Abstract
Gonadal steroids have traditionally been found to have short-term effects on the mating behavior of adult vertebrates, such that increased steroid hormone levels influence behavior over the course of a few days. Long-term effects also have been observed in which embryonic exposure to steroid hormone influences the sexual behavior of adults. The generality of the paradigms that have resulted from this work must be viewed with caution as all of the species studied exhibit a particular reproductive pattern. Here it is shown that in the adult red-sided garter snake, the seasonal androgen peak in the summer has a delayed action (8 months) on the male's readiness to court the next spring following emergence from hibernation. This suggests that the interval between the exposure to and the effects of steroid hormones in adult vertebrates may range from short latencies to long latencies and that the present dichotomy of organizing (permanent) versus activating (transient) effects of steroid hormones may not apply in certain instances.