Long considered to comprise southern populations of the stuttering frog (M. balbus), it was not recognised as a new species until 2023, when a phylogenetic study found it to be deeply divergent from M. balbus and thus described it as a new species.[2] The distributions of the northern and southern stuttering frogs are separated by the Macleay River.[3]
This species has disappeared from two-thirds of its distribution, and thus qualifies for Endangered on the IUCN Red List.[4][5] Populations south of Sydney have declined dramatically and the Victorian populations are believed to be extinct, although northern populations are thought to be stable. Unlike M. balbus, which is a high-altitude specialist, both upland and lowland populations of M. australis have been recorded.[2]
