PATCH CHOICE WITH COMPETITIVE ASYMMETRIES AND PERCEPTUAL LIMITS - THEIMPORTANCE OF HISTORY

A model of patch choice, in which individuals choose between two sites with different continuous input rates, is presented. Individuals diff er in their competitive ability and may not perceive small resource di fferences between these patches. The model is historical, in that the individuals are added to the system sequentially, building up a comple te system. Including this historical aspect leads to a different resul t from that derived using equilibrium-centred models. Monte Carlo simu lations of the model show that (1) the historical development of a dis tribution of animals significantly affects its final form, and (2) an equilibrium distribution may not be reached until long after all indiv iduals are present. When individuals have different competitive abilit ies, the 'free' assumption of the ideal free distribution (IFD) is vio lated, giving rise to a distribution we call the ideal competitive-dif ferences distribution (ICDD). As has been previously noted, several di fferent ICDD outcomes are possible in a given situation, but our histo rical perspective suggests that deviations from the habitat-matching p rediction of the IFD (usually undermatchings) are much more likely tha n previously realized. A widely cited example of the ICDD, for instanc e, fails to give the IFD-mimicking habitat-matching distribution as it s most likely outcome. Lastly, perceptual limits in conjunction with c ompetitive differences result in mismatches with the ICDD. It is sugge sted, therefore, that experimental results are likely to undermatch re sources compared with predictions from both the IFD and the ICDD. (C) 1995 The Association for the Study of Animal Behaviour