Diet and Macronutrient Optimization in Wild Ursids: A Comparison of Grizzly Bears with Sympatric and Allopatric Black Bears
When fed ad libitum, ursids can maximize mass gain by selecting mixed diets wherein protein provides 17 ± 4% of digestible energy, relative to carbohydrates or lipids. In the wild, this ability is likely constrained by seasonal food availability, limits of intake rate as body size increases, and com...
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Online Access: | http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4871523/ http://www.ncbi.nlm.nih.gov/pubmed/27192407 https://doi.org/10.1371/journal.pone.0153702 |
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ftpubmed:oai:pubmedcentral.nih.gov:4871523 2023-05-15T18:42:18+02:00 Diet and Macronutrient Optimization in Wild Ursids: A Comparison of Grizzly Bears with Sympatric and Allopatric Black Bears Costello, Cecily M. Cain, Steven L. Pils, Shannon Frattaroli, Leslie Haroldson, Mark A. van Manen, Frank T. 2016-05-18 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4871523/ http://www.ncbi.nlm.nih.gov/pubmed/27192407 https://doi.org/10.1371/journal.pone.0153702 en eng Public Library of Science http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4871523/ http://www.ncbi.nlm.nih.gov/pubmed/27192407 http://dx.doi.org/10.1371/journal.pone.0153702 https://creativecommons.org/publicdomain/zero/1.0/ This is an open access article, free of all copyright, and may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose. The work is made available under the Creative Commons CC0 (https://creativecommons.org/publicdomain/zero/1.0/) public domain dedication. CC0 PDM Research Article Text 2016 ftpubmed https://doi.org/10.1371/journal.pone.0153702 2016-06-05T00:30:07Z When fed ad libitum, ursids can maximize mass gain by selecting mixed diets wherein protein provides 17 ± 4% of digestible energy, relative to carbohydrates or lipids. In the wild, this ability is likely constrained by seasonal food availability, limits of intake rate as body size increases, and competition. By visiting locations of 37 individuals during 274 bear-days, we documented foods consumed by grizzly (Ursus arctos) and black bears (Ursus americanus) in Grand Teton National Park during 2004–2006. Based on published nutritional data, we estimated foods and macronutrients as percentages of daily energy intake. Using principal components and cluster analyses, we identified 14 daily diet types. Only 4 diets, accounting for 21% of days, provided protein levels within the optimal range. Nine diets (75% of days) led to over-consumption of protein, and 1 diet (3% of days) led to under-consumption. Highest protein levels were associated with animal matter (i.e., insects, vertebrates), which accounted for 46–47% of daily energy for both species. As predicted: 1) daily diets dominated by high-energy vertebrates were positively associated with grizzly bears and mean percent protein intake was positively associated with body mass; 2) diets dominated by low-protein fruits were positively associated with smaller-bodied black bears; and 3) mean protein was highest during spring, when high-energy plant foods were scarce, however it was also higher than optimal during summer and fall. Contrary to our prediction: 4) allopatric black bears did not exhibit food selection for high-energy foods similar to grizzly bears. Although optimal gain of body mass was typically constrained, bears usually opted for the energetically superior trade-off of consuming high-energy, high-protein foods. Given protein digestion efficiency similar to obligate carnivores, this choice likely supported mass gain, consistent with studies showing monthly increases in percent body fat among bears in this region. Text Ursus arctos PubMed Central (PMC) PLOS ONE 11 5 e0153702 |
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Research Article Costello, Cecily M. Cain, Steven L. Pils, Shannon Frattaroli, Leslie Haroldson, Mark A. van Manen, Frank T. Diet and Macronutrient Optimization in Wild Ursids: A Comparison of Grizzly Bears with Sympatric and Allopatric Black Bears |
topic_facet |
Research Article |
description |
When fed ad libitum, ursids can maximize mass gain by selecting mixed diets wherein protein provides 17 ± 4% of digestible energy, relative to carbohydrates or lipids. In the wild, this ability is likely constrained by seasonal food availability, limits of intake rate as body size increases, and competition. By visiting locations of 37 individuals during 274 bear-days, we documented foods consumed by grizzly (Ursus arctos) and black bears (Ursus americanus) in Grand Teton National Park during 2004–2006. Based on published nutritional data, we estimated foods and macronutrients as percentages of daily energy intake. Using principal components and cluster analyses, we identified 14 daily diet types. Only 4 diets, accounting for 21% of days, provided protein levels within the optimal range. Nine diets (75% of days) led to over-consumption of protein, and 1 diet (3% of days) led to under-consumption. Highest protein levels were associated with animal matter (i.e., insects, vertebrates), which accounted for 46–47% of daily energy for both species. As predicted: 1) daily diets dominated by high-energy vertebrates were positively associated with grizzly bears and mean percent protein intake was positively associated with body mass; 2) diets dominated by low-protein fruits were positively associated with smaller-bodied black bears; and 3) mean protein was highest during spring, when high-energy plant foods were scarce, however it was also higher than optimal during summer and fall. Contrary to our prediction: 4) allopatric black bears did not exhibit food selection for high-energy foods similar to grizzly bears. Although optimal gain of body mass was typically constrained, bears usually opted for the energetically superior trade-off of consuming high-energy, high-protein foods. Given protein digestion efficiency similar to obligate carnivores, this choice likely supported mass gain, consistent with studies showing monthly increases in percent body fat among bears in this region. |
format |
Text |
author |
Costello, Cecily M. Cain, Steven L. Pils, Shannon Frattaroli, Leslie Haroldson, Mark A. van Manen, Frank T. |
author_facet |
Costello, Cecily M. Cain, Steven L. Pils, Shannon Frattaroli, Leslie Haroldson, Mark A. van Manen, Frank T. |
author_sort |
Costello, Cecily M. |
title |
Diet and Macronutrient Optimization in Wild Ursids: A Comparison of Grizzly Bears with Sympatric and Allopatric Black Bears |
title_short |
Diet and Macronutrient Optimization in Wild Ursids: A Comparison of Grizzly Bears with Sympatric and Allopatric Black Bears |
title_full |
Diet and Macronutrient Optimization in Wild Ursids: A Comparison of Grizzly Bears with Sympatric and Allopatric Black Bears |
title_fullStr |
Diet and Macronutrient Optimization in Wild Ursids: A Comparison of Grizzly Bears with Sympatric and Allopatric Black Bears |
title_full_unstemmed |
Diet and Macronutrient Optimization in Wild Ursids: A Comparison of Grizzly Bears with Sympatric and Allopatric Black Bears |
title_sort |
diet and macronutrient optimization in wild ursids: a comparison of grizzly bears with sympatric and allopatric black bears |
publisher |
Public Library of Science |
publishDate |
2016 |
url |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4871523/ http://www.ncbi.nlm.nih.gov/pubmed/27192407 https://doi.org/10.1371/journal.pone.0153702 |
genre |
Ursus arctos |
genre_facet |
Ursus arctos |
op_relation |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4871523/ http://www.ncbi.nlm.nih.gov/pubmed/27192407 http://dx.doi.org/10.1371/journal.pone.0153702 |
op_rights |
https://creativecommons.org/publicdomain/zero/1.0/ This is an open access article, free of all copyright, and may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose. The work is made available under the Creative Commons CC0 (https://creativecommons.org/publicdomain/zero/1.0/) public domain dedication. |
op_rightsnorm |
CC0 PDM |
op_doi |
https://doi.org/10.1371/journal.pone.0153702 |
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PLOS ONE |
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11 |
container_issue |
5 |
container_start_page |
e0153702 |
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