Balionycteris maculataspotted-winged fruit bat

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Geographic Range

Spotted-winged fruit bats are native to Thailand, Malaysia, and Borneo. (Corbert and Hill, 1980)

Habitat

Spotted-winged fruit bats prefer forests, lowlands, or foothills, and are commonly found in and around Eastern Asia. (Anderson and Jones , 1984)

Physical Description

Balionycteris maculata can grow to be about 50 to 66 mm in length, and can weigh up to 14.5 g. They have no external tail, a short nose, and the length of their forearm ranges from 39 to 43 mm. (Nowak, 1999)

These fruit bats have unique dentition, in that they only have one pair of lower incisors.

The color of pelage can range from sooty brown to a grayish tint. Balionycteris maculata has a black head and the wings are marked with yellow spots. A baculum is present in males. (Nowak, 1999)

The only other bat with which this species could be confused is Chironax melanocephalus, or black-capped fruit bats. These two species which share similar external characteristics, although the latter is slightly smaller, differs in dental characters, and lacks spots on the wings. (Nowak, 1999)

  • Range mass
    9.5 to 14.5 g
    0.33 to 0.51 oz
  • Range length
    50 to 66 mm
    1.97 to 2.60 in
  • Range wingspan
    39 to 44 mm
    1.54 to 1.73 in

Reproduction

No information was found on mating systems.

Data on the reproductive characteristics of this species are lacking. However, it is likely that B. maculata 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 1 to 2 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. (Anderson and Jones , 1984; Anderson and Jones , 1984)

  • Breeding interval
    The breeding interval of this species is not known, but is likely to be once or twice per year.
  • Breeding season
    The breeding season of these animals has not been reported, but is likely to be throughout the year.
  • Range number of offspring
    1 to 2
  • Average number of offspring
    1
  • Average age at sexual or reproductive maturity (female)
    2 years
  • Average age at sexual or reproductive maturity (male)
    2 years

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. (Nowak, 1999)

  • Parental Investment
  • no parental involvement
  • pre-fertilization
    • protecting
      • female
  • pre-hatching/birth
    • provisioning
      • female
    • protecting
      • female
  • pre-weaning/fledging
    • provisioning
      • female
    • protecting
      • female
  • pre-independence
    • protecting

Lifespan/Longevity

No information on the lifespan/longevity of this species is available. As the only member of the genus Balionycteris, it is not even possible to generalize from closely related species. (Nowak, 1999)

Behavior

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 10. (Anderson and Jones , 1984)

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. Along with both of their powerful bite, their canines are well developed. The bats locate food by smellas well as by sight. Most do not have a well-developed echolocation. (Anderson and Jones , 1984)

Some bats migrate seasonally to find fruit, although there are no details on such behavior available for B. maculata. These bats are relatively slow flyers, and hibernation has been reported. (Anderson and Jones , 1984; Harrison, 1974; Nowak, 1999)

Home Range

The size of the home range of this species has not been reported.

Communication and Perception

Balionycteris maculata uses a variety of postures in communciation, as well as a number of noises. These bats are reported to be very vocal. It is likely that tactile communication is important in the roost, between mates, rival, and between parents and their offspring. The role of scent cues in communication in this species has not been documented, but is probably at least minimally important. (Anderson and Jones , 1984)

Food Habits

As the common name suggests, this mammal is frugivorous, primarily feeding on fruit, pollen, and nectar. Balionycteris maculata consumes fruit by utilizing the juices and spitting out the fibers. It has been reported that this animal also feeds on insects. (Anderson and Jones , 1984)

  • Animal Foods
  • insects
  • Plant Foods
  • fruit
  • nectar
  • flowers

Predation

Predators of this species have not been reported.

Ecosystem Roles

These bats are frugivores and may be important in seed dispersal. (Nowak, 1999)

  • Ecosystem Impact
  • disperses seeds

Economic Importance for Humans: Positive

There is no information avaiable suggesting any positive economic impact of these animals on humans.

Economic Importance for Humans: Negative

Occasionally B. maculata has been know to damage fruit crops, reducing the fruit yield for local farmers. (Anderson and Jones , 1984)

  • Negative Impacts
  • crop pest

Conservation Status

From what I have gathered there has not been a special status that has been placed on this mammal.

Contributors

Nancy Shefferly (editor), Animal Diversity Web.

Ryan Rubbelke (author), University of Wisconsin-Stevens Point, Chris Yahnke (editor, instructor), University of Wisconsin-Stevens Point.

Glossary

acoustic

uses sound to communicate

arboreal

Referring to an animal that lives in trees; tree-climbing.

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

chemical

uses smells or other chemicals to communicate

crepuscular

active at dawn and dusk

delayed implantation

in mammals, a condition in which a fertilized egg reaches the uterus but delays its implantation in the uterine lining, sometimes for several months.

diurnal
  1. active during the day, 2. lasting for one day.
echolocation

The process by which an animal locates itself with respect to other animals and objects by emitting sound waves and sensing the pattern of the reflected sound waves.

endothermic

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

fertilization

union of egg and spermatozoan

forest

forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.

frugivore

an animal that mainly eats fruit

herbivore

An animal that eats mainly plants or parts of plants.

island endemic

animals that live only on an island or set of islands.

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

migratory

makes seasonal movements between breeding and wintering grounds

motile

having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.

nocturnal

active during the night

oceanic islands

islands that are not part of continental shelf areas, they are not, and have never been, connected to a continental land mass, most typically these are volcanic islands.

oriental

found in the oriental region of the world. In other words, India and southeast Asia.

World Map

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

social

associates with others of its species; forms social groups.

tactile

uses touch to communicate

temperate

that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).

terrestrial

Living on the ground.

tropical

the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.

ultrasound

uses sound above the range of human hearing for either navigation or communication or both

visual

uses sight to communicate

viviparous

reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.

year-round breeding

breeding takes place throughout the year

References

Anderson, S., J. Jones . 1984. Orders and Families of Recent Mammals of the World. New York: The American Society of Mammalogists.

Corbert, G., J. Hill. 1980. A World List of Mammalian Species. Britain: British Museum.

Harrison, J. 1974. An Introduction to Mammals of Singapore and Malaya. Singapore: Singapore Branch Malayan Nature Society.

Nowak, R. 1999. Walker's Mammals of the World, Sixth Edition. Baltimore and London: The Johns Hopkins University Press.