Miniopterus shreibersii oceanensis

Conservation Status

Vulnerable species in New South Wales (Threatened Species Conservation Act). Classified as ‘lower risk (least concern)’ at national level.

What does it look like? The Eastern Bent-wing Bat has chocolate to reddish-brown fur on its back and slightly lighter coloured fur on its belly. It has a short snout and a high ‘domed’ head with short round ears. The wing membranes attach to the ankle, not to the base of the toe. The last bone of the third finger is much longer than the other finger-bones giving the “bent-wing” appearance. It weighs up to 20 grams, has a head and body length of about 6 cm and a wingspan of 30-35cm. (from DEC NSW Threatened Species Profile)

Where does it live?

They are found along the east coast of Australia from Cape York in North Queensland to Castlemaine in Victoria. They predominantly occur east of the Great Dividing Range. Numerous records exist for Pittwater from 1996 in the following suburbs:

• Ingleside
• Angophora Reserve
• Avalon
• McKay Reserve
• Elanora Heights
• Bayview
• Church Point
• Bilgola Plateau
• Deep Creek
• Bayview Woods

There is a regular occurrence in St Michaels Cave at Avalon. This is an important roosting site for the Sydney region but it is unlikely to be used as a nursery cave.

They occupy a wide range of habitats including wet and dry sclerophyll forest, open woodland, paperbark forest, rainforests and grasslands, but it is typically found in well-timbered valleys. The chief habitat requirements for this species are suitable roosting and breeding sites. These are found in caves, mines, stormwater pipes, road culverts and similar sites, even sometimes in buildings. Colonies vary greatly in size. Some are dominated by males, others by females; some consist mainly of adults, others mostly young.

What do they eat?

The Eastern Bent-wing bats fly level and fast, making rapid shallow dives for flying insects above the vegetation canopy. They can lay down fat reserves before winter and in many areas feeding virtually ceases during the coldest months, possibly because of a scarcity of insects. The main dietary item is believed to be moths.

What is their life cycle?

In winter, bats enter periods of torpor, by allowing their body temperature to reduce to almost that of the air temperature within the roost. Breathing and heart rate are lowered saving a significant amount of energy.

In NSW mating occurs in the winter roosts between May and early June, prior to entering torpor. Delayed implantation occurs and development of the young does not commence until late August. Females leave in September/October to travel to a suitable maternity cave to give birth and raise young. These maternity caves are of a more specific nature than normal roosting sites, being characterised by high temperature and humidity throughout the year or being shaped such that the air warmed by the bats’ activities is retained within the cave while the colony is present. Such caves are of critical importance for the survival of the species at a regional level. Nursery colonies disband between February and March, adults and juveniles going separate ways, with some juveniles dispersing many hundreds of kilometres at this time. One individual was recorded moving 1300km! Sexual maturity is reached in their second year and they can live to over 17 years.

What are the threats?

• Redevelopment of urban areas (loss of roosts and foraging sites)
• High Injury Rate – caused by vehicle accidents, human disturbance at roosts, cat predation, flooding in stormwater drains and culverts.

Updated: 20 Jul 2011