Ghost bat

Ghost bat Photo: Bruce Thomson

Common name: ghost bat

Scientific name: Macroderma gigas

Family: Megadermatidae

Conservation status: This species is listed as Vulnerable in Queensland (Nature Conservation Act 1992). It is ranked as a critical priority under the Department of Environment and Resource Management Back on Track species prioritisation framework.

Description

This species is the largest of the micro-bat family in Australia. This bat is readily identifiable by its size, either in flight or in the hand. Ghost bats have a body length of 98-118 mm and a body weight of 74-144 g. Other distinct features of this species are its very large ears, which are joined above the head, and the light coloured fur and wing membranes. The fur colour varies from pale grey or light brown to almost white with increasing distance from the coastline. This species also has relatively large eyes, a long, simple noseleaf, and no tail.

Habitat and distribution

Ghost bats occur in a wide range of habitats from rainforest, monsoon and vine scrub, to open woodlands in arid areas. These habitats are used for foraging, while roost habitat is more specific. When foraging they use perches which are less than three metres above the ground, on small branches or the main trunk of eucalypts.

Ghost bats occur in tropical regions in Queensland, Northern Territory and Western Australia. The distribution of this species does not extend far inland, as it has in the recent past. In Queensland, ghost bats occur along the central and northern coast, from Rockhampton north to Cape York.

Life history and behaviour

Ghost bats are nocturnal, hunting prey such as birds and small mammals and capturing insects from the air. This species does not forage only during flight, but often scans for prey from vantage points up to three metres above the ground. When prey is detected, it is captured on short flights and consumed at the original perch. Less palatable portions of the prey are dropped to the ground.

Prey is detected by using echolocation, vision, or hearing (without echolocation). Their echolocation call is of low intensity, making it difficult to detect with a bat detector. Ghost bats make distinctive twitters and chirps in the roost and during foraging, which can indicate their presence in the forest at night. This species is remarkably quiet and still when in the hand. They appear highly sensitive to disturbance; the approach of humans can cause desertion from foraging areas.

Threatening processes

Known threats to the ghost bat are disturbance to roost sites from mining operations, collapse of old mines, or human disturbance. Also suspected as threats, are reduction in prey populations related to predation from cats and foxes, or changed fire regimes.

Recovery actions

Prevent further disturbance to roost sites from mining activities and unnecessary human visits to roosts.
Prevent further degradation of roosts in mines by reinforcement, or replacement of rotting timbers only outside of the breeding season.
Clarify the status of the arid zone regional populations with genetic analysis.

Further information

Churchill, S 1998. Australian bats. New Holland, Sydney.

Duncan, A, Baker, GB and Montgomery, N (Eds.) 1999. The Action Plan for Australian Bats. Environment Australia, Canberra.

Menkhorst, P and Knight, F 2001. A field guide to mammals of Australia. Oxford University Press, Melbourne, Victoria.

Strahan, R 1995. The Mammals of Australia. Revised Edition. Australian Museum and Reed New Holland publishers.

Last updated 14 July 2011