The Role of Seasonal Migration in Population Divergence and Reproductive Isolation

Seasonal journeys between breeding and non-breeding habitat are undertaken by a diverse array of animals. Parallel developments in tracking and genomic methods are enabling finer resolution of these movements and their role in the evolutionary process. Evidence from allopatric and co-occurring breeding populations indicates that variation in migratory behavior is often associated with genetic differentiation. While assortative mating and selection against hybrids due to divergent migratory phenotypes can contribute to reproductive isolation, the details of these mechanisms remain unclear. Here we identify gaps in our understanding of the role of seasonal migration in the speciation process and propose a framework to test the relative significance of reproductive barriers associated with variation in migratory behavior that might underlie population differentiation.