With a wingspan of more than 1.5 meters, the large flying fox (Pteropus vampyrus) is the world's largest bat. But that size hasn't helped it. In fact, the giant fruit bat has become a target for hunting, and so many of them are being killed every year that the species now faces possible extinction, according to a new study.

The study, headed up by Jonathan H. Epstein of the Wildlife Trust in New York City, was published in the August 25 online edition of the Journal of Applied Ecology. It has been called the first study of its kind to examine fruit bats in Asia.

The large flying fox can be found in countries including Indonesia, Malaysia, Myanmar and Cambodia. In Malaysia alone, 22,000 bats are legally hunted every year, and an unknown number are also illegally killed. In a prepared statement, Epstein said that this level of hunting "is unsustainable for the number of bats in the country and will decimate this ecologically important species."

Regarding that ecological importance, Epstein told the BBC that the bats "eat fruit and nectar and in doing so they drop seeds around and pollinate trees. So they are critical to the propagation of rainforest plants."

The flying fox is currently listed as "near threatened" by the IUCN Red List of Threatened Species, which notes that the species is "in significant decline...because it is being overharvested for food over much of its range, and because of ongoing degradation of its primary forest habitat." IUCN research shows that the flying fox population has dropped "at a rate of probably less than 30 percent over 10 years."

Epstein and his team found that the bats travel great distances in search of food, and travel hundreds of kilometers between roosting sites. This often sends them across national borders. The species is protected in bordering Thailand, but hunting is permitted in other nearby countries.

Using computer models, Epstein says that the large flying fox could become extinct in as few as six years.

In order to save the species from extinction in Malaysia, Epstein and his colleagues are calling for a temporary hunting ban. According to the Wildlife Trust, "the Malaysian Department of National Parks and Wildlife participated in the research and is currently reviewing hunting policy in light of this study."

Image: Large flying fox (Pteropus vampyrus), via Wikipedia