Isotopic homogeneity of breath CO 2 from fasting and berry-eating polar bears: implications for tracing reliance on terrestrial foods in a changing Arctic
With a changing Arctic climate, it is important to know whether polar bears ( Ursus maritimus Phipps, 1774) can supplement their stored fat reserves by intake of terrestrial berries. Although polar bears are known to consume berries while on land, it has been difficult to quantify their relative dep...
Published in: | Canadian Journal of Zoology |
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Canadian Science Publishing
2009
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Online Access: | http://dx.doi.org/10.1139/z08-137 http://www.nrcresearchpress.com/doi/full-xml/10.1139/Z08-137 http://www.nrcresearchpress.com/doi/pdf/10.1139/Z08-137 |
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crcansciencepubl:10.1139/z08-137 2023-12-17T10:25:36+01:00 Isotopic homogeneity of breath CO 2 from fasting and berry-eating polar bears: implications for tracing reliance on terrestrial foods in a changing Arctic Hobson, K. A. Stirling, I. Andriashek, D. S. 2009 http://dx.doi.org/10.1139/z08-137 http://www.nrcresearchpress.com/doi/full-xml/10.1139/Z08-137 http://www.nrcresearchpress.com/doi/pdf/10.1139/Z08-137 en eng Canadian Science Publishing http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining Canadian Journal of Zoology volume 87, issue 1, page 50-55 ISSN 0008-4301 1480-3283 Animal Science and Zoology Ecology, Evolution, Behavior and Systematics journal-article 2009 crcansciencepubl https://doi.org/10.1139/z08-137 2023-11-19T13:38:33Z With a changing Arctic climate, it is important to know whether polar bears ( Ursus maritimus Phipps, 1774) can supplement their stored fat reserves by intake of terrestrial berries. Although polar bears are known to consume berries while on land, it has been difficult to quantify their relative dependence on stored adipose tissue and berry carbohydrates to meet their energy needs. We sampled breath CO 2 from 300 bears fasting on land in western Hudson Bay during the open-water seasons of 1997 and 1998 and analyzed this breath for stable carbon isotope (δ 13 C) values. We found no difference in the bear breath δ 13 C values for bears known to have recently fed on berries and those that had not. The distribution of δ 13 C values was remarkably tight with average values ranging from –24.2‰ to –24.8‰ with no effect of age, sex, or year of capture. This result was counter to our simple isotopic discrimination model that predicted bears metabolizing adipose tissue derived from seals would have breath δ 13 C values close to –24.7‰ and those metabolizing berries exclusively would have values close to –32.6‰. If correct, our results suggests that the bears which had fed on berries while fasting on land received an insignificant amount of energetic benefit. Article in Journal/Newspaper Arctic Hudson Bay Ursus maritimus Canadian Science Publishing (via Crossref) Arctic Hudson Bay Hudson Canadian Journal of Zoology 87 1 50 55 |
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Open Polar |
collection |
Canadian Science Publishing (via Crossref) |
op_collection_id |
crcansciencepubl |
language |
English |
topic |
Animal Science and Zoology Ecology, Evolution, Behavior and Systematics |
spellingShingle |
Animal Science and Zoology Ecology, Evolution, Behavior and Systematics Hobson, K. A. Stirling, I. Andriashek, D. S. Isotopic homogeneity of breath CO 2 from fasting and berry-eating polar bears: implications for tracing reliance on terrestrial foods in a changing Arctic |
topic_facet |
Animal Science and Zoology Ecology, Evolution, Behavior and Systematics |
description |
With a changing Arctic climate, it is important to know whether polar bears ( Ursus maritimus Phipps, 1774) can supplement their stored fat reserves by intake of terrestrial berries. Although polar bears are known to consume berries while on land, it has been difficult to quantify their relative dependence on stored adipose tissue and berry carbohydrates to meet their energy needs. We sampled breath CO 2 from 300 bears fasting on land in western Hudson Bay during the open-water seasons of 1997 and 1998 and analyzed this breath for stable carbon isotope (δ 13 C) values. We found no difference in the bear breath δ 13 C values for bears known to have recently fed on berries and those that had not. The distribution of δ 13 C values was remarkably tight with average values ranging from –24.2‰ to –24.8‰ with no effect of age, sex, or year of capture. This result was counter to our simple isotopic discrimination model that predicted bears metabolizing adipose tissue derived from seals would have breath δ 13 C values close to –24.7‰ and those metabolizing berries exclusively would have values close to –32.6‰. If correct, our results suggests that the bears which had fed on berries while fasting on land received an insignificant amount of energetic benefit. |
format |
Article in Journal/Newspaper |
author |
Hobson, K. A. Stirling, I. Andriashek, D. S. |
author_facet |
Hobson, K. A. Stirling, I. Andriashek, D. S. |
author_sort |
Hobson, K. A. |
title |
Isotopic homogeneity of breath CO 2 from fasting and berry-eating polar bears: implications for tracing reliance on terrestrial foods in a changing Arctic |
title_short |
Isotopic homogeneity of breath CO 2 from fasting and berry-eating polar bears: implications for tracing reliance on terrestrial foods in a changing Arctic |
title_full |
Isotopic homogeneity of breath CO 2 from fasting and berry-eating polar bears: implications for tracing reliance on terrestrial foods in a changing Arctic |
title_fullStr |
Isotopic homogeneity of breath CO 2 from fasting and berry-eating polar bears: implications for tracing reliance on terrestrial foods in a changing Arctic |
title_full_unstemmed |
Isotopic homogeneity of breath CO 2 from fasting and berry-eating polar bears: implications for tracing reliance on terrestrial foods in a changing Arctic |
title_sort |
isotopic homogeneity of breath co 2 from fasting and berry-eating polar bears: implications for tracing reliance on terrestrial foods in a changing arctic |
publisher |
Canadian Science Publishing |
publishDate |
2009 |
url |
http://dx.doi.org/10.1139/z08-137 http://www.nrcresearchpress.com/doi/full-xml/10.1139/Z08-137 http://www.nrcresearchpress.com/doi/pdf/10.1139/Z08-137 |
geographic |
Arctic Hudson Bay Hudson |
geographic_facet |
Arctic Hudson Bay Hudson |
genre |
Arctic Hudson Bay Ursus maritimus |
genre_facet |
Arctic Hudson Bay Ursus maritimus |
op_source |
Canadian Journal of Zoology volume 87, issue 1, page 50-55 ISSN 0008-4301 1480-3283 |
op_rights |
http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining |
op_doi |
https://doi.org/10.1139/z08-137 |
container_title |
Canadian Journal of Zoology |
container_volume |
87 |
container_issue |
1 |
container_start_page |
50 |
op_container_end_page |
55 |
_version_ |
1785577229025017856 |