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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

Effects of tundra vehicle activity on polar bears (Ursus maritimus) at Churchill, Manitoba

Dyck, Markus Guido, January 2001 (has links) (PDF)
Thesis (M.N.R.M.)--University of Manitoba, 2001. / Includes bibliographical references (leaves 119-138).
2

Physical characteristics of polar bear winter sea ice habitat

Blouw, Christina 26 August 2008 (has links)
Accumulation of dynamic and thermodynamic forces in the Arctic are decreasing the extent of thin annual sea ice which polar bear rely on for survival. It is imperative that we identify the preferred habitat of polar bears to fully understand their future requirements. In this thesis, surveys of polar bear tracks and the surrounding sea ice variables, at various scales, were recorded. Sea ice roughness was measured through surveys of the sample area in situ, with an electromagnetic induction (EM) system (IcePIC) mounted to a helicopter, and analyzed through advanced synthetic aperture radar (ASAR) images of the study area. In situ Polar bear tracks provided a limited association with the EM sea ice roughness and a negative association to ASAR sea ice roughness. Results indicate a significant association between EM mean values and ASAR brightness means. In addition, EM statistics and ASAR texture statistics were correlated through a best fit regression model. These associations display a remote method to identify preferred polar bear habitat and provide a potential linkage between the regional (EM) and remotely sensed (ASAR) assessment of sea ice roughness. / October 2008
3

Physical characteristics of polar bear winter sea ice habitat

Blouw, Christina 26 August 2008 (has links)
Accumulation of dynamic and thermodynamic forces in the Arctic are decreasing the extent of thin annual sea ice which polar bear rely on for survival. It is imperative that we identify the preferred habitat of polar bears to fully understand their future requirements. In this thesis, surveys of polar bear tracks and the surrounding sea ice variables, at various scales, were recorded. Sea ice roughness was measured through surveys of the sample area in situ, with an electromagnetic induction (EM) system (IcePIC) mounted to a helicopter, and analyzed through advanced synthetic aperture radar (ASAR) images of the study area. In situ Polar bear tracks provided a limited association with the EM sea ice roughness and a negative association to ASAR sea ice roughness. Results indicate a significant association between EM mean values and ASAR brightness means. In addition, EM statistics and ASAR texture statistics were correlated through a best fit regression model. These associations display a remote method to identify preferred polar bear habitat and provide a potential linkage between the regional (EM) and remotely sensed (ASAR) assessment of sea ice roughness.
4

Physical characteristics of polar bear winter sea ice habitat

Blouw, Christina 26 August 2008 (has links)
Accumulation of dynamic and thermodynamic forces in the Arctic are decreasing the extent of thin annual sea ice which polar bear rely on for survival. It is imperative that we identify the preferred habitat of polar bears to fully understand their future requirements. In this thesis, surveys of polar bear tracks and the surrounding sea ice variables, at various scales, were recorded. Sea ice roughness was measured through surveys of the sample area in situ, with an electromagnetic induction (EM) system (IcePIC) mounted to a helicopter, and analyzed through advanced synthetic aperture radar (ASAR) images of the study area. In situ Polar bear tracks provided a limited association with the EM sea ice roughness and a negative association to ASAR sea ice roughness. Results indicate a significant association between EM mean values and ASAR brightness means. In addition, EM statistics and ASAR texture statistics were correlated through a best fit regression model. These associations display a remote method to identify preferred polar bear habitat and provide a potential linkage between the regional (EM) and remotely sensed (ASAR) assessment of sea ice roughness.
5

RELIABILITY, ACCURACY, AND TRACKING TECHNIQUES OF INUIT HUNTERS IN ESTIMATING POLAR BEAR CHARACTERISTICS FROM TRACKS

WONG, PAMELA 17 August 2010 (has links)
Inuit estimates of polar bear characteristics from tracks could complement ongoing capture-mark-recapture methods to frequently monitor polar bear populations in response to climate-induced habitat changes. Before the inclusion of these Inuit track estimates, they need to be evaluated for reliability and accuracy. Building on previous work, which showed increased reliability among active Inuit hunters, this thesis research reports i) reliability in estimates of sex, age, size, and age of track of a larger number of tracks by a larger number of Inuit hunters; ii) preliminary accuracy assessments of sex and size estimates; iii) semi-structured interviews with Inuit hunters regarding their polar bear tracking experience and techniques; and iv) potential relations between Inuit hunting experience and reliability and accuracy in diagnosing tracks. The Inuit hunters were reliable and consistent as a group in making estimates of sex (α=0.74 and mean corrected item-total correlation=0.45), age (α=0.81 and mean corrected item-total correlation=0.63), and size (α=0.91 and mean corrected item-total correlation=0.73), as well as age of track estimates with the exclusion of a single participant (α=0.85 and mean corrected item-total correlation=0.63). Preliminary accuracy assessments suggest Inuit hunters are generally accurate in their estimates of sex (mean 65.28% agreement with genetic sex estimates) and potentially size from tracks, warranting further efforts to determine accuracy in these estimates as well as age and age of track. Semi-structured, open-ended interviews with each hunter revealed they use similar tracking techniques, which may explain their high agreement in making estimates. In addition, Inuit tracking experience and the use of particular tracking methods may correlate with individual reliability and accuracy in track diagnoses. These results suggest the information that Inuit hunters provide may inform any tracking-based polar bear survey. / Thesis (Master, Biology) -- Queen's University, 2010-08-15 13:06:07.948
6

Modeling sea ice in Hudson Bay from a polar bear (Ursus maritimus) perspective

Castro de la Guardia, Laura Unknown Date
No description available.
7

Designing for pedestrians in a landscape of rational fear: Churchill, Manitoba

Kirouac, Rachelle L. 09 April 2015 (has links)
The intent of this practicum is to improve pedestrian access in and around Churchill. Challenges and causes for rational fear in the landscape were identified and paths and mechanisms were designed to mitigate these concerns. The purpose is to make the landscape a more welcoming place that can be enjoyed and celebrated by a wider range of users.
8

The development of multi-level governance for the management of polar bears in Nunavut Territory, Canada

Dowsley, Martha Gwynne McCall. January 1900 (has links)
Thesis (Ph.D.). / Written for the Dept. of Geography. Title from title page of PDF (viewed 2008/05/09). Includes bibliographical references.
9

Evaluating the Use of Fecal Transthyretin as a Biomarker for Noninvasive Pregnancy Diagnosis in the Polar Bear (Ursus maritimus)

DeLorenzo, Corrina J. January 2017 (has links)
No description available.
10

The Effects Of Ecotourism On Polar Bear Behavior

Eckhardt, Gillian 01 January 2005 (has links)
Polar bears spend the majority of their lives on the sea ice, where they gain access to seals and mates. In western Hudson Bay, the sea ice melts for three to four months in the summer, and polar bears there are forced onto land. These bears live on their fat reserves for the duration of the iceless period, until temperatures get colder in the fall and freeze up begins. The aggregation of polar bears near Churchill, Manitoba during the ice free period has led to a thriving tourist industry, with a large influx of tourists visiting Churchill in the fall in a six to eight week period, yet little is known about the impacts of this industry on the biology of the bears. This study investigated the effect of tourist vehicles and human presence on the behavior of polar bears over the fall of 2003 and 2004. Overall time budgets were estimated for bears, and the behavior of males and females was compared. Females spent significantly less time lying and more time in locomotion than males. Time budgets were also estimated for bears in the presence and absence of tourist vehicles. Bears spent less time lying and more time in a sit/stand position in the presence of vehicles. Air temperature had no significant effect on the time budgets of polar bears. Tundra vehicle approaches were manipulated to determine effects on polar bear behavior, and to investigate any variables that significantly affected response, including habituation. A response was defined as any sudden whole body movement or change in position or behavior at the time of approach. A total of 25% of all bears responded to the experimental vehicle approach. For bears that responded to approach, the average distance at response was 43 m. The average speed of the vehicle was 0.66 ± 0.02 m/s (range 0.23 to 1.15 m/s). Approach variables that significantly influenced the likelihood of response of a bear to an approaching vehicle included angle of approach and vehicle speed. Direct approaches, in which the bear was in the path of the moving vehicle, had a higher probability of eliciting a response than indirect approaches, in which the vehicle stayed to one side of the bear at all times. Higher speeds of the vehicle increased the probability of a response by a bear. Behaviors of the bear that significantly predicted a response were shifting of the body and smacking of the lips. A playback study was conducted to determine the effects of human induced sound on polar bears. There was no significant effect of human sound on polar bears. Results presented here provide the first experimental evidence of variables in the tourist industry that affect polar bear behavior, and the first evidence of behavioral cues predicting a response to vehicle approach.

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