ERA

Download the full-sized PDF of Human Activity Mediates a Trophic Cascade Caused By WolvesDownload the full-sized PDF

Analytics

Share

Permanent link (DOI): https://doi.org/10.7939/R3CR5NF2D

Download

Export to: EndNote  |  Zotero  |  Mendeley

Communities

This file is in the following communities:

Biological Sciences, Department of

Collections

This file is in the following collections:

Journal Articles (Biological Sciences)

Human Activity Mediates a Trophic Cascade Caused By Wolves Open Access

Descriptions

Author or creator
Hebblewhite, M.
White, C. A.
Nietvelt, C. G.
McKenzie, J. A.
Hurd, T. E.
Fryxell, J. M.
Bayley, S. E.
Paquet, P. C.
Additional contributors
Subject/Keyword
Trophic cascade
Herbivory
Park management
Carnivore
Wolf
Human activity
Predation
Community ecology
Conservation
Predator exclusion
Type of item
Journal Article (Published)
Language
English
Place
Time
Description
Abstract: Experimental evidence of trophic cascades initiated by large vertebrate predators is rare in terrestrial ecosystems. A serendipitous natural experiment provided an opportunity to test the trophic cascade hypothesis for wolves (Canis lupus) in Banff National Park, Canada. The first wolf pack recolonized the Bow Valley of Banff National Park in 1986. High human activity partially excluded wolves from one area of the Bow Valley (low-wolf area), whereas wolves made full use of an adjacent area (high-wolf area). We investigated the effects of differential wolf predation between these two areas on elk (Cervus elaphus) population density, adult female survival, and calf recruitment; aspen (Populus tremuloides) recruitment and browse intensity; willow (Salix spp.) production, browsing intensity, and net growth; beaver (Castor canadensis) density; and riparian songbird diversity, evenness, and abundance. We compared effects of recolonizing wolves on these response variables using the log response ratio between the low-wolf and high-wolf treatments. Elk population density diverged over time in the two treatments, such that elk were an order of magnitude more numerous in the low-wolf area compared to the high-wolf area at the end of the study. Annual survival of adult female elk was 62% in the high-wolf area vs. 89% in the low-wolf area. Annual recruitment of calves was 15% in the high-wolf area vs. 27% without wolves. Wolf exclusion decreased aspen recruitment, willow production, and increased willow and aspen browsing intensity. Beaver lodge density was negatively correlated to elk density, and elk herbivory had an indirect negative effect on riparian songbird diversity and abundance. These alternating patterns across trophic levels support the wolf-caused trophic cascade hypothesis. Human activity strongly mediated these cascade effects, through a depressing effect on habitat use by wolves. Thus, conservation strategies based on the trophic importance of large carnivores have increased support in terrestrial ecosystems.
Date created
2005
DOI
doi:10.7939/R3CR5NF2D
License information
Rights
© 2005 Ecological Society of America. This version of this article is open access and can be downloaded and shared. The original author(s) and source must be cited.
Citation for previous publication
Hebblewhite, M., White, C. A., Nietvelt, C. G., McKenzie, J. A., Hurd, T. E., Fryxell, J. M., Bayley, S. E., & Paquet, P. C. (2005). Human Activity Mediates a Trophic Cascade Caused By Wolves. Ecology, 86(8), 2135-2144. DOI: 10.1890/04-1269.
Source
Link to related item

File Details

Date Uploaded
Date Modified
2014-04-25T00:31:50.445+00:00
Audit Status
Audits have not yet been run on this file.
Characterization
File format: pdf (Portable Document Format)
Mime type: application/pdf
File size: 288593
Last modified: 2015:10:12 16:11:52-06:00
Filename: Ecology_86_2005_2135.pdf
Original checksum: 6253b06bbf1b2f3827d9f9cdb564136c
Well formed: true
Valid: true
File title: ecol_h86_08.2135-2144.tp
File author: leon
Page count: 10
Activity of users you follow
User Activity Date