Each year an estimated 10 billion land birds migrate between northern and southern latitudes in search of suitable habitat for breeding and over-wintering. Long distance migration is energetically costly and dangerous, creating the potential for strong natural selection on traits that ensure a successful journey. Migratory divides, defined as regions of contact between populations with distinct migratory pathways, provide a unique opportunity to examine how differences in migration behavior may reduce mating success between divergent migratory forms. This research will test the hypothesis that differences in migratory behavior across a migratory divide in the Swainson's Thrush (Catharus ustulatus) limits mating opportunities between distinct migratory forms.
The Swainson's thrush system will serve as a model for investigation of the importance of divergent migratory strategies to the process of diversification in other migratory organisms. The proposed research will investigate the importance of considering divergent migratory forms as evolutionarily distinct units for conservation planning and management. Interns from under-represented ethnic and gender groups have been and will continue to be integral component of the proposed research.