Facultative pheromonal mimicry in snakes: "she-males" attract courtship only when it is useful

• Published in: Behavioral ecology and sociobiology Vol. 66; no. 5; pp. 691 - 695
• Main Authors: Shine, R., Langkilde, T., Mason, R. T.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer 01.05.2012; Springer-Verlag; Springer Nature B.V
• Subjects: Animal behavior; Animal Ecology; Animal mimicry; Behavioral biology; Behavioral Sciences; Biomedical and Life Sciences; Body temperature; Chemosensory perception; Female animals; Garters; Ketones; Life Sciences; Lipids; Male animals; Mating behavior; Mimicry; Original Paper; Pheromones; Snakes; Thamnophis sirtalis parietalis; Zoology; Chemical communication; Reproductive tactics; Sexual mimicry; Reptile sociality
• ISSN: 0340-5443; 1432-0762
• DOI: 10.1007/s00265-012-1317-4

Males of many animal species mimic females, and thereby deceive rival males. Facultative shifts in posture, color, or movement allow a male using visually-based mimicry to adopt and terminate mimicry rapidly. Pheromonal mimicry is rare in vertebrates perhaps because it is difficult to redeploy pheromones rapidly enough to adjust male tactics to local conditions. In Manitoba garter snakes (Thamnophis sirtalis parietalis), female mimicry benefits males immediately after they have emerged from hibernation. While the snakes are cold and slow, courtship warms them and protects them against predatory crows. This benefit disappears as soon as the snakes are warm. We show that (unlike females) she-male garter snakes attract courting males only when they are cold. Low temperatures may suppress volatility of "less attractive" components of the pheromones (saturated methyl ketones) that she-males use to attract courtship, allowing male snakes to function as transvestites only when this tactic is beneficial.