Nyctimene albiventercommon tube-nosed fruit bat

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Geographic Range

Nyctimene albiventer occurs in the Halmahera Islands, Banda and Aru Islands, Bismarck Archipelago, Moluccas, New Guinea, Admiralty and Solomon Islands and the Cape York peninsula of Australia (Nowak, 1999; Boitani, 1982).

Habitat

Known to inhabit primary and secondary rainforest, primary montane forest, sago swamp, and areas surrounding native gardens (Nowak, 1999).

Physical Description

N. albiventer is a medium-sized, yet robust fruit bat with a large, rounded head. These bats have large eyes, long, tubular nostrils that extend sideways from the face, and a short tail. The fur is soft and long, grayish brown above, but darker along mid-back and on the spinal stripe. The underparts are usually yellowish-white. The neck and sides are tinged with yellow-orange. The ears and wings are splattered with irregular yellow spots. This mottled fur may help them to remain concealed while hanging in their resting position (Nowak, 1999). The length of head and body about 8-9 cm. The forearm is 5.5-6 cm (2.2-2.4 in) long. These bats weigh up to 45 g (1.6 oz). (Boitani, 1982)

  • Range mass
    45 (high) g
    1.59 (high) oz
  • Range length
    8 to 9 cm
    3.15 to 3.54 in

Reproduction

The mating system of these bats is unknown.

Reproductive behavior is not well documented for this species. N. albiventer may have two annual breeding seasons, in early winter and in late summer, or they breed year-round. Pregnant females with one embryo each have been taken in January, July, and August. Lactating females have been taken in February, May and August (Nowak, 1999). All records on reproduction emminate from Papua New Guinea, so breeding season may vary in ther locations.

Records for congeneric N. rabori indicate that preganancy lasts 4.5 to 5 months, and lactation continues for 3 or 4 months. Females can first become pregnant at 7 to 8 months of age (Nowak, 1999).

  • Breeding season
    Breeding may occur year round, and pregnant females have been taken in January, July, and August.
  • Average number of offspring
    1

Females nurse the young. Male parental care has not been reported, but little is known about reproduction in these animals.

Lifespan/Longevity

The lifespan of these bats has not been documented.

Behavior

By day these bats roost singly on tree trunks or hanging from branches, well concealed by their protective coloration. The spots on the wings and ears look like splattered enamel paint and are sometimes chartreuse, a color common to tropical vegetation. At night tube-nosed bats feed on soft fruits and nectar, while either hovering in front of the blossoms or climbing among flower clusters (Boitani, 1982).

Communication and Perception

Although not much is know about how N. albiventer communicates, it is known to emmit high whistling calls in mid flight. Their peculiar nostrils may be an adaptation to their feeding habits or may function in sound production. The nasal tubes stretch and vibrate when the bat utters its high whistling call in flight (Boitani, 1982).

Food Habits

N. albiventer is known to mainly be a frugivore. However, Vestjens and Hall (1977) reported that the stomachs of three N. albiventer individuals contained insects. Most other stomachs contained fruit or vegetable matter. Earlier observations indicated that captive individuals prefer soft, juicy fruits and would not take insects that were offered.

In order to eat, the animal hangs horizontally or obliquely in a fruit bush with its thumbs inserted into the fruit. It turns its lips up on the fruit and bites off pieces with its lower jaw. The upper teeth aid the lips in supporting the lower jaw. The bat shoves the bitten pieces toward its breast and the belly with its muzzle, then vhews them up to extract the juice. A fringe of fleshy lobes on the inner edge of the lips seems to assist the bat in this processing. Captives that fed on guavas were not observed to bite into the inside of the fruit, and the nostrils did not come in contact with the fruit at any time. The pulp of young coconuts is also eaten (Nowak, 1999).

Foods eaten include: soft fruit, nectar and some insects.

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

Predation

Predation upon these bats has not been reported. However, it is thought that the mottled pattern on the fur may help them to remain concealed while they are in their resting position (Nowak, 1999).

Ecosystem Roles

Since N. albiventer is a frugivore, it may play an essential role in seed dispersal for many of the local plant species.

  • Ecosystem Impact
  • disperses seeds

Economic Importance for Humans: Positive

There are no known positive interactions between these bats and humans.

Economic Importance for Humans: Negative

These bats are not known to have a negative impact on human economies.

Conservation Status

These bats have no special conservation status. However, several members of the genus are near threatened, vulnerable, or critically endangered according to the IUCN. Habitat destruction seems to be the principle threat to the genus, and it is likely that deforestation could eventually affect N. albiventer as well as its close relatives.

Other Comments

There appears to be considerable active debate regarding the taxonomy of this genus of bats. Authorities sometimes split populations on different islands into different species or subspecies. Other authorities lump various island populations together as a single species. It is likely that these problems of taxonomy affect whether species are viewed as threatened or endangered (Nowak, 1999).

Contributors

Marlon Gil (author), Humboldt State University, Brian Arbogast (editor), Humboldt State University.

Glossary

Australian

Living in Australia, New Zealand, Tasmania, New Guinea and associated islands.

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acoustic

uses sound to communicate

agricultural

living in landscapes dominated by human agriculture.

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

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.

female parental care

parental care is carried out by females

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.

internal fertilization

fertilization takes place within the female's body

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).

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

oriental

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

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rainforest

rainforests, both temperate and tropical, are dominated by trees often forming a closed canopy with little light reaching the ground. Epiphytes and climbing plants are also abundant. Precipitation is typically not limiting, but may be somewhat seasonal.

sexual

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

solitary

lives alone

swamp

a wetland area that may be permanently or intermittently covered in water, often dominated by woody vegetation.

tactile

uses touch to communicate

tropical

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

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.

References

Boitani, L., S. Bartoli. 1982. Simon and Schuster's Guide to Mammals. New York: Simon and Schuster Inc..

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

Vestjens, W., L. Hall. 1977. Stomach contents of forty-two species of bats from the Australian region. Austral. Wildl. Res., 4: 25-35.