Home Range in a Patchy Environment: Optimal Foraging Predictions

Optimal foraging rules are used to simulate the home range of a central place forager in an environment with a patchy resource distribution. The model makes the following predictions: (1) Home range size is inversely related to maximum resource density and resource renewal rate. It is positively related to the animal's rate of movement. (2) The optimal home range shape in a patchy environment is elongate rather than circular, with a major to minor axisratio of about 2:1. This agrees well with observed values. (3) The proportion of the total home range used per foraging bout is positively related to the renewal rate of the environment. (4) The tendency of an animal to concentrate its activity in a subregion of the home range (rather than distributing its activity uniformly) will increase with the maximum resource density. This tendency is measured as the ratio of the area which will contain 65% of the occurrences of an animal to the area required to contain 95% of its occurrences. The values of the ratio predicted by this model agree closely with observed values.