Print PageMigration is a widely used strategy for dealing with a seasonally variable environment. It has long been accepted that migration should only occur when it is advantageous, and that the costs and benefits of migrating depend on ecological conditions. However, the question of what specific types of ecological conditions select for migration remains unresolved. This is due in part to the fact that, most discussion of migration occurs at the species level and little work has been done to understand migration as a general phenomenon. This narrow scope fails to address underlying cross-taxa commonalities, such as 'What are the ultimate factors that drive migration?’. We have developed a spatially-explicit, individual-based model in which we can evolve behavior rules via simulations under a wide range of ecological conditions to answer two questions. First, under what types of ecological conditions can an individual maximize its fitness by migrating (versus being a resident)? Second, what types of information (local, historical, or social) do individuals use to guide their movement?
Results/Conclusions
We show that certain ecological conditions (in terms of seasonality and patchiness of resources and survival) select for migration, whereas other conditions select for residency, or non-migratory behavior, and that there is often a sudden switch between residency and migratory behavior. When selected for, migration evolves as both a movement behavior and an information-usage strategy. We also find that different types of migration can evolve, depending on the ecological conditions and availability and cost of information. Finally, we discuss these results in the context of patterns of animal migration that have been observed across different groups of species.
