A model of dominance and resource division among a group of animals of differing quality

Abstract

Individuals of many species spend a large portion of their lives within groups of conspecifics. Within such groups, there can be considerable diversity in size and other traits, with some, perhaps larger or stronger, animals laying claim to a greater than fair share of available resources. We use the word quality as a single measure of individual animal phenotypes within such a group and develop a model of resource division through contests between animals of differing quality. We investigated the effect of varying environmental factors on the level of aggressiveness used in such contests and the division of resources among the group. A numerical example shows that maximum discriminations between individuals on the basis of quality occur for medium-sized costs of aggressive encounters, but resources are divided more equitably at either extreme, when costs are either high or low.