Wolves influence elk movements: Behavior shapes a trophic cascade in Yellowstone National Park
A trophic cascade recently has been reported among wolves, elk, and aspen on the northern winter range of Yellowstone National Park, Wyoming, USA, but the mechanisms of indirect interactions within this food chain have yet to be established. We investigated whether the observed trophic cascade might...
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Language: | English |
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Ecological Society of America
2005
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Online Access: | https://espace.library.uq.edu.au/view/UQ:e27a60d |
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ftunivqespace:oai:espace.library.uq.edu.au:UQ:e27a60d 2023-05-15T15:51:21+02:00 Wolves influence elk movements: Behavior shapes a trophic cascade in Yellowstone National Park Fortin, Daniel Beyer, Hawthorne L. Boyce, Mark S. Smith, Douglas W. Duchesne, Thierry Mao, Julie S. 2005-01-01 https://espace.library.uq.edu.au/view/UQ:e27a60d eng eng Ecological Society of America doi:10.1890/04-0953 issn:0012-9658 orcid:0000-0002-5430-0784 Aspen Canis lupus Cervus canadensis Conditional logistic regression Elk Habitat selection Movement analysis Populus tremuloides Roads Robust variance Trophic cascade Wolf 1105 Ecology Evolution Behavior and Systematics Journal Article 2005 ftunivqespace https://doi.org/10.1890/04-0953 2020-10-27T05:10:01Z A trophic cascade recently has been reported among wolves, elk, and aspen on the northern winter range of Yellowstone National Park, Wyoming, USA, but the mechanisms of indirect interactions within this food chain have yet to be established. We investigated whether the observed trophic cascade might have a behavioral basis by exploring environmental factors influencing the movements of 13 female elk equipped with GPS radio collars. We developed a simple statistical approach that can unveil the concurrent influence of several environmental features on animal movements. Paths of elk traveling on their winter range were broken down into steps, which correspond to the straight-line segment between successive locations at 5-hour intervals. Each observed step was paired with 200 random steps having the same starting point, but differing in length and/or direction. Comparisons between the characteristics of observed and random steps using conditional logistic regression were used to model environmental features influencing movement patterns. We found that elk movements were influenced by multiple factors, such as the distance from roads, the presence of a steep slope along the step, and the cover type in which they ended. The influence of cover type on elk movements depended on the spatial distribution of wolves across the northern winter range of the park. In low wolf-use areas, the relative preference for end point locations of steps followed: aspen stands > open areas > conifer forests. As the risks of wolf encounter increased, the preference of elk for aspen stands gradually decreased, and selection became strongest for steps ending in conifer forests in high wolf-use areas. Our study clarifies the behavioral mechanisms involved in the trophic cascade of Yellowstone's wolf-elk-aspen system: elk respond to wolves on their winter range by a shift in habitat selection, which leads to local reductions in the use of aspen by elk. Article in Journal/Newspaper Canis lupus The University of Queensland: UQ eSpace Ecology 86 5 1320 1330 |
institution |
Open Polar |
collection |
The University of Queensland: UQ eSpace |
op_collection_id |
ftunivqespace |
language |
English |
topic |
Aspen Canis lupus Cervus canadensis Conditional logistic regression Elk Habitat selection Movement analysis Populus tremuloides Roads Robust variance Trophic cascade Wolf 1105 Ecology Evolution Behavior and Systematics |
spellingShingle |
Aspen Canis lupus Cervus canadensis Conditional logistic regression Elk Habitat selection Movement analysis Populus tremuloides Roads Robust variance Trophic cascade Wolf 1105 Ecology Evolution Behavior and Systematics Fortin, Daniel Beyer, Hawthorne L. Boyce, Mark S. Smith, Douglas W. Duchesne, Thierry Mao, Julie S. Wolves influence elk movements: Behavior shapes a trophic cascade in Yellowstone National Park |
topic_facet |
Aspen Canis lupus Cervus canadensis Conditional logistic regression Elk Habitat selection Movement analysis Populus tremuloides Roads Robust variance Trophic cascade Wolf 1105 Ecology Evolution Behavior and Systematics |
description |
A trophic cascade recently has been reported among wolves, elk, and aspen on the northern winter range of Yellowstone National Park, Wyoming, USA, but the mechanisms of indirect interactions within this food chain have yet to be established. We investigated whether the observed trophic cascade might have a behavioral basis by exploring environmental factors influencing the movements of 13 female elk equipped with GPS radio collars. We developed a simple statistical approach that can unveil the concurrent influence of several environmental features on animal movements. Paths of elk traveling on their winter range were broken down into steps, which correspond to the straight-line segment between successive locations at 5-hour intervals. Each observed step was paired with 200 random steps having the same starting point, but differing in length and/or direction. Comparisons between the characteristics of observed and random steps using conditional logistic regression were used to model environmental features influencing movement patterns. We found that elk movements were influenced by multiple factors, such as the distance from roads, the presence of a steep slope along the step, and the cover type in which they ended. The influence of cover type on elk movements depended on the spatial distribution of wolves across the northern winter range of the park. In low wolf-use areas, the relative preference for end point locations of steps followed: aspen stands > open areas > conifer forests. As the risks of wolf encounter increased, the preference of elk for aspen stands gradually decreased, and selection became strongest for steps ending in conifer forests in high wolf-use areas. Our study clarifies the behavioral mechanisms involved in the trophic cascade of Yellowstone's wolf-elk-aspen system: elk respond to wolves on their winter range by a shift in habitat selection, which leads to local reductions in the use of aspen by elk. |
format |
Article in Journal/Newspaper |
author |
Fortin, Daniel Beyer, Hawthorne L. Boyce, Mark S. Smith, Douglas W. Duchesne, Thierry Mao, Julie S. |
author_facet |
Fortin, Daniel Beyer, Hawthorne L. Boyce, Mark S. Smith, Douglas W. Duchesne, Thierry Mao, Julie S. |
author_sort |
Fortin, Daniel |
title |
Wolves influence elk movements: Behavior shapes a trophic cascade in Yellowstone National Park |
title_short |
Wolves influence elk movements: Behavior shapes a trophic cascade in Yellowstone National Park |
title_full |
Wolves influence elk movements: Behavior shapes a trophic cascade in Yellowstone National Park |
title_fullStr |
Wolves influence elk movements: Behavior shapes a trophic cascade in Yellowstone National Park |
title_full_unstemmed |
Wolves influence elk movements: Behavior shapes a trophic cascade in Yellowstone National Park |
title_sort |
wolves influence elk movements: behavior shapes a trophic cascade in yellowstone national park |
publisher |
Ecological Society of America |
publishDate |
2005 |
url |
https://espace.library.uq.edu.au/view/UQ:e27a60d |
genre |
Canis lupus |
genre_facet |
Canis lupus |
op_relation |
doi:10.1890/04-0953 issn:0012-9658 orcid:0000-0002-5430-0784 |
op_doi |
https://doi.org/10.1890/04-0953 |
container_title |
Ecology |
container_volume |
86 |
container_issue |
5 |
container_start_page |
1320 |
op_container_end_page |
1330 |
_version_ |
1766386534904233984 |