Despotism and risk of infanticide influence grizzly bear den-site selection.

Given documented social dominance and intraspecific predation in bear populations, the ideal despotic distribution model and sex hypothesis of sexual segregation predict adult female grizzly bears (Ursus arctos) will avoid areas occupied by adult males to reduce risk of infanticide. Under ideal desp...

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Main Authors: Nathan S Libal, Jerrold L Belant, Bruce D Leopold, Guiming Wang, Patricia A Owen
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2011-01-01
Series:PLoS ONE
Online Access:http://europepmc.org/articles/PMC3173359?pdf=render
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author Nathan S Libal
Jerrold L Belant
Bruce D Leopold
Guiming Wang
Patricia A Owen
author_facet Nathan S Libal
Jerrold L Belant
Bruce D Leopold
Guiming Wang
Patricia A Owen
author_sort Nathan S Libal
collection DOAJ
description Given documented social dominance and intraspecific predation in bear populations, the ideal despotic distribution model and sex hypothesis of sexual segregation predict adult female grizzly bears (Ursus arctos) will avoid areas occupied by adult males to reduce risk of infanticide. Under ideal despotic distribution, juveniles should similarly avoid adult males to reduce predation risk. Den-site selection and use is an important component of grizzly bear ecology and may be influenced by multiple factors, including risk from conspecifics. To test the role of predation risk and the sex hypothesis of sexual segregation, we compared adult female (n = 142), adult male (n = 36), and juvenile (n = 35) den locations in Denali National Park and Preserve, Alaska, USA. We measured elevation, aspect, slope, and dominant land cover for each den site, and used maximum entropy modeling to determine which variables best predicted den sites. We identified the global model as the best-fitting model for adult female (area under curve (AUC) = 0.926) and elevation as the best predictive variable for adult male (AUC = 0.880) den sites. The model containing land cover and elevation best-predicted juvenile (AUC = 0.841) den sites. Adult females spatially segregated from adult males, with dens characterized by higher elevations (mean= 1,412 m, SE = 52) and steeper slopes (mean = 21.9°, SE = 1.1) than adult male (elevation: mean = 1,209 m, SE = 76; slope: mean = 15.6°, SE = 1.9) den sites. Juveniles used a broad range of landscape attributes but did not avoid adult male denning areas. Observed spatial segregation by adult females supports the sex hypothesis of sexual segregation and we suggest is a mechanism to reduce risk of infanticide. Den site selection of adult males is likely related to distribution of food resources during spring.
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spelling doaj.art-611c89a10b0f4de8a79e168327abc6f62022-12-22T01:13:56ZengPublic Library of Science (PLoS)PLoS ONE1932-62032011-01-0169e2413310.1371/journal.pone.0024133Despotism and risk of infanticide influence grizzly bear den-site selection.Nathan S LibalJerrold L BelantBruce D LeopoldGuiming WangPatricia A OwenGiven documented social dominance and intraspecific predation in bear populations, the ideal despotic distribution model and sex hypothesis of sexual segregation predict adult female grizzly bears (Ursus arctos) will avoid areas occupied by adult males to reduce risk of infanticide. Under ideal despotic distribution, juveniles should similarly avoid adult males to reduce predation risk. Den-site selection and use is an important component of grizzly bear ecology and may be influenced by multiple factors, including risk from conspecifics. To test the role of predation risk and the sex hypothesis of sexual segregation, we compared adult female (n = 142), adult male (n = 36), and juvenile (n = 35) den locations in Denali National Park and Preserve, Alaska, USA. We measured elevation, aspect, slope, and dominant land cover for each den site, and used maximum entropy modeling to determine which variables best predicted den sites. We identified the global model as the best-fitting model for adult female (area under curve (AUC) = 0.926) and elevation as the best predictive variable for adult male (AUC = 0.880) den sites. The model containing land cover and elevation best-predicted juvenile (AUC = 0.841) den sites. Adult females spatially segregated from adult males, with dens characterized by higher elevations (mean= 1,412 m, SE = 52) and steeper slopes (mean = 21.9°, SE = 1.1) than adult male (elevation: mean = 1,209 m, SE = 76; slope: mean = 15.6°, SE = 1.9) den sites. Juveniles used a broad range of landscape attributes but did not avoid adult male denning areas. Observed spatial segregation by adult females supports the sex hypothesis of sexual segregation and we suggest is a mechanism to reduce risk of infanticide. Den site selection of adult males is likely related to distribution of food resources during spring.http://europepmc.org/articles/PMC3173359?pdf=render
spellingShingle Nathan S Libal
Jerrold L Belant
Bruce D Leopold
Guiming Wang
Patricia A Owen
Despotism and risk of infanticide influence grizzly bear den-site selection.
PLoS ONE
title Despotism and risk of infanticide influence grizzly bear den-site selection.
title_full Despotism and risk of infanticide influence grizzly bear den-site selection.
title_fullStr Despotism and risk of infanticide influence grizzly bear den-site selection.
title_full_unstemmed Despotism and risk of infanticide influence grizzly bear den-site selection.
title_short Despotism and risk of infanticide influence grizzly bear den-site selection.
title_sort despotism and risk of infanticide influence grizzly bear den site selection
url http://europepmc.org/articles/PMC3173359?pdf=render
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