Bat Boy

Natural History, Oct, 2001 by Richard Milner

The world's 925 or so species of bats fall into two suborders. In the Americas, we are moat familiar with the larger group, whose members are small and employ echolocation to catch flying insects. The other suborder comprises the largest-bodied flying mammals, including flying foxes. All strictly plant eaters, the sixty kinds of flying foxes are found mainly in India, mainland Southeast Asia, the islands of Indonesia, and Australia. Instead of using sonar when foraging at night, they rely on their excellent vision to find fruits and blossoms. In Australia, hundreds of thousands of flying foxes, often members of several species, congregate daily at arboreal "bat camps" After hanging upside down all day--squawking, grooming, and nursing their young--they take wing at night to seek food.

This male little red flying fox ("little" is part of its common name) is grooming its wings while hanging among hundreds of other bats in a eucalyptus tree near Brisbane, on Australia's east coast. Formerly dependent on the once-widespread eucalyptus forests, flying foxes now settle near farms and urban areas, where they incur the wrath and vengeance of farmers and homeowners by eating fruit from gardens and orchards.

As the only mammals capable of sustained flight, bats rely on their semitransparent wings, composed of two layers of hairless skin stretched between the bones of their elongated forelimbs and those of their short hind limbs. Licking the wings is part of a daily routine. While grooming, the male flying fox keeps his genitals exposed, indicating to nearby females that he is receptive to mating. When his wings are spotless, he will coat them with an oily substance (produced by glands in his nose) that helps keep the membranes flexible and waterproof.