Predator-prey dynamics: The interaction among intraspecific competition, predator avoidance, and spatial distributions

Prey interact not only with their predators, but also conspecifics, and must balance the conflicting need of gathering resources and avoiding predation. In this study, I examine the effect of spatial dynamics, predation, and intraspecific competition on predator-prey population dynamics using ordinary, partial, and integro-differential equation models. Specifically, the Rosenzweig-MacArthur predator-prey model is modified to examine the effect that differences between the two species' spatial distributions have on coexistence of predators and prey and the short-term effects of predation on prey aggregations.;In the second chapter, I examine how the number of individual predators or prey in an interaction site alters long-term population dynamics. Two alternative predator situations are studied: predators either allow other individual predators into or exclude them from their foraging area. The per-predator attack rate decreases due to interference interactions in the Poisson-predator model, when predators tolerate additional individuals in a foraging site. When a predators' foraging site covers multiple prey sites, the Territory model results in regions of bistability, wherein the long-term dynamics are determined by initial densities. These bistable regions are not found in the Rosenzweig-MacArthur model or other models of interference. However, the Poisson-predator and Territory models have similarities in stability patterns, indicating a relationship between predator interference interactions and density-dependent predator growth.;In the final chapters, I examine the dynamics of an attractant-mediated prey-grouping model. The third chapter explores the effect of model details by comparing the predicted long-term dynamics of different diffusion model approximations of the integro-differential model. I find that keeping more terms in the approximation increases overall stability. In the fourth chapter, I explore the effects of predation on an attractant-mediated prey grouping system, focusing on the effect of predation on transient aggregations. When prey exhibit intermediate sensitivity to attractant, aggregations form sooner, and last longer than at low sensitivity; however, high sensitivity results in prey reaching spatially homogeneous equilibrium sooner. When predation is considered, the predator-prey population dynamics dominate; however, prey sensitivity affects the length of time between prey cycles.