Satiation and the functional response: a test of a new model

Abstract

Abstract. 1. A model of the functional response to prey density is derived to include the reduction in time available for search, T s , resulting from predator satiation. 2. For larger prey items predator satiation occurs at each prey capture and T s is reduced by the attack time and digestive pause of a series of attack cycles. For small prey items predator foraging is continuous at low densities with T s reduced solely by attack time. At higher densities predator satiation occurs after the capture of several small prey items and T s is reduced by the attack time and digestive pause of a series of foraging cycles. 3. A comparison of the predicted asymptotic level of prey capture using experimentally estimated parameter values, with the maximum consumption of aphids by larval and adult coccinellids provides a test of the satiation model. 4. The limitation of prey capture by predator satiation is discussed with reference to handling time and the success of coccinellids in biological control.