Olfactory discrimination in scat-piling lizards

Several lizard species in the Australian scincid genus <it>Egernia</it> have been reported to deposit scats in piles. We show that <it>E. striolata</it>, which does produce scat piles, and <it>E. inornata</it>, which does not, can both discriminate their own secretions, on paper substrates, from those of unfamiliar conspecifics. This was indicated by elevated tongue flick rates and more time in contact with the unfamiliar stimulus. This was not just a response to a novel stimulus because the secretions from another species (<it>E. stokesii</it>) elicited lower responses. When scats were presented, only <it>striolata</it> demonstrated discrimination between their own scats and those of unfamiliar conspecifics. This suggests that scats could be used to produce individual signals, perhaps indicating residence status, in scat-piling species. For <it>striolata</it> the signal from scats became less effective as the scats became older, suggesting the need to pile scats to renew the signal.