Hormones and Reproductive Cycles in Snakes

The study of the hormonal regulation of reproduction in snakes is in its infancy. Studies have disproportionately examined temperate zone viperid and colubrid snakes, especially the red-sided garter snake (Thamnophis sirtalis parietalis). Indeed, extensive observational and experimental studies on T. s. parietalis form the basis for our understanding of the hormonal regulation of reproduction in snakes. This review focuses on seasonal hormone concentrations in snakes in relation to events in the reproductive cycle; the limited data available on hypothalamic hormones, gonadotropins (GTHs), hormone receptors, and binding globulins; the neuroendocrinology of reproduction; and the environmental, social, physiological, and embryonic aspects of hormonal regulation of reproduction in snakes. The review ends with suggestions for future research, including studies of a more diverse ecological and taxonomic representation of snakes, experimental studies on the effects of hormones on reproductive tissues and behaviors, and further research into the neuroendocrinology of reproduction in this highly diverse group of animals