Also called roundleaf bats, Old World leaf-nosed bats vary greatly in size. They have a combined head and body length that ranges from 1.1 to 4.3 inches (2.8 to 11 centimeters). One species, Commerson’s leaf-nosed bat, is one of the largest insect-eating bats of all the microchiroptera (my-kro-keer-OPter-ah; one of two bat categories that includes most of the bats in the world), with a wingspan of about 2 feet (0.6 meters).
These bats are closely related to and share many of the features of horseshoe bats. They have a fleshy fold of skin around their nostrils called a noseleaf, which is leaf-like in appearance. The lower part of the noseleaf is shaped like a horseshoe or U-shape, with leaf-like flaps of skin above that protrude outwards.
The ears of these bats vary in size. They do not have a tragus (TRAY-gus), a flap of skin in front of the ear opening, which is common in many bats. These bats have only two bones in each toe. Their tail length ranges from nothing to approximately 2.4 inches (6 centimeters). Fur color ranges widely among the species, from reddish and yellowish to brown and cream. In several species, males and females have different fur colors, as well as different body and noseleaf sizes.
Old World leaf-nosed bats are found in tropical (hot and humid weather) and subtropical areas of the Old World, meaning the part of the world made up of Australia, Africa, Asia, and Europe. They are found in Africa and southern Asia, east to the Philippine Islands, the Solomon Islands, and Australia.
WHERE DO BATS LIVE
These bats live in a range of habitats that include deserts and rainforests. They roost (settle or rest) in caves, underground openings, buildings, and hollow trees. One species, the fulvous (FUL-vus) leaf-nosed bat, has been found in burrows of a large porcupine in Africa.
WHAT DO BATS EAT
Old World leaf-nosed bats eat insects, although little is known about the specific insects that make up their diet.
BEHAVIOR AND REPRODUCTION
There is little information on the behavior and reproduction habits of many Old World leaf-nosed bat species. Most roost in groups that range widely in size: from about twelve to groups of hundreds, to approximately 5,000. Some species appear to roost singly. The primary roosting sites of these bats are caves and tunnels, yet many roost in tree hollows and buildings.
Old World leaf-nosed bats are nocturnal, or active at night, as are all bats. When they emerge from their roosts at night, they use echolocation (eck-oh-loh-KAY-shun) to forage, search, for food. Echolocation is the process of detecting objects by sending out sounds and listening to the sounds that bounce back from the objects. Old World leaf-nosed bats fly with their mouth closed and send out sounds through their nose, as opposed to most bats that use their mouths. These bats can send out sound in one frequency and listen to the sounds bounced back on another frequency.
Observations show they catch their prey in flight. Many hunt close to the ground, such as the Old World leaf-nosed bat of the Congo.
These bats mate during the fall and females do not become fertilized until the following year. Females generally give birth to a single offspring each year. When the offspring become independent and sexually mature depends upon the species and where they live.
OLD WORLD LEAF-NOSED BATS AND PEOPLE
These bats eat many insects that are considered pests to people. Some species have been harmed by humans destroying their habitat.
Some of the species in this family are common and others are rare and vulnerable to threats. Since little is known about many species in this family, the vulnerability of these bats is not fully understood. Out of the species that the IUCN lists, two are classified as Critically Endangered, facing an extremely high risk of extinction, dying out, in the wild; fifteen as Vulnerable facing a high risk of extinction, and twenty-three as Near Threatened, not currently threatened, but could become so.