Spatiotemporal behavior of a prey-predator system with a group defense for prey

Group defense is a strategy widely employed by various species. We consider the effect of grouping on population persistence when animals join together in herds in order to provide a self-defense from predators. In literature, group defense is usually addressed in terms of individual behavioral responses. In this paper, we consider an alternative 'mean-field' approach which uses prey and predator densities as the dynamical variables. The model is essentially a predator-prey system but with an unconventional parametrization for the predation term. We discuss the outcomes of the ecosystem dynamics in terms of persistence and prey survival. In the spatially distributed model some specific spatio-temporal features are discovered. (C) 2013 Elsevier B.V. All rights reserved.