The Spotted-wing fruit bat (scientific name: Balionycteris maculata) is the smallest fruit bat in the world. Like all fruit bats in the Old World tropics, the Spotted-wing fruit bat has very large eyes, because it relys on vision to navigate at night. Unlike the insectivorous bats, the Old World fruit bats do not echolocate with ultrasonic frequencies, although several species do click their tongues as a very simple form of echolocation when in their caves.
Source: Malaysian Bat Education Adventure
IUCN Conservation Status - Least Concern.
Scientific ClassificationKingdom: Animalia
Balionycteris maculata (Thomas, 1893)
The Spotted-wing fruit bat is the smallest species in the order Chiropteraca: it can achieve a length of 50 to 66 millimeters (mm), and can have a body mass as high as 14.5 grams. This creature, as the smallest member of the flying foxes, has no external tail, but manifests a short nose, and a length of the forearm ranging from 39 to 43 mm. This fruit-eating bat has a claw on the second digit of each hand, enabling it to cling to fruit trees and break into tough-skinned fruit with its strong jaws.
The wings are broad and rounded and are a dark brown flecked with small whitish or pink spots, particularly on the finger joints. This is how Balionycteris maculata derives its name, since maculata comes from the latin word for spotted, maculatus.
The black, dog-like face has large eyes, with a pale spot beneath each. The nostrils are long and somewhat tubular, and the ears are small. These fruit bats have unique dentition, in that they only have one pair of lower incisors.
The soft fur is very dark brown on the back, and paler on the underside. Pale spots contrast with the dark wing membranes, and often highlight the joints of the finger bones.
This species is found in southern Thailand, western Peninsular Malaysia, Borneo, Sumatra, and the Durian and Galang Islands.
Balionycteris maculata occurs chiefly in forest habitats, the Spotted-winged fruit bat roosts primarily in the lower canopy. It is found from the lowlands to montane forest, and prefers to roost in palm trees and ferns that grow on the trunks of large forest trees, as well as in the active nests of tree-dwelling ants, and the unoccupied tree-nests of termites. The small size and excellent manouvreability of this species enables it to forage in the cluttered forest understory, where larger fruit bats have difficulties flying.
Food and Feeding Behavior
As the common name suggests, this mammal is frugivorous, primarily feeding on fruit, pollen, and nectar, and they are particularly fond of small figs. Both male and females forage within approximately on kilometer of their roost. They consumes fruit by utilizing the juices and spitting out the fibers. It has been reported that this animal also feeds on insects. The bats locate food by smell as well as by sight. This species does not exhibit an advanced echolocation system.
Although mostly nocturnal, some of these bats have been seen during the day. They are generally tree-dwelling, although have been seen in the limestone caverns in Sabah. They generally roost in groups of more than ten.
Spotted-winged fruit bats are homoeothermic, and rectal tests have shown temperatures ranging from 31 to 37 degrees Celsius. These bats have shortened jaws and a powerful bite for eating fruit.
It roosts in small groups in bell-shaped cavities that are hollowed out from vegetation matter in the crowns of palms, and in ferns on forest trees. It has also been found in live nests of ants in trees and in abandoned termite nests. It is thought that the males actually excavate these roost cavities– once he has made a nice safe hollow, he can attract females, so typically Balionycteris maculuta is found in harem groups of up to fourteen bats, with one male and several females and their dependent young.
There is no information was found on mating systems or reproductive characteristics of this species. However, it is likely that the Spotted-wing fruit bat is similar to other temperate/tropical fruit bats. Most fruit bats reach puberty in the second year after birth. Copulation is accomplished while suspended by the hind legs in the roost. Females can produce one to two young per year, although typically only give birth to one young at a time. Fruit bats are known to breed throughout the year, with young being born every month of the year. Delayed implantation may occur.
Parental care in this species has not been documented. However, as mammals, females of this species are known to provide their young with milk and protection. The mother probably also grooms her offspring, and cares for them while they reach maturity. The role of males in parental care has not been established.
This sensitive species relies on a deep and productive forest and constant deforestation throughout its range threatens its population stability. The rapid increase in land devoted to growing oil palm has resulted in extensive loss of primary forest. Together, Malaysia and Indonesia export 88% of the world's palm oil, for use in products such as margarine, lipstick and detergent. Deforestation continues at a steady rate for conversion to agricultural land and building communities, and despite the contribution of many bats to the pollination and seed dispersal of many fruit crops, persecution of bats is also a threat
The Spotted-winged fruit bat has been classified as Least Concern (LC) on the IUCN Red List
References and Further Reading
- Encylopedia of Life. 2011. Balionycteris maculata (Thomas, 1893) EOL accessed October 6, 2011
- Hall LS, Gordon G. Grigg, Craig Moritz, Besar Ketol, Isa Sait, Wahab Marni and M.T. Abdullah. 2004. Biogeography of fruit bats in Southeast Asia. Sarawak Museum Journal LX(81):191-284.
- Karim, C., A.A. Tuen and M.T. Abdullah. 2004. Mammals. Sarawak Museum Journal Special. Issue No. 6. 80: 221—234.
- Mohd. Azlan J., Ibnu Maryanto , Agus P. Kartono and M.T. Abdullah. 2003 Diversity, Relative Abundance and Conservation of Chiropterans in Kayan Mentarang National Park, East Kalimantan, Indonesia. Sarawak Museum Journal 79: 251-265.
- Hall LS, Richards GC, Abdullah MT. 2002. The bats of Niah National Park, Sarawak. Sarawak Museum Journal. 78: 255-282.
- Balionycteris maculata Malaysian Bat Education Adventure (includes a video)