Rostratula australis has been recorded in wetlands in all states of Australia. It is more common in eastern Australia, where it has been recorded at scattered locations throughout much of Queensland, New South Wales, Victoria and south-eastern South Australia (C. Jones in litt. 2009). The Murray-Darling Basin appears to be a particular stronghold (Thomas et al. 2010). It has been recorded less frequently at a smaller number of more scattered locations farther west in South Australia, the Northern Territory and Western Australia (C. Jones in litt. 2009). However, the relevant importance of northern and southern habitats are still subject to debate (S. Garnett in litt. 2009). The population was previously thought to number 5,000 individuals, though it is now believed highly unlikely that the population exceeds 2,500 and it may number between 1,000 and 1,500 individuals (S. Garnett in litt. 2009). Analysis of data from Birds Australia confirms that the species has been in decline. Although the precise rate is difficult to establish due to different survey methods, the cryptic nature of the species, and the lack of extensive surveys in the arid zone of northern Australia, a population decline of >30% is estimated for the past 26 years (3 generations) (Garnett et al. 2011).