Cynopterus brachyotislesser short-nosed fruit bat

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Geographic Range

Cynopterus brachyotis is distributed in Sri Lanka, the Andaman and Nicobar Islands, southern Burma, Thailand, southern China, Indochina, Malay Peninsula, Sumatra, Java, Kangean Islands, Borneo, Bali, Sulawesi, and the Philippines. (Nowak, 1997)

Habitat

Cynopterus brachyotis is phytophilic (plant-loving). It can be found in tropical rainforests sleeping under modified palm leaves, as well as orchid leaves. (Crichton and Krutzsch, 2000; Richarz and Limbrunner, 1993)

Physical Description

Cynopterus brachyotis has a fox-like face, large dark eyes, short brown hair, and dark, spotted wings.

The length of the head and body in this genus is 70 to 127 mm. The tail adds an additional 6 to 15 mm to the overall length. The forearms of these bats are from 55 to 92 mm long, giving them a wingspan ranging from 305 to 457 mm. Adults weigh about 30 to 100 grams. (Nowak, 1997; Schultes, 2003)

Cynopterus brachyotis is distinguishable from C. sphynx in that the ears of C. brachyotis are, on average, smaller than those of C. sphynx. (Andersen, 1912)

  • Range mass
    30 to 100 g
    1.06 to 3.52 oz
  • Range length
    70 to 127 mm
    2.76 to 5.00 in
  • Range wingspan
    305 to 457 mm
    12.01 to 17.99 in
  • Average basal metabolic rate
    0.262 W
    AnAge

Development

Gestation time unknown.

Reproduction

The mating system of these animals has not been described. However, based on the association of one male with multiple females, it is most likely polygynous.

In the Malay Peninsula, breeding is apparently aseasonal, and C. brachyotis may be found pregnant throughout the year. In Thailand breeding is also aseasonal; pregnancies peak from March to June, as well as in January and September. Gestation is thought to last about 120 days, after which the female gives birth to a single young. (Nowak, 1997)

Although data are not available for this species, C. sphinx is reported to weigh 11 grams at birth. Neonates are carried by the mother, and are weaned at 40 to 45 days of age. Female C. sphinx reach sexual maturity at 5 to 6 months of age, with males maturing much later, at 15 to 20 months of age. It is likely that C. brachyotis is similar in these parameters. (Nowak, 1997)

Reproduction in C. brachyotis is timed so that lactation corresponds with the peak of the rainy season--which is the fruiting season. (Crichton and Krutzsch, 2000)

  • Breeding interval
    It is not known how often these animals breed.
  • Breeding season
    These bats breed aseasonally.
  • Range number of offspring
    1 (low)
  • Average number of offspring
    1
  • Average number of offspring
    1
    AnAge
  • Average gestation period
    120 days
  • Average weaning age
    45 days
  • Range age at sexual or reproductive maturity (female)
    5 to 6 months
  • Range age at sexual or reproductive maturity (male)
    15 to 20 months

Young can cling to the mother from birth, but must be carried for over a month. Both the male and female care for the young. Males have mammary glands that are equal in size to the females’ (greater than 8% of total body mass), so males are thought to play an active role in lactation and feeding young. (Crichton and Krutzsch, 2000)

  • Parental Investment
  • altricial
  • pre-fertilization
    • provisioning
    • protecting
      • female
  • pre-hatching/birth
    • provisioning
      • female
    • protecting
      • female
  • pre-weaning/fledging
    • provisioning
      • male
      • female
    • protecting
      • male
      • female

Lifespan/Longevity

Cynopterus brachyotis lives about 20 to 30 years. (Crichton and Krutzsch, 2000)

  • Range lifespan
    Status: wild
    20 to 30 years
  • Average lifespan
    Status: captivity
    10.1 years
    AnAge

Behavior

Individual C. brachyotis roost alone (young males) or in groups (usually one male and about four females, although there are sometimes up to twenty females in these groups). (Richarz and Limbrunner, 1993)

These bats are known to construct shelters. They sometimes bite off the center part of palm fruit clusters, thereby leaving a hollow in which to hang. Males spend up to two months chewing the veins of leaves and palm fronds until they fall and are ready to be formed into a shelter. (Nowak, 1997; Nowak, 1997)

Home Range

The home range size for these animals has not been reported.

Communication and Perception

Cynopterus brachyotis communicates using tactile, visual, and acoustic stimuli. They use their acute sense of smell to find food and rely on their keen vision to navigate. (Crichton and Krutzsch, 2000)

Food Habits

Cynopterus brachyotis is frugivorous. These bats feed on fruit, mostly mangoes, but also any fruit that is aromatic and available. They are thought to consume mainly the juices of the fruits and to expel the pulp. (Crichton and Krutzsch, 2000; Nowak, 1997)

  • Plant Foods
  • fruit

Predation

Ability to fly has kept C. brachyotis relatively free from terrestrial carnivores. However, in some cultures, humans consider them a delicacy. (Nowak, 1997)

Ecosystem Roles

Many fruits (bananas, avocadoes, dates, mangoes, peaches, tequila) rely on C. brachyotis for seed dispersal. These bats may also play a role in plant pollination. (Schultes, 2003)

  • Ecosystem Impact
  • disperses seeds
  • pollinates

Economic Importance for Humans: Positive

Outside of the limited use of these bats as food, there is no direct economic benefit of this species for humans. However, because they are so important in dispersing seeds and pollinating plants, humans who rely on the plants these bats affect are indebted to the bats as well. (Nowak, 1997)

  • Positive Impacts
  • food

Economic Importance for Humans: Negative

Because of their frugivorous inclination, these bats can cause some crop damage.

  • Negative Impacts
  • crop pest

Conservation Status

Cynopterus brachyotis is not especially threatened.

Contributors

Allison Poor (editor), University of Michigan-Ann Arbor.

Nancy Shefferly (editor), Animal Diversity Web.

Kari Severson (author), Humboldt State University, Brian Arbogast (editor), Humboldt State University.

Glossary

acoustic

uses sound to communicate

altricial

young are born in a relatively underdeveloped state; they are unable to feed or care for themselves or locomote independently for a period of time after birth/hatching. In birds, naked and helpless after hatching.

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

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.

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

food

A substance that provides both nutrients and energy to a living thing.

frugivore

an animal that mainly eats fruit

herbivore

An animal that eats mainly plants or parts of plants.

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

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

polygynous

having more than one female as a mate at one time

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.

sedentary

remains in the same area

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.

solitary

lives alone

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.

year-round breeding

breeding takes place throughout the year

References

Andersen, K. 1912. Catalogue of the Chiroptera in the Collection of the British Museum: second edition. New York: Johnson Reprint Corporation.

Crichton, E., P. Krutzsch. 2000. Reproductive Biology of Bats. San Diego, CA: Academic Press.

Nowak, R. 1997. "Cynopterus" (On-line). Walker's Mammals of the World Online. Accessed November 16, 2001 at http://www.press.jhu.edu/books/walker_gone.html.

Richarz, K., A. Limbrunner. 1993. The World of Bats. Neptune City, NJ: TFH Publications, Inc..

Schultes, D. 2003. "The Malaysian Fruit Bat" (On-line). Animals at the Fort Worth Zoo. Accessed December 15, 2001 at http://www.whozoo.org/students/dansch/fruitbat.htm.