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Whitebark Pine, Population Density, and Home-Range Size of Grizzly Bears in the Greater Yellowstone Ecosystem

Changes in life history traits of species can be an important indicator of potential factors influencing populations. For grizzly bears (Ursus arctos) in the Greater Yellowstone Ecosystem (GYE), recent decline of whitebark pine (WBP; Pinus albicaulis), an important fall food resource, has been paire...

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Autores principales: Bjornlie, Daniel D., Van Manen, Frank T., Ebinger, Michael R., Haroldson, Mark A., Thompson, Daniel J., Costello, Cecily M.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Public Library of Science 2014
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3919729/
https://www.ncbi.nlm.nih.gov/pubmed/24520354
http://dx.doi.org/10.1371/journal.pone.0088160
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author Bjornlie, Daniel D.
Van Manen, Frank T.
Ebinger, Michael R.
Haroldson, Mark A.
Thompson, Daniel J.
Costello, Cecily M.
author_facet Bjornlie, Daniel D.
Van Manen, Frank T.
Ebinger, Michael R.
Haroldson, Mark A.
Thompson, Daniel J.
Costello, Cecily M.
author_sort Bjornlie, Daniel D.
collection PubMed
description Changes in life history traits of species can be an important indicator of potential factors influencing populations. For grizzly bears (Ursus arctos) in the Greater Yellowstone Ecosystem (GYE), recent decline of whitebark pine (WBP; Pinus albicaulis), an important fall food resource, has been paired with a slowing of population growth following two decades of robust population increase. These observations have raised questions whether resource decline or density-dependent processes may be associated with changes in population growth. Distinguishing these effects based on changes in demographic rates can be difficult. However, unlike the parallel demographic responses expected from both decreasing food availability and increasing population density, we hypothesized opposing behavioral responses of grizzly bears with regard to changes in home-range size. We used the dynamic changes in food resources and population density of grizzly bears as a natural experiment to examine hypotheses regarding these potentially competing influences on grizzly bear home-range size. We found that home-range size did not increase during the period of whitebark pine decline and was not related to proportion of whitebark pine in home ranges. However, female home-range size was negatively associated with an index of population density. Our data indicate that home-range size of grizzly bears in the GYE is not associated with availability of WBP, and, for female grizzly bears, increasing population density may constrain home-range size.
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spelling pubmed-39197292014-02-11 Whitebark Pine, Population Density, and Home-Range Size of Grizzly Bears in the Greater Yellowstone Ecosystem Bjornlie, Daniel D. Van Manen, Frank T. Ebinger, Michael R. Haroldson, Mark A. Thompson, Daniel J. Costello, Cecily M. PLoS One Research Article Changes in life history traits of species can be an important indicator of potential factors influencing populations. For grizzly bears (Ursus arctos) in the Greater Yellowstone Ecosystem (GYE), recent decline of whitebark pine (WBP; Pinus albicaulis), an important fall food resource, has been paired with a slowing of population growth following two decades of robust population increase. These observations have raised questions whether resource decline or density-dependent processes may be associated with changes in population growth. Distinguishing these effects based on changes in demographic rates can be difficult. However, unlike the parallel demographic responses expected from both decreasing food availability and increasing population density, we hypothesized opposing behavioral responses of grizzly bears with regard to changes in home-range size. We used the dynamic changes in food resources and population density of grizzly bears as a natural experiment to examine hypotheses regarding these potentially competing influences on grizzly bear home-range size. We found that home-range size did not increase during the period of whitebark pine decline and was not related to proportion of whitebark pine in home ranges. However, female home-range size was negatively associated with an index of population density. Our data indicate that home-range size of grizzly bears in the GYE is not associated with availability of WBP, and, for female grizzly bears, increasing population density may constrain home-range size. Public Library of Science 2014-02-10 /pmc/articles/PMC3919729/ /pubmed/24520354 http://dx.doi.org/10.1371/journal.pone.0088160 Text en https://creativecommons.org/publicdomain/zero/1.0/ This is an open-access article distributed under the terms of the Creative Commons Public Domain declaration, which stipulates that, once placed in the public domain, this work may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose.
spellingShingle Research Article
Bjornlie, Daniel D.
Van Manen, Frank T.
Ebinger, Michael R.
Haroldson, Mark A.
Thompson, Daniel J.
Costello, Cecily M.
Whitebark Pine, Population Density, and Home-Range Size of Grizzly Bears in the Greater Yellowstone Ecosystem
title Whitebark Pine, Population Density, and Home-Range Size of Grizzly Bears in the Greater Yellowstone Ecosystem
title_full Whitebark Pine, Population Density, and Home-Range Size of Grizzly Bears in the Greater Yellowstone Ecosystem
title_fullStr Whitebark Pine, Population Density, and Home-Range Size of Grizzly Bears in the Greater Yellowstone Ecosystem
title_full_unstemmed Whitebark Pine, Population Density, and Home-Range Size of Grizzly Bears in the Greater Yellowstone Ecosystem
title_short Whitebark Pine, Population Density, and Home-Range Size of Grizzly Bears in the Greater Yellowstone Ecosystem
title_sort whitebark pine, population density, and home-range size of grizzly bears in the greater yellowstone ecosystem
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3919729/
https://www.ncbi.nlm.nih.gov/pubmed/24520354
http://dx.doi.org/10.1371/journal.pone.0088160
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