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Journal Article

Trade‐offs between predation risk and forage differ between migrant strategies in a migratory ungulate

Mark Hebblewhite; Evelyn H. Merrill
Ecology · Vol. 90, Issue 12 · pp. 3445-3454 · 2009

Abstract

Trade‐offs between predation risk and forage fundamentally drive resource selection by animals. Among migratory ungulates, trade‐offs can occur at large spatial scales through migration, which allows an “escape” from predation, but trade‐offs can also occur at finer spatial scales. Previous authors suggest that ungulates will avoid predation risk at the largest scale, although few studies have examined multi‐scale trade‐offs to test for the relative benefits of risk avoidance across scales. Building on previously developed spatial models of forage and wolf predation risk, we tested for trade‐offs at the broad landscape scale and at a finer, within‐home‐range scale for migratory and non‐migratory resident elk ( Cervus elaphus ) during summer in the Canadian Rockies in Banff National Park (BNP) and adjacent Alberta, Canada. Migration reduced exposure to wolf predation risk by 70% relative to residents at the landscape scale; at the fine scale, migrants used areas that were, on average, 6% higher in forage digestibility. In contrast, by forgoing migration, resident elk were exposed to higher predation risk, but they reduced predation risk at fine scales to only 15% higher than migrants by using areas close to human activity, which wolves avoided. Thus, residents paid for trying to avoid predation risk with lower forage quality. Residents may have been able to compensate, however, by using areas of abundant forage close to human activity where they may have been able to forage more selectively while avoiding predation risk. Human activity effectively decoupled the positive correlation between high forage quality and wolf predation, providing an effective alternate strategy for residents, similar to recent findings in other systems. Although ungulates appear capable of balancing risk and forage at different spatial scales, risk avoidance at large landscape scales may be more effective in the absence of human‐caused refugia from predation.

Bibliographic Information

JournalEcology
PublisherWiley
Publication Date2009-12-01
Publication Year2009
Volume90
Issue12
Pages3445-3454
Document TypeJournal Article
Print ISSN0012-9658
eISSN1939-9170
DOI10.1890/08-2090.1
SubjectEcology & Organismal Biology

Access Information

NARA Access Coverage1997-01-01~Current
Journal Homepagehttps://esajournals.onlinelibrary.wiley.com/loi/19399170
Publisher PageOpen Publisher Page
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