There are no known predators of Acerodon jubatus.
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.
Range mass: 1050 to 1200 g.
Range length: 178 to 290 mm.
Range wingspan: 1.51 to 1.7 m.
Other Physical Features: endothermic ; homoiothermic; bilateral symmetry
Sexual Dimorphism: male larger
No information is currently available on longevity in Acerodon jubatus.
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.
Range elevation: 0 to 1100 m.
Habitat Regions: tropical ; terrestrial
Terrestrial Biomes: forest
Wetlands: swamp
Other Habitat Features: riparian
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.
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 ; chemical
Perception Channels: visual ; tactile ; acoustic ; chemical
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.
US Federal List: no special status
CITES: appendix i
IUCN Red List of Threatened Species: endangered
There are no known adverse effects of Acerodon jubatus on humans.
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 ; food ; ecotourism
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
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.
Plant Foods: leaves; fruit
Primary Diet: herbivore (Frugivore )
Acerodon jubatus is endemic to the Philippines, with the exceptions of the Palawan region and the Batanes and Babuyan island groups.
Biogeographic Regions: oriental (Native )
Other Geographic Terms: island endemic
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.
Breeding interval: Females can breed as often as once every two years.
Breeding season: Births occur from April to June, but gestation periods are unknown, so the breeding season has yet to be determined
Average number of offspring: 1.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; 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 ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Female); pre-weaning/fledging (Provisioning: Female, Protecting: Female)
The giant golden-crowned flying fox (Acerodon jubatus), also known as the golden-capped fruit bat, is a species of megabat endemic to the Philippines. Since its description in 1831, three subspecies of the giant golden-crowned flying fox have been recognized, one of which is extinct. The extinct subspecies (A. jubatus lucifer) was formerly recognized as a full species, the Panay golden-crowned flying fox. Formerly, this species was placed in the genus Pteropus; while it is no longer within the genus, it has many physical similarities to Pteropus megabats. It is one of the largest bat species in the world, weighing up to 1.4 kg (3.1 lb)—only the Indian and great flying fox can weigh more. It has the longest documented forearm length of any bat species at 21 cm (8.3 in).
It is primarily frugivorous, consuming several kinds of fig and some leaves. It forages at night and sleeps during the day in tree roosts. These roosts can consist of thousands of individuals, often including another species, the large flying fox. Not much is known about its reproduction; it gives birth annually from April through June, with females having one pup at a time. Predators of the giant golden-crowned flying fox include raptors such as eagles, the reticulated python, and humans.
Owing to deforestation and poaching for bushmeat, it is an endangered species. Though national and international law makes hunting and trade of this species illegal, these regulations are inadequately enforced, meaning that the species is frequently hunted nonetheless. Even in roosts that are more stringently protected from poaching, it is still affected by human disturbance via tourists who intentionally disturb them during the day.
The giant golden-crowned flying fox was described as a new species in 1831 by German naturalist Johann Friedrich von Eschscholtz. Eschscholtz placed it in the genus Pteropus with a scientific name of Pteropus jubatus.[3] Its species name "jubatus" is from Latin, meaning "having a mane or crest, crested".[4] The holotype had been collected on the Philippine island of Luzon during an expedition led by Otto von Kotzebue.[3] The genus Acerodon was described six years later in 1837, with A. jubatus as the type species for the new genus.[5] As of 2005, three subspecies of the giant golden-crowned flying fox are recognized:[6]
A. jubatus lucifer had been described as Pteropus lucifer in 1896 by Daniel Giraud Elliot.[8] A. jubatus lucifer, commonly the Panay golden-crowned flying fox, is still sometimes considered an extinct species of megabat. A 1998 publication noted that there were no morphological differences that distinguish A. jubatus lucifer from A. jubatus.[9] This publication was used by Mammal Species of the World[6] and the IUCN as justification as listing A. jubatus lucifer as a subspecies of A. jubatus rather than as a full species.[1]
Overall, the giant golden-crowned flying fox is similar in appearance to many Pteropus species. It is different in its smaller canine teeth and its larger and more complex molars and premolars. Its upper incisors are slightly longer than Pteropus species, as well as sharper. Its four lower incisors have a greater disparity in length between the inner and outer pair than do Pteropus.[5] Its dental formula is 2.1.3.22.1.3.3 for a total of 34 teeth.[10]
The giant golden-crowned flying fox is one of the largest bat species in the world.[11] It is among the heaviest of all bat species, with individuals weighing up to 1.40 kg (3.1 lb). The only bat species known to weigh more than the giant golden-crowned flying fox are the Indian flying fox (Pteropus medius) and great flying fox (Pteropus neohibernicus), with a maximum weight of 1.6 kg (3.5 lb) and 1.45 kg (3.2 lb) respectively.[11][12] It has the longest forearm length of any species, measuring up to 215 mm (8.5 in). The great flying fox has a slightly shorter forearm length, and its wingspan is thus presumed to be lesser as well.[12] The wingspan of the Indian flying fox is up to 1.5 m (4.9 ft),[13] while the giant golden-crowned flying fox has a wingspan of 1.5–1.7 m (4.9–5.6 ft).[11] This species is somewhat dimorphic, with males slightly larger than females in many cranial and external measurements.[14]
The giant golden-crowned flying fox gets its common name from its fur coloration. It has golden coloration that begins between its eyes and terminates to a narrow "V" shape at the nape of its neck, though sometimes extending to the upper shoulders.[15] The sides of its face, brows, and throat are black, while the sides of its neck and upper back are maroon; this maroon fur transitions into brownish black, which then grades into reddish brown down the back. On its ventral (belly) side, its fur is generally black, though the front of the neck may have a maroon tinge and its belly may be interspersed with yellow hairs. Its hindlimbs are covered with brownish black fur, and its flight membranes are pale brown.[10]
The giant golden-crowned flying fox is largely frugivorous, though it also consumes plant leaves (folivorous). One study found that it is particularly dependent on Ficus fruits (figs), with Ficus seeds found in 79% of all fecal pellets. Especially common Ficus seeds were from the Urostigma subgenus (which includes Ficus species commonly referred to as banyan), as well as Ficus variegata.[16]
The results support that the primary food group is composed of fig species, including Ficus subcordata and unidentified leaves. There is a lack of consensus on whether items found frequently in the fecal samples are actually prioritized or found as an alternative food for these bats.[16]
Multiple types of figs can also contribute to different nutrients for the species. Frugivorous bats usually do not consume foods rich in protein. The overconsumption of fruits, paired with leaves may contribute to an adequate amount of protein in their diet. Figs are superior sources of calcium, which may also aid in their growth to adults.[16]
Like nearly all megabats, giant golden-crowned flying foxes cannot echolocate, and thus rely on sight to navigate.[17] This species likely commutes long distances between its roost and foraging grounds. Individuals who roosted on the island of Maripipi, for example, were documented traveling more than 12 km (7.5 mi) to access sites on another island, Biliran.[18]
Giant golden-crowned flying foxes are nocturnal, sleeping for most of the day. They do engage in some social and maintenance behaviors during the day at times, with solitary behaviors such as self-grooming, excreting waste, and wing flapping more prevalent in the afternoon and social behaviors such as fighting and mating in the morning.[19] It forms harmonious mixed species colonies with another megabat, the large flying fox (Pteropus vampyrus).[20] When time to leave the roosts for nightly foraging, the two species will head in the same direction.[20] In the 1920s, colonies of these two species would number as many as 120,000 individuals. As of 1992, the largest of these colonies was 5,000; many comprised only several hundred individuals.[18]
Little is known about mating and reproduction of the giant golden-crowned flying fox.
The litter size is one individual, with females likely producing no more than one litter per year.[18] It has also been speculated that females may only give birth every other year.[21] Based on limited observation, it is thought that females may not reach sexual maturity until two years of age.[14] On Negros Island, females gave birth in April or May; based on other observations, females likely give birth during this time across its range.[18] On the island of Maripipi, young were born in late May and June.[14] This species show signs of a Type II survivorship curve. Parents take effort into the survivability of the offspring to ensure maturity and independent growth. This species may live up to 13–30 years in the wild.[22] Although they typically live a long life in the wild, they are also hunted by humans and other apex predators such as the Philippine eagle. They may also be susceptible to wildlife diseases.[23]
The giant golden-crowned flying fox is impacted by ectoparasites (external parasites) including Cyclopodia horsfieldi, which is a species of fly in the family Nycteribiidae ("bat flies").[24] It is preyed on by several raptors including the Philippine eagle, white-bellied sea eagle, and possibly the Brahminy kite. Non-avian predators include the reticulated python[21] and humans.[1]
Like many bat species, the giant golden-crowned flying fox has been investigated as a source of emerging infectious disease. One study tested for the presence Reston virus, a kind of Ebolavirus that affects some primates (though not humans), in a population of giant golden-crowned flying foxes at Subic Bay. Of fifty-six individuals tested for Reston virus, three were seropositive, meaning that they tested positive for antibodies against the virus.[25]
The giant golden-crowned flying fox is endemic to the Philippines; it was the first endemic species of that country to be described, which it was in 1831.[16] Surveys reported in 2005 and 2011 documented this species on the islands of Bohol, Boracay, Cebu, Leyte, Luzon, Mindanao, Mindoro, Negros and Polillo. It was formerly found on the island of Panay, though this population has been extirpated.[1]
It is a forest specialist, occurring mostly at elevations from sea level to 1,100 m (3,600 ft).[1] It prefers areas uninhabited by humans. A 2005 study found none in inhabited areas.[26] The same study also revealed that these bats use river corridors called riparian zones more than originally thought, because the fig trees located near rivers are the bats' main source of food. They like to be close to agricultural fields, but only in undisturbed forest areas.[26]
As of 2016, the giant golden-crowned flying fox is listed as an endangered species by the IUCN. It meets the criteria for this designation because its population likely declined by more than 50% from 1986–2016. One of the largest factors in its decline is hunting for bushmeat.[1] Its large body size means that it is an easier target than many other bats. The practice of shooting the giant golden-crowned flying fox at its roosts results in excessive mortality, as dead individuals may not fall from the tree, and wounded individuals may glide some distance before falling. Therefore, a poacher may kill as many as thirty bats to recover ten.[18]
The giant golden-crowned flying fox is threatened by deforestation and has completely disappeared from many islands in the Philippines, such as Panay and most of Cebu.[1] Since 1900 the total forest coverage of the Philippines has been reduced from 70% to 20%.[27] Less than 10% of the original lowland forest cover now remains.[26] Negros, an island part of its range, retains only 4% of its original forest coverage.[28]
Internationally, the giant golden-crowned flying fox is protected by the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). In 1990,[1] two of the three subspecies (A. j. lucifer and A. j. mindanensis) were included on CITES Appendix II, meaning that trade of the taxa was strictly regulated.[29] In 1995,[1][30] the species was placed CITES Appendix I. Appendix I is stricter than Appendix II, meaning that commercial trade of the species is only legal in exceptional circumstances.[31] Nationally, the species is protected by the 2001 Philippine Wildlife Resources Conservation and Protection Act, though this law is inadequately enforced.[1]
While the majority of its roosts are within protected areas, illegal hunting occurs at a wide scale even within such areas. Three are largely protected in practice. On the island of Boracay, local landowners protect the roost from hunting disturbance. The local governments of Subic Bay and Mambukal protect another two roosts. Even though hunting pressures are lessened at these three roosts, the giant golden-crowned flying fox contends with other sources of disturbance. Tourists and their guides deliberately disturb the bats by clapping their hands or rapping on tree trunks to make the bats fly. In addition to keeping the bats from sleeping, these behaviors result in the separation of offspring from their mothers.[1]
In 2013, Bat Conservation International (BCI) listed this species as one of the 35 species of its worldwide priority list of conservation.[32] Actions that BCI has taken to promote its conservation include partnering with local non-governmental organizations (NGOs) to protect its roosts, as well as educate Filipinos about bats.[33] Some captive breeding programs exist for the species, though it is uncertain if they are sufficient to make up for population declines seen in the wild.[1]
The giant golden-crowned flying fox (Acerodon jubatus), also known as the golden-capped fruit bat, is a species of megabat endemic to the Philippines. Since its description in 1831, three subspecies of the giant golden-crowned flying fox have been recognized, one of which is extinct. The extinct subspecies (A. jubatus lucifer) was formerly recognized as a full species, the Panay golden-crowned flying fox. Formerly, this species was placed in the genus Pteropus; while it is no longer within the genus, it has many physical similarities to Pteropus megabats. It is one of the largest bat species in the world, weighing up to 1.4 kg (3.1 lb)—only the Indian and great flying fox can weigh more. It has the longest documented forearm length of any bat species at 21 cm (8.3 in).
It is primarily frugivorous, consuming several kinds of fig and some leaves. It forages at night and sleeps during the day in tree roosts. These roosts can consist of thousands of individuals, often including another species, the large flying fox. Not much is known about its reproduction; it gives birth annually from April through June, with females having one pup at a time. Predators of the giant golden-crowned flying fox include raptors such as eagles, the reticulated python, and humans.
Owing to deforestation and poaching for bushmeat, it is an endangered species. Though national and international law makes hunting and trade of this species illegal, these regulations are inadequately enforced, meaning that the species is frequently hunted nonetheless. Even in roosts that are more stringently protected from poaching, it is still affected by human disturbance via tourists who intentionally disturb them during the day.