Patch choice under perceptual constraints: a cause for departures from an ideal free distribution
- Cite this article as:
- Abrahams, M.V. Behav Ecol Sociobiol (1986) 19: 409. doi:10.1007/BF00300543
A review of tests of ideal free distribution (IFD) theory reveals a characteristic bias: patches with a small proportion of the resources are relatively overused and patches with a larger proportion of the resources are relatively underused. A model is developed to examine how animals with limited abilities to perceive differences in patch quality affect an IFD by foragers. This constraint produces the observed bias, a bias that is exaggerated as the number of patches increases. Sutherland (1983) has developed a model based on interference which can also explain the observed bias. The two models can be differentiated in that only the perception limit model (this paper) is sensitive to absolute changes in overall resource availability and to increases in the number of animals. Additionally, Sutherland's model predicts that when deviations away from an IFD occur there will be no differences in intake rates, while the perception limit model predicts that intake rates should vary between patches.