Value of Clumping to Prey and the Evolutionary Response of Ambush Predators

Abstract

Predatory success and the evolution of body size in ambush predators appear to be strongly influenced by the pattern of distribution of prey. A model of predation as a stochastic queuing process predicts that, under nearly all circumstances, clumping benefits the prey and hurts the predator. A measure of fitness derived from the difference between the mean rates of predation and energy use indicates that selection for an optimum gut size will become increasingly strong as the prey aggregate.