Thermal regulation of spring mating behavior in the red-sided garter snake (Thamnophis sirtalis parietalis)

Exposure of Thamnophis sirtalis parietalis to elevated temperatures immediately after emergence from hibernation induced intense mating behavior. The thermal threshold for courtship varied widely among individuals, and ranged from below 5 °C to between 20° and 25 °C. The lowest temperature at which copulation occurred was 10 °C. Both courtship and copulation increased with increasing temperature, and reached maximal levels at 25° and 30 °C respectively. The existence of low thermal thresholds for mating behavior and the marked stimulating effect of temperature on mating behavior explain the rapid onset of courtship and copulation after emergence from hibernation. A possible mechanism for thermal induction of mating behavior is discussed.