Southern Grass skinks are found in a variety of habitats where they tend to forage amongst dense ground cover or grasses and bask on rocks and logs. It is a member of a group of very similar skinks and identification can be difficult.
A highly variable species in both colour and pattern, the Southern Grass skink is difficult to distinguish from other closely related members of the genus Pseudemoia occurring in Tasmania. The pattern is sometimes similar to the superficially similar Three-lined skink, but the Southern Grass and Tussock skinks have relatively longer limbs and the frontoparietals are paired. In western and highland populations Southern Grass skinks tend to be much more strongly striped but are the only members of this group occurring in these areas. While the dorsal colour is usually a uniform dark brown, dorsal colouration ranges from light brown to almost black above.
This species usually has a dark mid-vertebral stripe and a dark dorso-lateral stripe sometimes edged in white. Southern Grass skinks lack the glossy sheen of other members of this group. The belly, throat and forward portion of the lower lateral stripe becomes flushed with red or orange in breeding males. (Male Tussock skinks only have orange or red on the lateral stripe). The transparent disk in the lower eyelid is so large the whole eye can be seen when the eyelid is closed. Tasmanian specimens achieve a larger size than their mainland counterparts, reaching about 63 mm in head and body length.
Southern Grass skinks are widely distributed in Tasmania and occupy a variety of habitats from sea level to about 1000 m. They occur in low to tall open forest, woodland, heathland, and alpine herbfields, most commonly associated with open grassy woodlands. The Southern Grass skink is a fairly able climber and tends to utilise rocks and logs for basking and shelter far more than its close relatives, the Tussock skink and Glossy Grass skink.
The species mates in autumn, storing sperm over winter and ovulating in the spring. Two to nine young are born in late February and mating for the following season takes place shortly after. This species has a highly developed placenta with nutrients being passed to the developing embryo early in development.
Widespread throughout Tasmania except the higher peaks and in heavily forested areas. Southern Grass skinks also occur on some offshore islands including Clarke Is., Fisher Is., Flinders Is., Hunter Is., King Is., Maria Is., Preservation Is., Schouten Island and Vansittart Island. This species is also found in S.A, Victoria and N.S.W.
The destruction of native grasslands has removed a lot of available habitat for this species. Southern Grass skinks are preyed on by cats and Laughing Kookaburras.