An ethogram for adult male rainbow skinks, Carlia jarnoldae

An ethogram for male rainbow skinks, Carliajarnoldae (mean snout-to-vent length 44 mm), was derived from observations of captive individuals in large, semi-natural field enclosures during the summer. Males were observed in one of four treatments: solitary, socially with a male conspecific, socially with a female conspecific, or with a model of an avian predator. We identified 32 different types of behaviour, including postures and simple movements. Six of the behaviours (dorsolateral orientation, head bob, letisimulation, slow motion, throat flash and tail wave) are of particular interest because their functions are either controversial or unknown. We describe them in detail, and infer their functional significance from the contexts in which they occurred. Dorsolateral orientation and slow motion behaviours appear to function primarily in courtship; throat flashes may provide information to conspecifics; and letisimulation may function as an antipredator behaviour. The function of head bobs remains unresolved, and tail waves appear to signal residency, but need further investigation. Although the behaviours exhibited by C. jarnoldae males were generally similar to those reported in other skinks, two of the behaviours we observed (letisimulation and throat flash) have not previously been recorded in a skink. Carliajarnoldae males were outside refugia for most of our observation periods, and appeared to defend areas of the enclosures from conspecific males. Both visual signals (dorsolateral orientations, slow-motion behaviour and throat flashes) and chemical cues were used to communicate with conspecifics.