The spotted-winged fruit bat, (''Balionycteris maculata'') is the smallest

megabat Megabats constitute the family Pteropodidae of the order Chiroptera ( bats). They are also called fruit bats, Old World fruit bats, or—especially the genera '' Acerodon'' and '' Pteropus''— flying foxes. They are the only member of the ...

in the world, and the only species in the genus ''Balionycteris''. It inhabits forests in

Indonesia Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania between the Indian and Pacific oceans. It consists of over 17,000 islands, including Sumatra, Java, Sulawesi, and parts of Borneo and New Guine ...

and

Malaysia Malaysia ( ; ) is a country in Southeast Asia. The federation, federal constitutional monarchy consists of States and federal territories of Malaysia, thirteen states and three federal territories, separated by the South China Sea into two r ...

Description

Spotted-winged fruit bats are unusually small megabats, with a head-body length of , a wingspan of , and an adult body weight of around . Most of the head and body are covered in thick blackish-brown fur, while the underparts are a pale grey-brown. Their wings are dark brown, with distinctive pale cream spots, which are most noticeable on the joints, but are also found in a variable pattern across the wing membranes. The wings have been reported to have an aspect ratio of 5.8 and a

wing loading In aerodynamics, wing loading is the total mass of an aircraft or flying animal divided by the area of its wing. The stalling speed of an aircraft in straight, level flight is partly determined by its wing loading. An aircraft or animal with a ...

of 9.51 N/m². There are also pale markings in front of the large eyes, and on the ears, which are simple in shape, compared with those of

microbat Microbats constitute the suborder Microchiroptera within the order Chiroptera ( bats). Bats have long been differentiated into Megachiroptera (megabats) and Microchiroptera, based on their size, the use of echolocation by the Microchiroptera a ...

s. The nostrils are elongated, and splayed to the side of the snout. The species can be distinguished from other small fruit bats by the presence of the spots on its wings, but also by its unusual dental formula of .

Distribution and habitat

Spotted-winged fruit bats inhabit

primary Primary or primaries may refer to: Arts, entertainment, and media Music Groups and labels * Primary (band), from Australia * Primary (musician), hip hop musician and record producer from South Korea * Primary Music, Israeli record label Work ...

rain forest Rainforests are characterized by a closed and continuous tree canopy, moisture-dependent vegetation, the presence of epiphytes and lianas and the absence of wildfire. Rainforest can be classified as tropical rainforest or temperate rainforest ...

up to elevation, and coastal

mangrove A mangrove is a shrub or tree that grows in coastal saline or brackish water. The term is also used for tropical coastal vegetation consisting of such species. Mangroves are taxonomically diverse, as a result of convergent evolution in several ...

forests. They are found across

and

Brunei Brunei ( , ), formally Brunei Darussalam ( ms, Negara Brunei Darussalam, Jawi alphabet, Jawi: , ), is a country located on the north coast of the island of Borneo in Southeast Asia. Apart from its South China Sea coast, it is completely sur ...

, and in the northern and western parts of the island of

Borneo Borneo (; id, Kalimantan) is the List of islands by area, third-largest island in the world and the largest in Asia. At the geographic centre of Maritime Southeast Asia, in relation to major Indonesian islands, it is located north of Java Isl ...

. At the edges of their range, they have also been reported from Trang Province in southern

Thailand Thailand ( ), historically known as Siam () and officially the Kingdom of Thailand, is a country in Southeast Asia, located at the centre of the Indochinese Peninsula, spanning , with a population of almost 70 million. The country is b ...

, from a small area in Sumatra, and from the

Riau Archipelago The Riau Archipelago is a ''geographic'' term (as opposed to administrative region) for the core group of islands within the Riau Islands Province in Indonesia, and located south of Singapore and east of Riau on Sumatra. Before the province of Ri ...

. No subspecies are known.

Behaviour and biology

Spotted-winged fruit bats forage in the understory of dense forest where they feed on a range of generally small, inconspicuous fruit, such as

fig The fig is the edible fruit of ''Ficus carica'', a species of small tree in the flowering plant family Moraceae. Native to the Mediterranean and western Asia, it has been cultivated since ancient times and is now widely grown throughout the world ...

s and

persimmon The persimmon is the edible fruit of a number of species of trees in the genus ''Diospyros''. The most widely cultivated of these is the Oriental persimmon, '' Diospyros kaki'' ''Diospyros'' is in the family Ebenaceae, and a number of non-pe ...

, and on some insects and spiders. They spend the day roosting alone or in small groups consisting of a male and up to nine females and their young. Rather than remaining with a single male, females may visit up to three different males. Males return regularly to their roosts during the night, suggesting that they gain access to females by controlling and defending prime roosting sites. They forage as individuals, rather than in a group, and rarely travel more than from their roost site. They have been observed to make high-pitched "peep" noises when foraging, as well as more complex series of sounds when socialising. Roosts are of a consistent shape and size, and may be partially excavated by the bats, a behaviour that is otherwise unknown in this group of animals. They are generally located in the root masses of

epiphytic An epiphyte is an organism that grows on the surface of a plant and derives its moisture and nutrients from the air, rain, water (in marine environments) or from debris accumulating around it. The plants on which epiphytes grow are called phoroph ...

plants, such as ferns, and also in the nests of ants and termites. Females give birth to a single young up to twice a year, typically between June and January. The young are born blind, and weighing around , after a gestation of 135 days. They are weaned by 40–80 days, and are able to fly by the time they have reached in weight. Females are sexually mature at ten months of age.

References

External links

*ARKive
images and movies of the spotted-winged fruit bat ''(Balionycteris maculata)''
{{Taxonbar, from=Q134342 Megabats Bats of Southeast Asia Bats of Indonesia Bats of Malaysia Mammals of Borneo Mammals of Brunei Mammals of Thailand Mammals described in 1893 Taxa named by Oldfield Thomas