Philippine Deforestation

Golden-Crowned Flying Fox
Acerodon jubatus

© 2002 (Photograph by J.S.H. Klompen)

The flying fox's slow, steady wingbeats can carry them at least 40 kilometers in a night.

As the late afternoon sun drops over the Sierra Madre mountains in northeastern Luzon, a group of huge trees nearly bare of leaves but supporting what seem to be very large, dark, oblong fruit undergoes a rapid and strange transformation. The "fruit," which have been swaying and shifting despite the absence of a breeze, give a shake and abruptly open huge wings. Hundreds, then thousands, then tens of thousands of bats begin to stretch, greeting their neighbors with harsh, squawking calls and clambering around the trees to their favorite spots for taking flight. With wingspans of five feet or more, and weighing 1,200 grams or more (about three pounds), these golden-crowned flying foxes (Acerodon jubatus) are probably the heaviest bats in the world. Living among them are another, similar species of large flying fox (Pteropus vampyrus) which weighs less but has an even greater wingspan. The entire group numbers perhaps 50,000 bats, which fly off in all directions in search of fruit. They may fly 40 kilometers or more each night looking for ripe figs, their favorite food.
Prior to World War I, colonies of giant fruit bats numbering from 50,000 to 150,000 were reported on every large island in the country. The largest islands had many such colonies; a reasonable guess for Mindanao would be more than 20, for a total of at least two million giant bats. These bats were an integral part of the lowland rain forest; the seeds in the fruit they ate traveled quickly through their digestive tracts, and were voided as they flew. The rain of seeds (complete with fertilizer) from the giant bats overhead was critical in maintaining ecological stability, since fig trees—whose seedlings can tolerate the harsh tropical sun—are important re-colonizers of land laid bare by fire, landslide, or volcanic eruption.
By the mid-1980s, widespread destruction of lowland rain forest had reduced the bats' habitat to a fraction of its original extent. The bats also were subject to heavy hunting of by impoverished subsistence farmers. Most colonies were entirely gone, and those known to still persist were down to a few thousand individuals at best. Survival seemed tenuous. But in the mid-1990s, researchers in the Sierra Madre wilderness found a new colony of 50,000 to 60,000 giant fruit bats—the best hope for the survival of one of the most remarkable mammals on earth.

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