Animals living in different areas or habitats encounter different selection pressures on their physical and behavioral traits. Studies of such geographic variation must incorporate both genetic and historical information to be most informative. In this study, geographic variation in antipredator behavior will be examined in common gartersnakes (Thamnophis sirtalis) living in an island system with a well-documented geological history. The influence of predator pressures and various genetic characteristics on geographic variation in behavior will be examined in adult and neonatal snakes from several island and mainland populations, testing a series of hypotheses relating the differences in antipredator behaviors to predation pressures. Data collected to date indicate that both predator pressures and defensive behavior differ among these populations. Since the age of each island is known, the history of the island snakes will be reconstructed using molecular markers of genetic differentiation and measurements of the relative effects of genetic history and predation on the behavioral responses of the snakes. This study will be one of few that combines data on natural differences in complex behavior and genetics, providing much needed information on the divergence of behavior at the intraspecific level and the needs of conservation biology. In addition, this research utilizes undergraduates from several universities and provides training in behavioral and molecular biology.
