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Prey Behavior, Age-Dependent Vulnerability, and Predation Rates
The American Naturalist
  • Susan Lingle, University of Alberta
  • Alex Feldman, Boise State University
  • Mark S. Boyce, University of Alberta
  • W. Finbarr Wilson, McIntyre Ranch Coyote and Deer Project
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Variation in the temporal pattern of vulnerability can provide important insights into predator-prey relationships and the evolution of antipredator behavior. We illustrate these points with a system that has coyotes (Canis latrans) as a predator and two species of congeneric deer (Odocoileus spp.) as prey. The deer employ different antipredator tactics (aggressive defense vs. flight) that result in contrasting patterns of age-dependent vulnerability in their probability of being captured when encountered by coyotes.We use longterm survival data and a simple mathematical model to show that (1) species differences in age-dependent vulnerability are reflected in seasonal predation rates and (2) seasonal variation in prey vulnerability and predator hunt activity, which can be associated with the availability of alternative prey, interact to shape seasonal and annual predation rates for each prey species. Shifting hunt activity from summer to winter, or vice versa, alleviated annual mortality on one species and focused it on the other. Our results indicate that seasonal variation in prey vulnerability and hunt activity interact to influence the impact that a predator has on any particular type of prey. Furthermore, these results indicate that seasonal variation in predation pressure is an important selection pressure shaping prey defenses.
Copyright Statement

This document was originally published by University of Chicago Press in The American Naturalist.

© 2008 by The University of Chicago. All rights reserved. DOI: 10.1086/591675

Citation Information
Susan Lingle, Alex Feldman, Mark S. Boyce and W. Finbarr Wilson. "Prey Behavior, Age-Dependent Vulnerability, and Predation Rates" The American Naturalist (2008)
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