Dynamics of Predators and Prey with Hunting and Escaping Activities in a Landscape with a Prey Refuge

In this study, I constructed an agent-based model to simulate an integrative predator (wolf) -prey (rabbit) -plant (grass) relationship. When a wolf (rabbit) encountered a rabbit (grass), the wolf (rabbit) tended to move to the rabbit (grass) for hunting while the rabbit tended to escape from the wolf. These behaviors were characterized as the degrees of willingness for hunting (H (w) for the wolf and H (r) for the rabbit) and for escaping (E for the rabbit). I distributed prey refuges (with density N) in the grid space. To illustrate the effect of these variables, I plotted H (w) -H (r) grid maps containing information on the population density for each species. I examined how the densities of the three species varied with changes in these variables and analyzed the degree of influence of each variable on the density. Simulation results showed that E had the greatest influence on the ecosystem and that H (r) had the next most important influence. H (w) had the least influence. As N was increased, the effect of E was enhanced. The results mean that in an ecosystem consisting three hierarchical layers with a predation relationship, the species of the middle layer plays an important role in the ecosystem's stability. I briefly discussed how this proposed model can be applied to other ecosystems.