Ecological stability and social hierarchy

We have examined a predator-prey model in which the predator is assumed to have a social structure of the dominance hierarchy or “peck order” type in which the feeding success of an individual is related both to the availability of food and to his social rank. We find such a social structure to be a strongly beneficial influence on population stability so long as the rewards of social dominance are not too extreme. We also show that an optimally hierarchical predator population can stably achieve a much larger depression of the prey below its carrying capacity than is possible for a simple predator population composed of identical individuals. This strongly suggests that socially structured predator populations may be more effective agents of biological control than simpler predators with no such population structure.