Using spatially explicit random walk models of animal movement as a tool for the outline of conservation areas

摘要: Habitat fragmentation is an important issue concerning species management and conservation. On the one hand, the basis for the study and decision making related to the outline of conservation areas comes in great part from island biogeography and metapopulation theories; however, the models derived from these theories generally ignore explicitly animal movement patterns. On the other hand, most research on movement ecology do not consider environments with a heterogeneous distribution of habitat. The aim of this study is to develop a model of animal movement in fragmented environments in order to answer the central question of the SLOSS problem: is a single large habitat patch more efficient than several small ones? The model assumes the animals follow truncated Lévy walks and search for circular habitat patches. The total habitat area remains constant and the number of patches is changed. While traveling among patches, there is a probability of dying that depends on the distance traveled; after finding a patch, an animal stays in its interior for a time proportional to its area. By counting the number of individuals that survive until a time T over many simulations, we aim at finding optimum search strategies in each configuration of habitat fragmentation.