The vomeronasal organ VNO is important for activating accessory olfactory pathways that are involved in sexually dimorphic mating behavior. The VNO of male garter snakes is critically important for detection of, and response to, female sex pheromones. In the present study, under voltage-clamp conditions, male snake VNO neurons were stimulated with female sexual attractiveness pheromone. The amplitude of the inward current was dose dependent, and the relationship could be fitted by the Hill equation. Under current-clamp conditions, application of pheromone produced membrane depolarizing responses and increases in firing frequency. These results suggest that the female pheromone directly affects male snake VNO neurons and results in opening of ion channels, thereby converting the pheromone signal to an electrical signal.
With their sinuous bodies, sharp fangs and, sometimes, potent venom, snakes have long struck fear into the hearts of humans and our primate ancestors. But when it comes to mating, do these ancient reptiles also have a softer side? Though snakes garner much media and research attention, the reproductive strategies of many species are still shrouded in mystery. Unlike most other snakes, the mating behaviors of garter snakes have been extensively studied.
Variation in a Female Sexual Attractiveness Pheromone Controls Male Mate Choice in Garter Snakes
Male red-sided garter snakes Thamnophis sirtalis parietalis display a courtship preference for larger females during the breeding season. When presented with skin lipid extracts from large and small females, a greater proportion of males displayed courtship behaviors to large female extracts. This demonstrates that there is an intrinsic property of the female skin lipids that allows males to differentiate among large and small females.
The problem is that it's not as simple to find out if a snake is male or female as it is in many other animals. On the outside, male and female snakes look similar. However, with a bit of experience, there are ways to differentiate between the two. The following methods of sexing snakes should only be done by experienced caretakers or veterinary staff.