Acerodon jubatus

Geographic Range

Acerodon jubatus is endemic to the Philippines, with the exceptions of the Palawan region and the Batanes and Babuyan island groups.

• Biogeographic Regions
• oriental oriental
  • native native

• Other Geographic Terms
• island endemic island endemic

Habitat

Acerodon jubatus roosts in hardwood trees, often on cliff edges or steep, inaccessible slopes. Other preferred roosting sites include bamboo clumps, mangrove trees, and other swampy forested areas. Roosting sites are usually located on small, offshore islands. Acerodon jubatus has been observed to use disturbed areas for roosting.

When foraging, Acerodon jubatus exhibits a strong preference for primary forest or high-quality secondary forest over disturbed habitat, and may fly long distances (up to 16 km) from its roost to reach these locations. There is also a preference for river margins, probably due to their particular plant communities. Acerodon jubatus is rarely found foraging in disturbed or agricultural areas, though it regularly crosses such areas while traveling between forested regions.

• Habitat Regions
• tropical tropical
• terrestrial terrestrial

• Terrestrial Biomes
• forest forest

• Wetlands
• swamp swamp

• Other Habitat Features
• riparian riparian

Physical Description

Like other bats in the Family Pteropodidae , Acerodon jubatus has large, bright eyes and relatively simple external ears with continuous margins. The ears are about as long as the muzzle and are pointed. There is a claw on the second digit of each wing. The skull has strong, incomplete postorbital processes, with supraorbital foramena. The teeth are sharp and pointed, except for the last two molars.

The fur of Acerodon jubatus is thin on the throat and ear membranes, absent on the wing membranes, and short and smooth on the body. There is considerable variation in color but the typical scheme is dark brown or black on the forehead and sides of the head, reddish brown on the shoulders, and a dark brown or black on the lower back and underside. The nape ranges from cream to golden yellow. There is a narrow line of orange at the back of the neck. Variable numbers of yellow hairs are scattered throughout the fur, especially on the lower body. Variation in color does not depend on age, sex, or locality.

The head and body length combined ranges from 178 to 290 mm; there is no tail. The forearm varies between 125 and 203 mm, and the wingspan varies between 1.51 and 1.7 m. Weights between 1050 and 1200 g have been reported, making Acerodon jubatus among the largest bats in the world. Males are larger and heavier than females.

• Other Physical Features
• endothermic endothermic
• homoiothermic
• bilateral symmetry bilateral symmetry

• Sexual Dimorphism
• male larger

Reproduction

No information is currently available on the mating system of Acerodon jubatus .

Acerodon jubatus populations on all islands reproduce at approximately the same time, indicating that they probably use photoperiod as a cue instead of more localized environmental conditions. Females give birth during April and May, and possibly early June. Females in captivity give birth only once every two years; those in the wild likely reproduce less often. Not much about litter size is known, but females have not been observed with more than one offspring at a time.

• Key Reproductive Features
• iteroparous iteroparous
• seasonal breeding seasonal breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual sexual
• viviparous viviparous

Females have been observed to carry a single offspring. The young cling to their mothers' fur with their claws, while the mothers fan them with one wing to keep them cool. Females invest significantly in their young through gestation and lactation.

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

Lifespan/Longevity

No information is currently available on longevity in Acerodon jubatus .

Behavior

Acerodon jubatus individuals roost with other bat species, especially Pteropus vampyrus and occasionally Pteropus hypomelanus . They are typically outnumbered by these other species, making up less than 20% of the total roost population. Mixed colonies of 100,000 to 150,000 individuals were reported in the early 1900s to 1920s; recently, however, no colonies over 30,000 individuals have been observed, and many are no larger than 5,000 individuals. Bats emerge from the colony at sunset, fly into the mountains to feed on fruit, and return before sunrise.

• Key Behaviors
• flies
• nocturnal nocturnal
• motile motile
• sedentary sedentary
• social social
• colonial colonial

Home Range

Home range sizes for golden-capped fruit bats are not known.

Communication and Perception

Acerodon jubatus individuals have large eyes and may use visual cues in communication. They have a distinctive odor, suggesting olfactory communication, but no specific scent glands have been identified.

• Communication Channels
• visual visual
• chemical chemical

• Perception Channels
• visual visual
• tactile tactile
• acoustic acoustic
• chemical chemical

Food Habits

Golden-capped fruit bats are frugivores. Figs ( Ficus ) appear to be a dietary staple, as fig seeds compose 41% of droppings on average. Ficus subcordata is the most commonly eaten species, though Acerodon jubatus also shows a strong preference for fruits from other Ficus species and, to a lesser extent, Ficus variegata . Not every fig species is used, and the dietary range is narrower than other bats in the same area. Notably, these staple plants are only found in mature lowland forests, making golden-capped fruit bats forest obligates. They also consume leaves by crushing them and swallowing the liquid content, but how much of the diet is composed of leaves is unknown.

• Primary Diet
• herbivore herbivore
  • frugivore frugivore

• Plant Foods
• leaves
• fruit

Predation

There are no known predators of Acerodon jubatus .

Ecosystem Roles

Golden-capped fruit bats, as frugivores, are distributors of plant seeds. The impact of such distribution on the local ecosystem has not been recorded.

• Ecosystem Impact
• disperses seeds

Economic Importance for Humans: Positive

Some large bat roosts, shared by Acerodon jubatus and other species, are used as tourist attractions.

Golden-capped fruit bats are hunted for consumption. They are also occasionally captured live for exportation, though this is uncommon because they are said to have an unpleasant smell compared to other, similar bats. These practices have contributed to the species's endangered status.

• Positive Impacts
• pet trade pet trade
• food food
• ecotourism ecotourism

Economic Importance for Humans: Negative

There are no known adverse effects of Acerodon jubatus on humans.

Conservation Status

Golden-capped fruit bats are listed as endangered by the IUCN and appear in Appendix I of CITES. Populations are experiencing severe declines due to habitat loss from logging and farming projects and hunting for meat or trade. They are particularly susceptible to habitat loss because of their dependence on fig trees found only in mature old-growth forest. This species is protected, with three large roost sites entirely exempt from hunting, but the bats are still hunted while foraging away from the roosts. The population is estimated at about 10,000 individuals; this represents a 50% decline over the last 30 years. The decline is predicted to continue unless destruction of old-growth forest ceases. Populations now recognized as A. jubatus ( Acerodon lucifer ) are now extinct.

Other Comments

This species now includes Panay golden-crowned flying foxes, Acerodon lucifer , which was once considered a separate species. There appear to be no morphological differences to distinguish the two taxa. It is not known whether they are behaviorally identical, and this will probably never be determined because the Panay population appears to be extinct.

Additional Links

Encyclopedia of Life

Contributors

Virginia Heinen (author), Michigan State University, Barbara Lundrigan (editor, instructor), Michigan State University, Tanya Dewey (editor), Animal Diversity Web.

References

Heaney, L., P. Heideman. 1987. Philippine Fruit Bats: Endangered and Extinct. BATS Magazine , 5(1): 3-5. Accessed March 05, 2009 at http://www.batcon.org/index.php/education/article-and-information/bats-magazine.html?task=viewArticle&magArticleID=276 .

Heideman, P. 1987. The Reproductive Ecology of a Community of Philippine Fruit Bats (Pteropodidae, Megachiroptera) . Ann Arbor, MI: University Microfilms International. Accessed March 09, 2009 at http://p2047-ezproxy.msu.edu.proxy2.cl.msu.edu/login?url=http://proquest.umi.com.proxy2.cl.msu.edu/pqdweb?did=753014291&sid=1&Fmt=2&clientId=3552&RQT=309&VName=PQD .

Ingle, N., L. Heaney. 1992. A key to the bats of the Philippine Islands . Chicago, IL: Field Museum of Natural History. Accessed March 06, 2009 at http://www.archive.org/details/keytobatsofphili69ingl .

Mildenstein, T., A. Cariño, S. Paul, L. Heaney, P. Alviola, A. Duya, S. Stier, S. Pedregosa, R. Lorica, N. Ingle, D. Balete, J. Garcia, J. Gonzalez, P. Ong, G. Rosell-Ambal, B. Tabaranza. 2008. "IUCN 2008 Red List: Acerodon jubatus" (On-line). 2008 IUCN Red List of Threatened Species. Accessed March 05, 2009 at http://www.iucnredlist.org/details/139 .

Mildenstein, T., S. Steir, C. Nuevo-Diego, L. Mills. 2005. Habitat selection of endangered and endemic large flying-foxes in Subic Bay, Philippines. Biological Conservation , 126(1): 93-102.

Mudar, K., M. Allen. 1986. A list of bats from northeastern Luzon, Philippines. Mammalia , 50(2): 219-225.

Nowak, R. 1991. Walker's Bats of the World . Baltimore & London: Johns Hopkins University Press.

Stier, S., T. Mildenstein. 2005. Dietary Habits of the World's Largest Bats: The Phillipine Flying Foxes, Acerodon Jubatus and Pteropus Vampyrus Lanensis. Journal of Mammology , 86(4): 719-729.

Taylor, E. 1934. Philippine Land Mammals . Manila, Philippine Islands: Monographs of the Bureau of Science.

Wilson, D., D. Reeder. 2005. Mammal Species of the World. A Taxanomic and Geographic Reference (3rd ed) . Baltimore: Johns Hopkins University Press.

2008. "Appendices I, II, and III" (On-line). Convention on International Trade in Endangered Species of Wild Fauna and Flora. Accessed March 05, 2009 at http://www.cites.org/eng/app/appendices.shtml .