Evaluation of indicators of stress in populations of polar bears (Ursus maritimus) and grizzly bears (Ursus arctos)
Grizzly and polar bears are both species at the top of the food chain in their respective ecosystems, and as such are indicative of the overall health of the ecosystem. Presently there is little data regarding the stress status of these animals. The development of reliable indicators of stress is im...
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University of Waterloo
2008
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ftunivwaterloo:oai:uwspace.uwaterloo.ca:10012/3488 2023-05-15T18:18:50+02:00 Evaluation of indicators of stress in populations of polar bears (Ursus maritimus) and grizzly bears (Ursus arctos) Hamilton, Jason 2008-01-07 http://hdl.handle.net/10012/3488 en eng University of Waterloo http://hdl.handle.net/10012/3488 Stress indicators Bears Biology Master Thesis 2008 ftunivwaterloo 2022-06-18T22:58:11Z Grizzly and polar bears are both species at the top of the food chain in their respective ecosystems, and as such are indicative of the overall health of the ecosystem. Presently there is little data regarding the stress status of these animals. The development of reliable indicators of stress is important as both species face rapid environmental change. Polar bears from Hudson’s Bay (Ontario, Canada) and grizzly bears from Alberta, Canada, were anaesthetized and blood samples retrieved. Samples were assayed for changes in serum-based indicators of stress. Serum cortisol levels, the predominant corticosteroid in mammals and a commonly used indicator of stress, was measured to evaluate its potential as a chronic stress indicator in bears. The induction time of the cortisol response to stressor exposure is rapid and will be influenced by the stress relating to capture. Hence, serum levels of heat shock proteins (hsps), specifically the 60 (hsp60) and 70 kilodalton (hsp70) families of hsps were also measured to evaluate their reliability as a stress indicator in bears. Traditionally, heat shock proteins have been measured in tissues; however recent studies have indicated their presence in serum in response to chronic stress. In addition, the study examined the feasibility of using corticosteroid-binding globulin (CBG), a serum protein that binds cortisol, as a stress indicator in bears. CBG regulates the availability of cortisol to the tissues (only unbound cortisol elicits a response) but unlike cortisol is not rapidly regulated by acute stress. Bear CBG was isolated and a specific anti-bear CBG antibody was generated. The development of an enzyme-linked immunoadsorbant assay (ELISA) using this bear anti-CBG has the potential to be a useful tool to determine longer-term stress response in bears. Known life-history variables were correlated to the observed levels of serum indicators to elucidate which environmental factors impact bears. The length of sea ice coverage was the strongest determinant of serum cortisol ... Master Thesis Sea ice Ursus arctos Ursus maritimus University of Waterloo, Canada: Institutional Repository Canada |
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Open Polar |
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University of Waterloo, Canada: Institutional Repository |
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ftunivwaterloo |
language |
English |
topic |
Stress indicators Bears Biology |
spellingShingle |
Stress indicators Bears Biology Hamilton, Jason Evaluation of indicators of stress in populations of polar bears (Ursus maritimus) and grizzly bears (Ursus arctos) |
topic_facet |
Stress indicators Bears Biology |
description |
Grizzly and polar bears are both species at the top of the food chain in their respective ecosystems, and as such are indicative of the overall health of the ecosystem. Presently there is little data regarding the stress status of these animals. The development of reliable indicators of stress is important as both species face rapid environmental change. Polar bears from Hudson’s Bay (Ontario, Canada) and grizzly bears from Alberta, Canada, were anaesthetized and blood samples retrieved. Samples were assayed for changes in serum-based indicators of stress. Serum cortisol levels, the predominant corticosteroid in mammals and a commonly used indicator of stress, was measured to evaluate its potential as a chronic stress indicator in bears. The induction time of the cortisol response to stressor exposure is rapid and will be influenced by the stress relating to capture. Hence, serum levels of heat shock proteins (hsps), specifically the 60 (hsp60) and 70 kilodalton (hsp70) families of hsps were also measured to evaluate their reliability as a stress indicator in bears. Traditionally, heat shock proteins have been measured in tissues; however recent studies have indicated their presence in serum in response to chronic stress. In addition, the study examined the feasibility of using corticosteroid-binding globulin (CBG), a serum protein that binds cortisol, as a stress indicator in bears. CBG regulates the availability of cortisol to the tissues (only unbound cortisol elicits a response) but unlike cortisol is not rapidly regulated by acute stress. Bear CBG was isolated and a specific anti-bear CBG antibody was generated. The development of an enzyme-linked immunoadsorbant assay (ELISA) using this bear anti-CBG has the potential to be a useful tool to determine longer-term stress response in bears. Known life-history variables were correlated to the observed levels of serum indicators to elucidate which environmental factors impact bears. The length of sea ice coverage was the strongest determinant of serum cortisol ... |
format |
Master Thesis |
author |
Hamilton, Jason |
author_facet |
Hamilton, Jason |
author_sort |
Hamilton, Jason |
title |
Evaluation of indicators of stress in populations of polar bears (Ursus maritimus) and grizzly bears (Ursus arctos) |
title_short |
Evaluation of indicators of stress in populations of polar bears (Ursus maritimus) and grizzly bears (Ursus arctos) |
title_full |
Evaluation of indicators of stress in populations of polar bears (Ursus maritimus) and grizzly bears (Ursus arctos) |
title_fullStr |
Evaluation of indicators of stress in populations of polar bears (Ursus maritimus) and grizzly bears (Ursus arctos) |
title_full_unstemmed |
Evaluation of indicators of stress in populations of polar bears (Ursus maritimus) and grizzly bears (Ursus arctos) |
title_sort |
evaluation of indicators of stress in populations of polar bears (ursus maritimus) and grizzly bears (ursus arctos) |
publisher |
University of Waterloo |
publishDate |
2008 |
url |
http://hdl.handle.net/10012/3488 |
geographic |
Canada |
geographic_facet |
Canada |
genre |
Sea ice Ursus arctos Ursus maritimus |
genre_facet |
Sea ice Ursus arctos Ursus maritimus |
op_relation |
http://hdl.handle.net/10012/3488 |
_version_ |
1766195547039858688 |