OPTIMAL PATCH USE BY A TERRITORIAL FORAGER

The marginal value theorem (MVT) describes when a forager should leave a patch if it is to maximize its long-term rate of energetic gain. The theorem states that the forager should leave a patch when its instantaneous rate of energy gain in that patch falls to the overall rate of the environment. One of the assumptions on which this result rests is that there is little or no revisitation of patches. In this paper we explore the consequences of maximizing long-term rate of energetic gain in an environment in which patches are revisited. We have in mind a territorial species that systematically exploits patches in which food renews. We compare the predictions of our model with those of the MVT and discuss their implications for laboratory and field experiments of patch use theory. The coupling of resource dyanmics to a behavioural model is an important feature of our approach. © 1990 Academic Press Limited.