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 —only the Indian and great flying fox can weigh more. It has the longest documented forearm length of any bat species at .
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.
An early description of this species may be found in William Dampier's account of his circumnavigation, A New Voyage Round the World.
Taxonomy
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. The holotype had been collected on the Philippine island of Luzon during an expedition led by Otto von Kotzebue.
The genus Acerodon was described six years later in 1837, with A. jubatus as the type species for the new genus.
As of 2005, three subspecies of the giant golden-crowned flying fox are recognized:
- A. jubatus jubatus <small>(Eschscholtz, 1831)</small>
- A. jubatus mindanensis <small>(K. Andersen, 1909)</small>
- A. jubatus lucifer <small>(Elliot, 1896)</small>
A. jubatus lucifer had been described as Pteropus lucifer in 1896 by Daniel Giraud Elliot. 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. This publication was used by Mammal Species of the World
thumb|Illustration of giant golden-crowned flying fox skeleton
The giant golden-crowned flying fox is one of the largest bat species in the world. It is among the heaviest of all bat species, with individuals weighing up to . 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 and respectively. The wingspan of the Indian flying fox is up to , while the giant golden-crowned flying fox has a wingspan of .
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.
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. 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 to access sites on another island, Biliran. It forms harmonious mixed species colonies with another megabat, the large flying fox (Pteropus vampyrus). When time to leave the roosts for nightly foraging, the two species will head in the same direction. Based on limited observation, it is thought that females may not reach sexual maturity until two years of age. On Negros Island, females gave birth in April or May; based on other observations, females likely give birth during this time across its range. On the island of Maripipi, young were born in late May and June.
Predators, parasites, and disease
thumb|upright|One of the avian predators of the giant golden-crowned flying fox, the [[Philippine eagle]]
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.
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"). 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
Range and habitat
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. 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. Less than 10% of the original lowland forest cover now remains.
thumb|[[Subic Bay, Philippines]]
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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,
In 1995, 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.
Nationally, the species is protected by the 2001 Philippine Wildlife Resources Conservation and Protection Act, though this law is inadequately enforced.
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. 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.