PHEROMONAL MEDIATION OF TRAILING BEHAVIOUR IN GARTERSNAKES (GENUS: THAMNOPHIS)

Michael P. LeMaster and Robert T. Mason
Dept. of Zoology, Oregon State University, Corvallis, OR 97331, USA.

The ability of many animals to successfully migrate between distantlocations plays a critical role in their survival. One navigational mechanismutilised by many organisms, particularly reptiles, is the trailing of chemicalcues laid down by conspecifics. The red-sided garter snake (Thamnophissirtalis parietalis) of Manitoba, Canada, provides an ideal systemfor studying trailing behaviour. These snakes exhibit a seasonal patternof migration between summer feeding grounds and winter hibernacula. Previousstudies have shown that snakes will trail conspecifics in the laboratorybut it has yet to be shown whether garter snakes will trail conspecificsin the field under natural conditions. To test whether garter snakes willtrail conspecifics under natural conditions, male and female red-sidedgarter snakes were caught in the field near Narcisse, Manitoba, duringthe spring migration and tested on a Y-maze. Trailing was observed to occurunder natural conditions. The role of a previously described female sexpheromone of the red-sided garter snake functioning as a trailing pheromonewill be addressed.