The Southern Bent-wing Bat is an insectivorous, obligate cave-dwelling bat. It has dark reddishbrown to dark-brown fur on the back, grey-brown fur underneath and pale brown areas of bare skin. It has a distinctive short muzzle, a high crowned/domed head and small eyes. The ears are short, rounded and roughly triangular. The second phalanx on the third finger of the wing is about four times the length of the first phalanx, giving the typical ‘bent wing’ appearance. The Southern Bent-wing Bat has a mean weight of 15.7 g, head and body length of 52–58 mm, and forearm length of 45–49 mm. While the Southern Bent-wing Bat is, on average, slightly larger than the other two subspecies of Large Bent-wing Bat, the three subspecies are morphologically very similar. The distribution of the Southern Bent-wing Bat and the Eastern Bent-wing Bat overlap in western Victoria, and individuals of each subspecies may roost together in some non-maternity caves. Currently, these two subspecies cannot be reliably distinguished using traditional field-based techniques.
Southern Bent-wing Bat |
Miniopterus orianae bassanii
Status: Critically Endangered on the EPBC Act list
Government evidence of impact of climate change:
Australian Government, Conservation Advice, Miniopterus orianae bassanii
In particular; the lower survival rate recorded in the drought year provides valuable information that can be used to model the impacts of increasing drought frequency under future climate change scenarios.
Increased storm frequency due to climate change may exacerbate the rate of collapse (DELWP 2020).
Periods of low rainfall are likely to increase under ongoing climate change (Grose et al. 2015 Timbal et al. 2015).
Under future climate change scenarios; the frequency and severity of droughts are likely to increase (Grose et al. 2015 Timbal et al. 2015); placing increasing pressure on populations.
There is a projected continuing decline in the EOO; number of mature individuals; and extent quality of foraging habitat due to likely impacts from climate change and disease (as outlined under Criterion 1).
Fire Severe bushfire Potential The impact of fire on bats is not well understood.
Fire could directly impact roosting bats if smoke was drawn into the caves; and foraging habitat and prey availability could be negatively affected (DELWP 2020).
Drought has severely impacted Southern Bent wing Bat populations in the past (E. van Harten pers. comm. 2020).
Models were run using the new information on survival rates and female reproduction rates together with the frequency and effects of both drought and WNS.
Two models were run a conservative model that used the higher survival rates and lower impacts of drought and WNS; and a less conservative model that used the lower survival rates and higher impact levels from drought and WNS (for details see Appendix 1).