Digest: Exploring the interplay between migration and speciation in the barn swallow .

When members of the same population follow distinct migration routes, a migratory divide can arise. Could differences in migratory strategies contribute to genetic differentiation and possibly speciation? In this study, Turbek et al. combine genomic data, stable isotopes, and geolocators to characterize a migratory divide between two subspecies of the barn swallow (Hirundo rustica). Their findings set the stage for further analyses into the genetic basis of migratory behavior.