Spotted Fruit Bat

Balionycteris maculata

spotted-winged fruit bat

Information Classification

2008/05/11 10:47:45.630 GMT-4

By Ryan Rubbelke

Kingdom: Animalia

Phylum: Chordata

Subphylum: Vertebrata

Class: Mammalia

Order: Chiroptera

Family: Pteropodidae

Genus: Balionycteris

Species: Balionycteris maculataGeographic Range

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

Biogeographic Regions:

oriental (native ); oceanic islands (native ).

Other Geographic Terms:

island endemic .

Habitat

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

These animals are found in the following types of habitat:

temperate ; tropical ; terrestrial .

Terrestrial Biomes:

forest .

Physical Description

Mass

9.50 to 14.50 g

(0.33 to 0.51 oz)

Length

50 to 66 mm

(1.97 to 2.6 in)

Wingspan

39 to 44 mm

(1.54 to 1.73 in)

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)

Some key physical features:

endothermic ; homoiothermic; bilateral symmetry .

Reproduction

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.

Number of offspring

1 to 2; avg. 1

Age at sexual or reproductive maturity (female)

2 years (average)

Age at sexual or reproductive maturity (male)

2 years (average)

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)

Key reproductive features:

iteroparous ; year-round breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization ; viviparous ; delayed implantation .

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