The use of movement to communicate is widespread in the animal kingdom, and understanding of the structure and function of signals defined by movement has benefited from the study of lizards. Many species exchange signals during territorial disputes in order to assess relative status from a distance and avoid physical combat where possible. Some members of the Scincidae family of lizards (skinks) are known to produce very conspicuous motion-based displays, but are rarely formally studied. Rainbow skinks (genus Carlia) are small terrestrial lizards often found among the leaf litter in dry forests, woodlands, and rainforests in north east Australia. Males usually develop bright colouration during the breeding season, which they use to signal status. Additionally, many Carlia species have been previously observed waving their tail while they move about their environment, but the function of this behaviour remains unknown. In the only study of this behaviour in this group, Langkilde, Schwarzkopf & Alford (2004) demonstrated that, in males, this behaviour is elicited in a variety of circumstances including when alone, in the presence of male and female conspecifics, and in the presence of a predator model. However, detailed examination of signal structure was not undertaken, and the signalling behaviour of females were not investigated. We will expand on this study by employing quantitative techniques to measure signal structure for several species of Carlia.
