Optimal movement strategies for social foragers in unpredictable environments

  • Hancock P
  • Milner-Gulland E
  • 133

    Readers

    Mendeley users who have this article in their library.
  • 24

    Citations

    Citations of this article.

Abstract

Spatial movement models often base movement decision rules on traditional optimal foraging theories, including ideal free distribution (IFD) theory, more recently generalized as density-dependent habitat selection (DDHS) theory, and the marginal value theorem (MVT). Thus optimal patch departure times are predicted on the basis of the density-dependent resource level in the patch. Recently, alternatives to density as a habitat selection criterion, such as individual knowledge of the resource distribution, conspecific attraction, and site fidelity, have been recognized as important influences on movement behavior in environments with an uncertain resource distribution. For foraging processes incorporating these influences, it is not clear whether simple optimal foraging theories provide a reasonable approximation to animal behavior or whether they may be misleading. This study compares patch departure strategies predicted by DDHS theory and the MVT with evolutionarily optimal patch departure strategies for a wide range of foraging scenarios. The level of accuracy with which individuals can navigate toward local food sources is varied, and individual tendency for conspecific attraction or repulsion is optimized over a continuous spectrum. We find that DDHS theory and the MVT accurately predict the evolutionarily optimal patch departure strategy for foragers with high navigational accuracy for a wide range of resource distributions. As navigational accuracy is reduced, the patch departure strategy cannot be accurately predicted by these theories for environments with a heterogeneous resource distribution. In these situations, social forces improve foraging success and have a strong influence on optimal patch departure strategies, causing individuals to stay longer in patches than the optimal foraging theories predict. [ABSTRACT FROM AUTHOR]

Author-supplied keywords

  • Density-dependent habitat selection
  • Foraging theory
  • Genetic algorithm
  • Ideal free distribution
  • Individual-based model
  • Marginal value theorem
  • Optimal patch use
  • Spatial movement models

Get free article suggestions today

Mendeley saves you time finding and organizing research

Sign up here
Already have an account ?Sign in

Find this document

Authors

  • Penelope A. Hancock

  • E. J. Milner-Gulland

Cite this document

Choose a citation style from the tabs below

Save time finding and organizing research with Mendeley

Sign up for free