Western Bent-winged Bat (Miniopterus magnater)


Bent-winged or Long-fingered Bats are so called because of the relatively long terminal bone of the middle finger, compared to the middle bone. As a result, the end part of the wing is folded back and tucked underneath the rest of the wing when roosting.

The true number of species of Miniopterus bats is unclear, but at least 11 are generally agreed to exist. There are great similarities between all species, which are often distinguished only on the basis of forearm length and weight. Identification of species on the basis of photographs alone is not possible.

In all species the fur is thick and generally brown-black to brown, or sometimes reddish. The ears are relatively small and rounded, and the eyes small.

Many bent-winged bat species roost in large colonies in caves : these bats may become spectacularly abundant in tropical rainforests where karst limestone habitats provide cave systems for roosting. For example in parts of Borneo there are colonies of over 100,000 bats. These colonies are well organised : it is known that thousands of juveniles may be left together by night under the care of a few females while their parents are out foraging for food. They feed on flying insects, particularly moths, high in the forest canopy.

Some species are wide-ranging across Southeast Asia, New Guinea and beyond. The Common Bent-winged Bat Miniopterus schreibersi has a range that extends from parts of Africa, across southern Europe and Asia to Australia and Oceania. The range of elevations is also large : in New Guinea some species occur up to 3200 metres above sea level.

 Range Description:

This species appears to be widely distributed from Myanmar in the west (recorded from Hpoan and Mawlamyine; Bates et al. 2000), through Southern China (including Hainan Island) and much of Southeast Asia, as far east as the island of New Guinea. Within this range it has been recorded from many island localities including Sumatra (a single locality; Indonesia), Western Java (Indonesia), Northern Borneo (Sabah, Malaysia and Kalimantan, Indonesia), Timor (East Timor and Indonesia), and Seram (Indonesia). Thailand and Vietnam A number of records of Miniopterus schreibersii have been re-identified as Miniopterus magnater (T. Reardon pers. comm.). It has been recorded from sea level to 2,100 m asl, but this is not clear given identification problems.
Countries: Native:
Indonesia; Papua New Guinea


The population abundance of this species is not known.
Population Trend: Unknown

 Habitat and Ecology:

This is a cave roosting species, often found roosting with other bat species. It possibly forms large colonies. It has been recorded foraging generally above the canopy in primary and secondary tropical forest, and also close to human settlements. Bonaccorso (1998) and Payne et al. (1985) noted that they may be seen hawking insects around street lights, but this is not certain given identification problems.
Systems: Terrestrial

 Major Threat(s):

There are no known major threats to this species. It is presumed to be threatened by cave disturbance and degradation in some parts of its range.

 Conservation Actions:

This species is present in a number of protected areas. Hendrichsen et al. (2001) recorded it in Vietnam at Pu Mat National Park, Cuc Phuong National Park, and at Toong Ching. The urgent priority with this species is to resolve Miniopterus taxonomy and identification in order to understand the distribution, abundance, habitat requirements, ecology, and threats to it. There is a need to protect important roosting and foraging sites of this species.