Benefits of female mimicry in snakes

Males of several animal species mimic females either in appearance or in the chemical cues they release^1,2, and this mimicry has generally been interpreted in terms of alternative mating strategies –– for example, a male that mimics a female may obtain stolen inseminations or avoid aggression from larger rivals³. Our studies of snakes suggest a different explanation, which relies on natural selection rather than sexual selection. Male garter snakes that produce female-like pheromones (she-males) may benefit simply because large 'mating balls' of amorous males form around them, transferring heat to the she-male after it emerges from hibernation and reducing its exposure to predators.