Maternal carryover, winter severity, and brown bear abundance relate to elk demographics
Ungulates are key components of ecosystems due to their effects on lower trophic levels, role as prey, and value for recreational and subsistence harvests. Understanding factors that drive ungulate population dynamics can inform protection of important habitat and successful management of population...
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Online Access: | http://dx.doi.org/10.1371/journal.pone.0274359 https://dx.plos.org/10.1371/journal.pone.0274359 |
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crplos:10.1371/journal.pone.0274359 2024-05-19T07:49:48+00:00 Maternal carryover, winter severity, and brown bear abundance relate to elk demographics Schooler, Sarah L. Svoboda, Nathan J. Finnegan, Shannon P. Crye, John Kellner, Kenneth F. Belant, Jerrold L. Weckerly, Floyd W U.S. Fish and Wildlife Service Rocky Mountain Elk Foundation 2022 http://dx.doi.org/10.1371/journal.pone.0274359 https://dx.plos.org/10.1371/journal.pone.0274359 en eng Public Library of Science (PLoS) http://creativecommons.org/licenses/by/4.0/ PLOS ONE volume 17, issue 9, page e0274359 ISSN 1932-6203 journal-article 2022 crplos https://doi.org/10.1371/journal.pone.0274359 2024-05-01T07:04:32Z Ungulates are key components of ecosystems due to their effects on lower trophic levels, role as prey, and value for recreational and subsistence harvests. Understanding factors that drive ungulate population dynamics can inform protection of important habitat and successful management of populations. To ascertain correlates of ungulate population dynamics, we evaluated the effects of five non-exclusive hypotheses on ungulate abundance and recruitment: winter severity, spring nutritional limitation (spring bottleneck), summer-autumn maternal condition carryover, predation, and timber harvest. We used weather, reconstructed brown bear ( Ursus arctos ) abundance, and timber harvest data to estimate support for these hypotheses on early calf recruitment (calves per 100 adult females in July–August) and population counts of Roosevelt elk ( Cervus canadensis roosevelti ) on Afognak and Raspberry islands, Alaska, USA, 1958–2020. Increasing winter temperatures positively affected elk abundance, supporting the winter severity hypothesis, while a later first fall freeze had a positive effect on elk recruitment, supporting the maternal carry-over hypothesis. Increased brown bear abundance was negatively associated with elk recruitment, supporting the predation hypothesis. Recruitment was unaffected by spring climate conditions or timber harvest. Severe winter weather likely increased elk energy deficits, reducing elk survival and subsequent abundance in the following year. Colder and shorter falls likely reduced late-season forage, resulting in poor maternal condition which limited elk recruitment more than winter severity or late-winter nutritional bottlenecks. Our results additionally demonstrated potential negative effects of brown bears on elk recruitment. The apparent long-term decline in elk recruitment did not result in a decline of abundance, which suggests that less severe winters may increase elk survival and counteract the potential effects of predation on elk abundance. Article in Journal/Newspaper Ursus arctos Alaska PLOS PLOS ONE 17 9 e0274359 |
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English |
description |
Ungulates are key components of ecosystems due to their effects on lower trophic levels, role as prey, and value for recreational and subsistence harvests. Understanding factors that drive ungulate population dynamics can inform protection of important habitat and successful management of populations. To ascertain correlates of ungulate population dynamics, we evaluated the effects of five non-exclusive hypotheses on ungulate abundance and recruitment: winter severity, spring nutritional limitation (spring bottleneck), summer-autumn maternal condition carryover, predation, and timber harvest. We used weather, reconstructed brown bear ( Ursus arctos ) abundance, and timber harvest data to estimate support for these hypotheses on early calf recruitment (calves per 100 adult females in July–August) and population counts of Roosevelt elk ( Cervus canadensis roosevelti ) on Afognak and Raspberry islands, Alaska, USA, 1958–2020. Increasing winter temperatures positively affected elk abundance, supporting the winter severity hypothesis, while a later first fall freeze had a positive effect on elk recruitment, supporting the maternal carry-over hypothesis. Increased brown bear abundance was negatively associated with elk recruitment, supporting the predation hypothesis. Recruitment was unaffected by spring climate conditions or timber harvest. Severe winter weather likely increased elk energy deficits, reducing elk survival and subsequent abundance in the following year. Colder and shorter falls likely reduced late-season forage, resulting in poor maternal condition which limited elk recruitment more than winter severity or late-winter nutritional bottlenecks. Our results additionally demonstrated potential negative effects of brown bears on elk recruitment. The apparent long-term decline in elk recruitment did not result in a decline of abundance, which suggests that less severe winters may increase elk survival and counteract the potential effects of predation on elk abundance. |
author2 |
Weckerly, Floyd W U.S. Fish and Wildlife Service Rocky Mountain Elk Foundation |
format |
Article in Journal/Newspaper |
author |
Schooler, Sarah L. Svoboda, Nathan J. Finnegan, Shannon P. Crye, John Kellner, Kenneth F. Belant, Jerrold L. |
spellingShingle |
Schooler, Sarah L. Svoboda, Nathan J. Finnegan, Shannon P. Crye, John Kellner, Kenneth F. Belant, Jerrold L. Maternal carryover, winter severity, and brown bear abundance relate to elk demographics |
author_facet |
Schooler, Sarah L. Svoboda, Nathan J. Finnegan, Shannon P. Crye, John Kellner, Kenneth F. Belant, Jerrold L. |
author_sort |
Schooler, Sarah L. |
title |
Maternal carryover, winter severity, and brown bear abundance relate to elk demographics |
title_short |
Maternal carryover, winter severity, and brown bear abundance relate to elk demographics |
title_full |
Maternal carryover, winter severity, and brown bear abundance relate to elk demographics |
title_fullStr |
Maternal carryover, winter severity, and brown bear abundance relate to elk demographics |
title_full_unstemmed |
Maternal carryover, winter severity, and brown bear abundance relate to elk demographics |
title_sort |
maternal carryover, winter severity, and brown bear abundance relate to elk demographics |
publisher |
Public Library of Science (PLoS) |
publishDate |
2022 |
url |
http://dx.doi.org/10.1371/journal.pone.0274359 https://dx.plos.org/10.1371/journal.pone.0274359 |
genre |
Ursus arctos Alaska |
genre_facet |
Ursus arctos Alaska |
op_source |
PLOS ONE volume 17, issue 9, page e0274359 ISSN 1932-6203 |
op_rights |
http://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.1371/journal.pone.0274359 |
container_title |
PLOS ONE |
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17 |
container_issue |
9 |
container_start_page |
e0274359 |
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