Recent Physical Encounters Affect Chemically Mediated Retreat-Site Selection in a Gecko


Sharon Downes, Australian Cotton Research Institute, Locked Bag 59, Narrabri 2390 NSW.


Chemoreception is well documented in a range of animals but the effects of recent behavioural interactions on an animal's response to subsequent chemical information are poorly understood. Using a series of laboratory experiments with a rock-dwelling gecko (Oedura lesueurii), we examined whether latest social experience affects how animals used chemoreception to mediate microhabitat selection. Males of this species defend retreat-sites and the outcomes of physical duels are maintained during second physical contests staged up to 1 wk after first contests. Retreat-site selection experiments showed that past social experience affects the behavioural responses of adult male geckos to chemical cues from conspecific male lizards. When offered a choice between retreat-sites labelled with chemicals from an unknown male vs. the opponent from a recent contest, geckos that won their previous fight selected retreat-sites at random. In contrast, under the same conditions, geckos that lost their previous fight significantly preferred retreat-sites scented with an unknown male conspecific over those scented with the winning opponent. During these experiments males that lost their previous fight were significantly more vigilant, and spent greater time near the retreat-site of the unknown male, compared with males that won their previous fight. These results support the notion that recent physical social encounters can affect the way that animals respond to chemical information from potential competitors.