Macroderma gigasAustralian false vampire bat(Also: ghost bat)

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Geographic Range

Macroderma gigas or the Ghost Bat is found in Northern Australia where it has a scattered distribution. It is found north of 29°S in Western Australia, Northern Territories, and Queensland.

(Ride 1970, Strahan 1983)

Habitat

Ghost Bats have been recorded in both arid regions (Pilbara region) and rainforest areas (north Queensland). Macroderma gigas roost in caves, old mine tunnels and in deep cracks in rocks. They usually roost in colonies but, because many of their roosting sites are being destroyed, it is rare to find large colonies. Ghost Bats are distributed widely but patchily across the northern half of Australia and are found in a variety of tropical habitats. Perhaps the species' most famous roosting and nesting sites, and largest colonies, are at Mount Etna caves, near Rockhampton in Queensland.

(Nowak 1991, Ride 1970, Strahan 1983)

Physical Description

SIZE: Head and body length is 10 to 13cm and forearm length is 10.2 to 11.2cm. Females are smaller than males.

WEIGHT: 130 to 170 grams.

Ghost Bats have a light grey, almost white, appearance and large long ears that are joined at the base. The head and body measure up to 130 mm with a wingspan of about 500 mm.

In the Pilbara district of Western Australia, Ghost Bats are of the pale 'ghostly' desert form with ashy-grey back and white under-parts. Juveniles are sooty-grey all over. In the northern part of their range, especially in Kimberley, Arnhem Land, and around Rockhampton in Queensland, adult Ghost Bats are a dark sooty-grey.

(Nowak 1991, Ride 1970, Strahan 1983)

  • Range mass
    130 to 170 g
    4.58 to 5.99 oz
  • Range length
    115 to 130 mm
    4.53 to 5.12 in
  • Average length
    127.50 mm
    5.02 in
  • Average wingspan
    500 mm
    19.69 in
  • Average basal metabolic rate
    0.639 W
    AnAge

Reproduction

Little is known about mating in ghost bats.

Mating takes place in July and August. Gestation lasts about three months and females bear a single young between September and November. Sexual maturity is attained in the second year of life. (Nowak, 1991, Ride 1970, Strahan 1983)

  • Breeding season
    Mating takes place in July and August, births occur from September to November.
  • Range number of offspring
    1 (low)
  • Average number of offspring
    1
  • Average number of offspring
    1
    AnAge
  • Average gestation period
    3 months
  • Average weaning age
    3 months
  • Average age at sexual or reproductive maturity (female)
    1 years
  • Average age at sexual or reproductive maturity (male)
    1 years

Mothers form nursery colonies separate from the males while the young are being weaned. While the young are still suckling, they are left in the roost while the females go out to hunt. Juveniles then hunt with their mothers until they become completely independent. Young begin flying at 7 weeks and become weaned by the March following their birth. (Ride 1970, Strahan 1983)

Lifespan/Longevity

Information on lifespan in this species is lacking.

  • Average lifespan
    Status: captivity
    22.6 years
    AnAge

Behavior

Macroderma gigas are secretive and, being exclusively cave-dwelling, are so unobtrusive that human residents, even miners who enter the tunnels in which they occur, will claim to know of the presence of other bats but not M. gigas.

These bats roost alone or in small groups, though larger colonies occur seasonally. Sexes become largely segregated to different colonies during the birthing season and before young are weaned.

(Nowak, 1991, Ride 1970)

Communication and Perception

Food Habits

Macroderma gigas is Australia's only carnivorous bat, eating large insects, reptiles, frogs, birds, small mammals, and sometimes other bat species. Much of this prey is captured on the ground. Ghost Bats drop on mammals from above, enveloping them with their flight membranes, and kill them with bites about the head and neck. They eat large amounts of food including flesh, bones, teeth, fur, small feathers, and the chitinous exoskeletons of insects. Ghost Bats appear to need this roughage in their diet because if they are fed on boneless meat in captivity they soon become distressed and fouled with loose excreta.

(Ride 1970)

  • Animal Foods
  • birds
  • mammals
  • amphibians
  • reptiles
  • insects

Predation

Ghost bats have few natural predators, though larger owls may take them at night and young may fall prey to roost predators, such as snakes. Medium-sized owls compete for insects and small mammals.

(Nowak 1991)

Ecosystem Roles

Ghost bats are important predators of small mammals, birds, and reptiles in the areas in which they live.

Economic Importance for Humans: Positive

Ghost bats are important in the control of rodents, especially introduced house mice, and other small mammals. They also produce guano, which can be used as a fertilizer.

  • Positive Impacts
  • produces fertilizer
  • controls pest population

Economic Importance for Humans: Negative

There are no significant negative effects of ghost bats.

Conservation Status

Ghost Bats are sensitive to disturbance. Human intruders to a cave colony may cause the group to become nervous and leave. Many roost caves have been destroyed or are threatened by mining activity. Disturbance and loss of roosting sites due to mining, tourism and internal dereliction of mines through aging of timber supports are known threats. In recent times population declines could be attributable to competition for prey with feral cats, and prey lost through habitat modification by fire and livestock

Ghost Bats are protected by national legislation in Australia.

(UNEP 2001)

Contributors

Justin Cooper (author), University of Wisconsin-Stevens Point, Chris Yahnke (editor), University of Wisconsin-Stevens Point.

Glossary

Australian

Living in Australia, New Zealand, Tasmania, New Guinea and associated islands.

World Map

altricial

young are born in a relatively underdeveloped state; they are unable to feed or care for themselves or locomote independently for a period of time after birth/hatching. In birds, naked and helpless after hatching.

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

carnivore

an animal that mainly eats meat

chemical

uses smells or other chemicals to communicate

endothermic

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

female parental care

parental care is carried out by females

fertilization

union of egg and spermatozoan

forest

forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.

insectivore

An animal that eats mainly insects or spiders.

internal fertilization

fertilization takes place within the female's body

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

motile

having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.

nocturnal

active during the night

rainforest

rainforests, both temperate and tropical, are dominated by trees often forming a closed canopy with little light reaching the ground. Epiphytes and climbing plants are also abundant. Precipitation is typically not limiting, but may be somewhat seasonal.

scrub forest

scrub forests develop in areas that experience dry seasons.

seasonal breeding

breeding is confined to a particular season

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

social

associates with others of its species; forms social groups.

tactile

uses touch to communicate

terrestrial

Living on the ground.

tropical

the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.

viviparous

reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.

References

1 October 2001. "UNEP World Conservation Monitoring Centre" (On-line). Accessed 27 October 2001 at http://www.unep-wcmc.org/species/data/species_sheets/ghostbat.htm.

1 September 2001. "Welcome to Perth Zoo" (On-line). Accessed 27 October 2001 at http://www.perthzoo.wa.gov.au/ghostbat.html.

Nowak, R. 1991. *Walker's Mammals of the World, 5th ed., Vol I*. London: John Hopkins University Press.

Ride, W. 1970. *A Guide to the Native Mammals of Australia*. Melbourne: Oxford University Press.

Strahan, R. 1983. *The Australian Museum Complete Book of Australian Mammals*. London: Angus & Robertson Publishers.

Thornback, J., M. Jenkins. 1982. *The IUCN Mammal Red Data Book, Part 1*. Gland.: IUCN.