Pseudomys australis

The primary extant population of the plains rat can be divided into five broad geographic zones: 1) the Arcoona Tableland, SA; 2) the Southern Lake Eyre region, SA; 3) the Moon Plain region, SA; 4) the Oodnadatta region (including Witjira National Park), SA/NT; and, 5) the Andado Station and Mac Clark Conservation Reserve, NT. These areas are characterised by access to boulders, small stones and gilgais (depressions and water soaks) and are consistent with the plain rat's primary habitat type of stone-covered plains. Historically, the plains rat was widely distributed across a broad range of habitats including river flats, grasslands, sand ridges and lowland shrubs; however, the current assumed distribution of the plains rat is limited to the gibber (stone-covered) plains in central-northern South-Australia. These areas are characterised by cracking clay, productive depressions and minor drainage lines which support low open scrublands and ephemeral grass or herb lands. While an individual's home range is roughly 1.6 hectares, colonies may extend beyond their preferred habitat type in search of drought refuges, essentially increasing their home range. These refuges are usually areas of higher shelter and food availability with more productive vegetation types. …

The plains rat constructs a complex system of shallow connected tunnels beneath the cracking clay of gibber plains, emerging only at night to feed on seeds, stems and arthropods. The home range of an adult is roughly 1.6 hectares. During non-breeding periods both sexes live together in colonies of up to 20 individuals; however, during breeding periods one male occupies a burrow with up to three females. During breeding cycles males becoming increasingly agitated and both sexes are known to stand on their hind feet and squeal loudly when threatened. Whilst breeding is not regularly seasonal, young is generally produced after sexual maturity is reached at 8–10 weeks and after a gestation period of 30–31 days. Litter sizes usually consist of four young but up to seven young can be produced in one litter. The lifespan of the plains rat is generally two years; however, their survival often depends on resource availability. Thus, during years of consecutively high rainfall, their lifespan can approach 4.5 years. Similarly, during severe drought most will only survive one year.