Southern and inland extension of range for the Little Bent-winged Bat Miniopterus australis in New South Wales from 1981 to 2022

Much of our knowledge of the distribution and behaviour of the Little Bent-winged Bat Miniopterus australis in New South Wales is derived from papers published in the 1960s. Available records of M. australis were collated from BioNet Atlas of NSW, as well as the personal database of GH, and analysed to examine evidence for an extension in range over the past 41 years. Records of this bat were found to have progressively moved southwards and to a lesser extent inland within New South Wales since 1980. This was the case for both records derived from echolocation call detection (1992-2022), as well as physical records from trapping, roost inspections and individuals coming into wildlife care groups (1980-2022). When shifts in sampling effort are accounted for, only echolocation data demonstrate a range extension south over the period 1996-2022. The extent of movement varied somewhat between the two groups of records and this was attributed to changes in survey methodologies over the decades from 1980. Additional evidence of an extension of range inland was obtained by the capture of individuals at two sites where repeated survey had failed to reveal the presence of this species previously. While climate change is a likely contributor to colonisation of new areas by this cave-roosting insectivorous bat, other factors may have contributed including disturbance due to guano mining and inappropriate human cave visitation across the network of cave roosting sites used by this species. In particular, guano mining of its only known breeding site in NSW may mean that what we see as expansion now is simply recolonisation of previously occupied areas.