Foraging behavior has always been a central concern of ecology. Understanding what animals eat is clearly an essential component of under standing many ecological issues including energy flow, competition and adaptation. Theoretical and empirical developments in the late 1960's and 1970's led to a new emphasis in the study of foraging behavior, the study of individual animals in both field and laboratory. This development, in turn, led to an explosion of interest in foraging. Part of the reason for this explosion is that when foraging is studied at the individual level, it is relevant to many...