Aspects of Social-Behavior and Dominance in Male Rainbow Skinks, Carlia-Rostralis

Abstract

A laboratory study was conducted to observe patterns of social behaviour of males of the sexually dimorphic rainbow skink, Carlia rostralis. Animals were observed alone or in matched pairs, both as residents and non-residents of the testing cage. Behavioural patterns observed included active, aggressive, submissive, assertive, exploratory and escape categories of acts. These patterns of behaviour varied in social contexts. Active behaviour increased significantly when males were paired. Of the paired encounters, 60% had neutral outcomes in which no dominant/subordinate individual could be determined. When dominance/subordinance interactions occurred they were found to be expressed in a linear hierarchy. Dominance was positively correlated with male snout-vent length. Dominance of males was absolute and did not depend on residence status. These observations of social behaviour in the laboratory, together with preliminary observations of behaviour of this species in the field, suggest that Carlia rostralis exhibits different patterns of social behaviour from that observed in other scincid lizards.