Individual patterns of prey selection and dietary specialization in an Arctic marine carnivore
The cumulative effect of individual‐level foraging patterns may have important consequences for ecosystem functioning, population dynamics and conservation. Dietary specialization, whereby an individual exploits a subset of resources available to the rest of the population, can develop in response t...
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crwiley:10.1111/j.1600-0706.2011.19277.x 2023-12-03T10:18:36+01:00 Individual patterns of prey selection and dietary specialization in an Arctic marine carnivore Thiemann, Gregory W. Iverson, Sara J. Stirling, Ian Obbard, Martyn E. 2011 http://dx.doi.org/10.1111/j.1600-0706.2011.19277.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1600-0706.2011.19277.x https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1600-0706.2011.19277.x en eng Wiley http://onlinelibrary.wiley.com/termsAndConditions#vor Oikos volume 120, issue 10, page 1469-1478 ISSN 0030-1299 1600-0706 Ecology, Evolution, Behavior and Systematics journal-article 2011 crwiley https://doi.org/10.1111/j.1600-0706.2011.19277.x 2023-11-09T13:36:52Z The cumulative effect of individual‐level foraging patterns may have important consequences for ecosystem functioning, population dynamics and conservation. Dietary specialization, whereby an individual exploits a subset of resources available to the rest of the population, can develop in response to environmental or intrinsic population factors. However, accurate assessment of individual diets may be difficult because analyses of recent food intake may misrepresent foraging variability within a heterogeneous environment. We used quantitative fatty acid signature analysis (QFASA) and a novel index of longitudinal dietary change to examine the individual foraging patterns of 64 polar bears Ursus maritimus successively sampled in Western and Southern Hudson Bay between 1994–2003. Estimated diets varied between and within age and sex classes, with adult male polar bears consuming significantly more bearded seal Erignathus barbatus than adult female or subadult bears, whose diets were dominated by ringed seal Pusa hispida . Among individual adult males, consumption of bearded seal accounted for 0–98% of the diet and bearded seal consumption was positively correlated with individual dietary specialization, as measured by proportional similarity ( PS i ) to the rest of the population. Most individual diets were consistent from year‐to‐year and were therefore not a product of short‐term heterogeneity in prey distribution. However, a novel dietary change index indicated that adult male polar bears had the most temporally variable diets with 23% of adult males switching their diet from predominantly ringed seal to predominantly bearded seal or vice versa. We conclude that QFASA is well‐suited to analyses of individual‐level foraging because it reflects an animal's diet over the preceding weeks to months. The subpopulations of bears in this study were near the southern limit of their species range and have experienced negative individual‐ and population‐level impacts related to sea ice loss and climate warming. The ... Article in Journal/Newspaper Arctic bearded seal Erignathus barbatus Hudson Bay Pusa hispida ringed seal Sea ice Ursus maritimus Wiley Online Library (via Crossref) Arctic Hudson Bay Hudson Oikos 120 10 1469 1478 |
institution |
Open Polar |
collection |
Wiley Online Library (via Crossref) |
op_collection_id |
crwiley |
language |
English |
topic |
Ecology, Evolution, Behavior and Systematics |
spellingShingle |
Ecology, Evolution, Behavior and Systematics Thiemann, Gregory W. Iverson, Sara J. Stirling, Ian Obbard, Martyn E. Individual patterns of prey selection and dietary specialization in an Arctic marine carnivore |
topic_facet |
Ecology, Evolution, Behavior and Systematics |
description |
The cumulative effect of individual‐level foraging patterns may have important consequences for ecosystem functioning, population dynamics and conservation. Dietary specialization, whereby an individual exploits a subset of resources available to the rest of the population, can develop in response to environmental or intrinsic population factors. However, accurate assessment of individual diets may be difficult because analyses of recent food intake may misrepresent foraging variability within a heterogeneous environment. We used quantitative fatty acid signature analysis (QFASA) and a novel index of longitudinal dietary change to examine the individual foraging patterns of 64 polar bears Ursus maritimus successively sampled in Western and Southern Hudson Bay between 1994–2003. Estimated diets varied between and within age and sex classes, with adult male polar bears consuming significantly more bearded seal Erignathus barbatus than adult female or subadult bears, whose diets were dominated by ringed seal Pusa hispida . Among individual adult males, consumption of bearded seal accounted for 0–98% of the diet and bearded seal consumption was positively correlated with individual dietary specialization, as measured by proportional similarity ( PS i ) to the rest of the population. Most individual diets were consistent from year‐to‐year and were therefore not a product of short‐term heterogeneity in prey distribution. However, a novel dietary change index indicated that adult male polar bears had the most temporally variable diets with 23% of adult males switching their diet from predominantly ringed seal to predominantly bearded seal or vice versa. We conclude that QFASA is well‐suited to analyses of individual‐level foraging because it reflects an animal's diet over the preceding weeks to months. The subpopulations of bears in this study were near the southern limit of their species range and have experienced negative individual‐ and population‐level impacts related to sea ice loss and climate warming. The ... |
format |
Article in Journal/Newspaper |
author |
Thiemann, Gregory W. Iverson, Sara J. Stirling, Ian Obbard, Martyn E. |
author_facet |
Thiemann, Gregory W. Iverson, Sara J. Stirling, Ian Obbard, Martyn E. |
author_sort |
Thiemann, Gregory W. |
title |
Individual patterns of prey selection and dietary specialization in an Arctic marine carnivore |
title_short |
Individual patterns of prey selection and dietary specialization in an Arctic marine carnivore |
title_full |
Individual patterns of prey selection and dietary specialization in an Arctic marine carnivore |
title_fullStr |
Individual patterns of prey selection and dietary specialization in an Arctic marine carnivore |
title_full_unstemmed |
Individual patterns of prey selection and dietary specialization in an Arctic marine carnivore |
title_sort |
individual patterns of prey selection and dietary specialization in an arctic marine carnivore |
publisher |
Wiley |
publishDate |
2011 |
url |
http://dx.doi.org/10.1111/j.1600-0706.2011.19277.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1600-0706.2011.19277.x https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1600-0706.2011.19277.x |
geographic |
Arctic Hudson Bay Hudson |
geographic_facet |
Arctic Hudson Bay Hudson |
genre |
Arctic bearded seal Erignathus barbatus Hudson Bay Pusa hispida ringed seal Sea ice Ursus maritimus |
genre_facet |
Arctic bearded seal Erignathus barbatus Hudson Bay Pusa hispida ringed seal Sea ice Ursus maritimus |
op_source |
Oikos volume 120, issue 10, page 1469-1478 ISSN 0030-1299 1600-0706 |
op_rights |
http://onlinelibrary.wiley.com/termsAndConditions#vor |
op_doi |
https://doi.org/10.1111/j.1600-0706.2011.19277.x |
container_title |
Oikos |
container_volume |
120 |
container_issue |
10 |
container_start_page |
1469 |
op_container_end_page |
1478 |
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1784265610652286976 |