁ, Kateřina January 2015 (has links)
This thesis is focused on explaining the behaviour of population of Aesculapian Snake (Zamenis longissimus) in Poohří region related to a busy road which crosses its area of distribution. To avoid the busy road Aesculapian Snake uses the roads culverts to cross the road safely. Snakes used culverts the most often on July, when their activity culminates. One of the most used culverts was culvert Nr. 2, probably because of its proximity to man-made hatch. Snakes started their activity at 8:00 a.m. and finished at 7:00 p.m. In this study their activity culminates between 4:00 p.m. and 6:00 p.m. and by temperature between 21 - 25°C. None of adults of Aesculapian Snake was detected killed on the road. There were found only juvenile snakes of this species which weren't acquainted yet with local threats.

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