Prey interact with their predators and a community of competing species, and must balance the conflicting needs of gathering resources and avoiding being eaten. The interaction between competition for resources and predation is summarized using a diamond food web, where one predator feeds on two alternative types of prey sharing a common resource. Predictions from current ecological theory, based on well-mixed, non-spatial systems, often contradict experimental results. The proposed research examines the effect of differences in the use of space by the prey and predator on the interaction between predation and competition using a combination of differential equation and simulation models. The research will focus on how coexistence is affected by differences in the size of sites used or defended by predators and prey, and the influence of prey grouping on the balance between resource utilization and predator avoidance. It builds on current research concerning the effect of space on simple predator-prey interactions, the effect of differences between sites and the theory of the effect of predation on resource competition in well-mixed systems. The proposed research's intellectual merit is that it will inform biologists about the conditions under which differences in predator and prey spatial scales and distributions are important to community dynamics. The broad impact of this research will produce software package and other educational benefits.
