Kira E. Delmore and Darren E. Irwin published a paper this week in Ecology Letters. They attached light-level geolocators to birds breeding in a hybrid zone between Swainson’s thrushes in western Canada. They provide the first direct test of the hypothesis that contact zones between populations use different routes to navigate around unsuitable areas on seasonal migration. They found support for this as well as Hybrids also tended to use geographically intermediate wintering sites.
Stanly et al (2014 Conservation Biology) attached over 100 geolocators to Wood Thursh across their breeding range. “We identified regional and species-level migratory connectivity networks for this declining songbird by combining our tracking results with range-wide breeding abundance estimates and forest cover data.”