INTERFERENCE AND THE IDEAL FREE DISTRIBUTION - MODELS AND TESTS

We review the assumptions and predictions of five competitive distribu tion models that predict how optimal foragers will be distributed acro ss resource patches when gains are reduced by interference. This revie w revealed a number of previously ignored predictions and assumptions: in particular, there should be no change in relative patch use as com petitor density changes. A new model is proposed in which interference results from the costs of encounters with other foragers and where th e gains on a patch are independent of the costs of interference. This model predicts that as density increases, there will be increased prop ortional use of lower-quality patches. Past empirical studies of inter ference distributions are reanalyzed; none of the studies provides str ong support for any of the existing ideal free-distribution models. We suggest that previous results are more consistent with the prediction s of our new model.