Bats

Dobsonia magna

Bare-backed fruit bat

Distribution

This species is found in northern Queensland from Cooktown to Cape York. Extralimital distribution includes New Guinea and the islands adjacent to the north and west coasts of New Guinea.

A bare backed batDescription

This fruit bat is immediately distinguished from flying foxes by its apparently hairless back. The wing membrane joins along the midline of the back rather than along the sides of the body, giving the appearance of a furless back. Under the wing membrane, the back is fully furred. The fur on the head and shoulders is black-brown while the belly fur is lighter grey-brown and sparsely furred. Photo: H. Millen in L. S. Hall (1983).

Habitat

The Bare-backed fruit bat roosts in rainforest and tropical woodlands. In Australia, they form colonies of fewer than100, while in New Guinea they are found in colonies of many thousands. They roost in twilight conditions in caves, under large piles of boulders, in disused mines, abandoned houses, concrete bunkers and dense vegetation. This species is the only Australian megachiropteran to roost in caves.

A bare backed batDiet and Foraging

They feed on a variety of native fruits including figs, and blossom such as bloodwood. They also eat cultivated fruits including banana and paw-paw. Like flying foxes, they tend to follow watercourses when commuting between roost and feeding sites, but forage alone. Photo: H. Millen in L. S. Hall (1983).

Reproduction

Reproductive activity begins between April and June when the female develops folds of flesh around the vagina and the male develops a scent gland on the neck and shoulder. Copulation takes place in May and June, and following a five-month gestation, single young are born between September and November. The mother carries the pup for about one month and will nurse it for a further 4 to 5 months. Weaning occurs at the peak of the wet season in January to February.

Measurements

Weight: Mean 374 g (Min. 360 g, Max 600 g)

Forearm length: Mean 149 mm (Min. 140 mm, Max 157 mm)

Source: S. Churchill.

Author: C. de Jong.

References

Churchill, S. (1998) Australian Bats, Reed New Holland, Sydney, pp. 72-73.

Hall, L. S. (1983) Bare-backed fruit bat. In R. Strahan (ed.). The Mammals of Australia, Reed Books, Chatswood, pp. 284-285.