Mother–offspring recognition in two Australian lizards, Tiliqua rugosaand Egernia stokesii

Abstract

Abstract. Kin recognition has been reported in many animal taxa, but rarely in lizards. Newly born clutches from two viviparous Australian skink species, Tiliqua rugosaand Egernia stokesii, were either left with their mothers, separated at birth and kept with a foster mother, or kept completely isolated from any adults. In experimental trials mothers were presented with their own and with non-related young in gauze bags, and their attention to each young lizard was measured by the number of directed tongue flicks and the time in contact. There was a consistent tendency in both species for mothers to direct more attention to their own young, whether they had been kept together or apart. Foster mothers directed more attention to their own non-familiar young than to their familiar foster young. In reciprocal experiments, young lizards of both species consistently directed more attention to their own mothers than to unrelated females, even when they had been isolated from their mothers from birth. Olfactory cues are probably important for recognition. Using these cues, lizards can recognize kin,and discriminate between kin and non-kin even if the latter have been in close association. It wasnot possible to determine if the discrimination was genetically based, or if it was acquired during orshortly after birth. The presence of mother–offspring recognition suggests that family groups maybe a component in the social organization of these species.