White-striped freetail bat in Tasmania – resident, vagrant or climate change migrant?

The white-striped freetail bat (Austronomus australis) is distributed throughout mainland Australia, but historically has not been known from the island of Tasmania, off south-eastern mainland Australia. Between 2009 and 2012, echolocation calls identified as those of A. australis were recorded in Tasmania during bat call surveys. There are three hypotheses that could explain the discovery of this species in Tasmania: that A. australis is a previously undetected resident; it is a vagrant; or it is undergoing a southwards range expansion or shift. Based on the limited evidence available, including this species’ long-range flight capabilities (including over open water out to sea), I suggest that this species is a periodic vagrant to Tasmania and that monitoring is necessary to identify whether this species is undergoing a southwards range extension into Tasmania.