Chemosensory discrimination of social cues mediates space use in snakes, Cryptophis nigrescens (Elapidae)

Snakes have traditionally been viewed as solitary, asocial animals whose habitat use is driven by temperature, prey and predators. However, recent studies suggest that snake spatial ecology may also be socially mediated. We examined the influence of conspecific chemical cues on refuge selection in a small nocturnal snake (the small-eyed snake) that engages in male contest competition. Females preferred refuges containing scent cues from conspecifics (of either sex) rather than scentless refuges. Males preferred female-scented rather than male-scented refuges, and preferred the scent of larger (and hence, more fecund) females than smaller females. Males spent more time in refuges containing the scent of smaller rather than larger males, but males that lost a contest did not avoid the refuge scented by the winner and therefore did not show evidence of the winner-loser effect. Females preferred refuges scented by larger males. Small-eyed snakes can distinguish conspecific sex and body size using chemical cues, and they use these cues to select alternative refuge sites. We suggest that social factors play a significant role in driving snake spatial distribution patterns in the wild and that snakes may exhibit more complex social systems than has generally been believed. © 2013 The Association for the Study of Animal Behaviour