False vampire bats

(Megadermatidae)

Class Mammalia

Order Chiroptera

Suborder Microchiroptera

Family Megadermatidae

Thumbnail description
The bifurcate tragus and the absence of upper incisor teeth make false vampire bats distinctive

Size
Medium-sized to large bats with forearms that range from 1.9–4.6 in (5–11.8 cm); 0.7–5.9 oz (20–170 g)

Number of genera, species
4 genera; 5 species

Habitat
From forest to open woodland and desert

Conservation status
Vulnerable: 1 species; Lower Risk/Near Threatened: 1 species

Distribution
Africa, Asia, through the East Indies into Australia

Evolution and systematics

False vampire bats belong to the superfamily Rhinolophoidea. They first appeared as fossils in Eocene deposits, but the fossil record is not extensive. No subfamilies are recognized.

Physical characteristics

Medium-sized to large bats with broad wings. False vampire bats have large ears, large eyes, and distinctive nose-leaves. Their long and silky fur tends to be gray in color. The bifurcate tragus and lack of upper incisors are diagnostic for the family.

Distribution

Megadermatids occur widely in Africa and from eastern Afghanistan through India and Sri Lanka, and on through Myanmar, southwestern China, Malaysia, and the East Indies (Java, Borneo, the Philippines, Bali, Sulawesi, Sangihe Islands, Togian Islands, Lombok, the Moluccas). They are also found in the Andaman Islands, as well as in parts of Australia.

Habitat

False vampire bats live in open, arid habitats in Australia, and in savanna woodlands or the more arid areas of Africa and India.

Behavior

False vampire bats roost in a variety of situations, from caves and mines, to tree hollows and buildings. The African yellow-winged bat (Lavia frons) roosts by hanging from tree branches. Unlike some other species of bat, false vampire bats are warm-blooded and cannot enter torpor, a state of total inactivity.

Feeding ecology and diet

Broad-winged bats with low-wing loading, false vampire bats are capable of flying and maneuvering in areas of vegetation. They may take prey from surfaces (the ground or vegetation) or in flight. False vampire bats eat animals ranging from arthropods to vertebrates, including bats, birds, fish, frogs, and lizards, with larger species taking larger prey. False vampire bats use at least three approaches to finding prey. Often they identify prey-generated sounds such as the footfalls of large arthropods or mice. They may also use vision and, at least in experimental situations, greater false vampire bats used echolocation to find frogs. Prior to foraging in the evening, false vampire bats as well as heart-nosed bats (Cardioderma

cor) sing from perches in their hunting areas. Their songs appear to be territorial advertisements.

Reproductive biology

Female false vampire bats produce a single young each year. The gestation period is about 90 days and young are born at the beginning of the rainy season. Mating system varies by species.

Conservation status

The IUCN lists the heart-nosed bat as being Lower Risk/Near Threatened. The Australian false vampire bat (Macroderma gigas) is listed as Vulnerable.

Significance to humans

None known.

Species accounts

List of Species

Yellow-winged bat

Lavia frons

taxonomy

Megaderma frons (Geoffroy, 1810), Senegal.

other common names

French: Chauve-souris orangée.

physical characteristics

These are medium-sized bats, with forearm lengths ranging from 2.0–2.5 in (5.3–6.4 cm), and weighing 0.88–1.23 oz (25–35g). The combination of yellowish wings and ears and a long, blunt nose-leaf distinguish yellow-winged bats from the only other African megadermatid, Cardioderma cor. The bat's large ears, bifurcate tragi, and broad wings are typical for the family.

distribution

Widespread in sub-Saharan Africa, occurring from Gambia and Senegal through west Africa to Sudan, Ethiopia, and south to Malawi and Zambia. Also through Nigeria, Cameroon, Central African Republic, Congo, Gabon, and northern Angola.

habitat

Inhabit savanna woodland.

behavior

Roost by day 16.4–32.8 ft (5–10 m) above the ground, hanging from small branches in acacia trees. Roosting bats are alert and difficult to approach. Typically, one pair (adult male and adult female) occupies a territory and both members of the pair often move between roosts, apparently to follow shade. They use social calls that are audible to people, and also higher frequency calls in echolocation.

feeding ecology and diet

Insectivorous, they hunt well above the ground, taking flying insects as well as walking insects and other arthropods from surfaces such as foliage, the trunks, and limbs of trees. Other prey include termites, beetles, moths, katydids, and flies.

reproductive biology

Appear to be monogamous, with pairs (one adult male, one adult female) remaining together at least through one reproductive season. At the end of the dry season after three-months gestation, females bear a single young annually. At first, foraging females carry their young, but later leave them alone when hunting. As they approach adult size, young bats hang by their hind feet from their mothers' shoulders and flap their wings, in preparation for their own flights.

conservation status

Not threatened.

significance to humans

None known.

Australian false vampire bat

Macroderma gigas

taxonomy

Megaderma gigas Dobson, 1880, Queensland, Australia.

other common names

English: Ghost bat.

physical characteristics

One of the largest bats, they have forearms 3.7–4.6 in (9.6–11.8 cm) long, and weigh 2.6–5.0 oz (74–144 g). They have huge ears, large eyes, and prominent nose-leaves, with fur that varies from light brown to almost white (hence the name "ghost bat."

distribution

Today their populations occur in north Queensland, along the north central coast, and in the northwest.

habitat

Occur in habitats from arid hillsides, grasslands, and monsoon forest, to savanna woodland and other forests.

behavior

Roost in hollows, usually in caves or abandoned mines, sometimes forming colonies of more than 1,000 individuals. Very vocal in their roosts, producing both lower frequency signals audible to humans, and higher frequency echolocation calls.

feeding ecology and diet

Consume animals ranging in size from insects such as cockroaches to vertebrates from frogs and geckoes to birds and other species of bats. When hunting, these bats sometimes hang in wait from a branch and attack passing prey, taking it either from the ground or in flight. Their hunting perches can be recognized by distinctive claw marks left on small tree branches.

reproductive biology

Mating occurs in May and each female bears a single young in July. Mothers stay with their young for some time, including flying together to forage after the young is large enough. May be promiscuous.

conservation status

Vulnerable.

significance to humans

Australian false vampire bats have great spiritual significance to Australian aborigines.

Resources

Books

Churchill, S. Australian Bats. Sydney: Reed New Holland, 1998.

Hutson, A. M., S. P. Mickelburgh, and P. A. Racey. Global Status Survey and Conservation Action Plan, Microchiropteran Bats. Gland, Switzerland: IUCN SSC Chiroptera Specialist Group, 2001.

Kingdon, J. Mammals of East Africa: An Atlas of Evolution, Volume 2b. New York: Academic Press, 1974.

Nowak, R. M. Walker's Mammals of the World, Vol. 1. Baltimore: Johns Hopkins University Press, 1999.

Periodicals

Csada, R. "Cardioderma cor." Mammalian Species 519 (1998): 1–4.

Hudson, W. S., and D. E. Wilson. "Macroderma gigas." Mammalian Species 260 (1986): 1–4.

Vonhof, M. J., and M. C. Kalcounis. "Lavia frons." Mammalian Species 614 (1999): 1–4.

Melville Brockett Fenton, PhD