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

Mark Hebblewhite, Evelyn H. Merrill

Research output: Contribution to journalArticlepeer-review

265 Scopus citations


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.

Original languageEnglish
Pages (from-to)3445-3454
Number of pages10
Issue number12
StatePublished - Dec 2009


  • Alberta
  • Banff National Park
  • Canada
  • Cervus elaphus
  • Elk
  • Habitat selection
  • Migration
  • Partial migration
  • Refugia
  • Risk - forage trade-off
  • Wolf predation


Dive into the research topics of 'Trade-offs between predation risk and forage differ between migrant strategies in a migratory ungulate'. Together they form a unique fingerprint.

Cite this