The Large or Malayan Flying Fox and Some Interesting Bat Facts
The Impressive Flying Fox
Flying foxes are fascinating bats. As their name suggests, they look somewhat like foxes that have developed wings and taken to the air. They have pointed, fox-like faces with large eyes and small ears. The large or Malayan flying fox of Southeast Asia is a giant of the bat world and has a wingspan of up to six feet. In North America, the term "flying fox" often refers to this animal.
Flying foxes belong to the Order Chiroptera (like other bats) and the family Pteropodidae. At least 170 species exist. The number depends on the classification scheme that's used. The animals are also known as fruit bats, since their diet consists of fruits and other plant parts, and as megabats, since their family contains the largest bats in the world. Not all megabats are large, however. The other category of bats (the microbats) use echolocation to hunt for their prey. Megabats use their excellent senses of sight and smell to help them find food.
The large or Malayan flying fox (Pteropus vampyrus) is often considered to be the largest bat in the world, although sometimes other members of its group are given this honour. Its population is classified as Near Threatened by the International Union for Conservation of Nature, or the IUCN. In some parts of the animal's distribution, its numbers are decreasing rapidly due to hunting and habitat loss.
Mammals That Can Fly
Like other mammals, including humans, bats have hair on their body and make milk for their young. Bats are the only mammals that can fly, however. Other mammals that appear to fly, such as flying squirrels, actually glide. Bats flap their wings to propel themselves through the air. The wings are made of webs of skin supported by hand, arm, and leg bones. Bats either have no tail or have a tiny, non-functional remnant of one.
Most bats are nocturnal. They sleep in a protected place during the day and become active at night. Microbats are able to carry out a process called echolocation, which helps them find their prey. Most of these bats eat insects. When they're hunting, they emit ultrasonic sound waves though their nose or mouth. "Ultrasonic" sounds are too high for us to hear. The sound waves bounce off the prey and return to the bats, enabling them to detect the presence and position of the prey. In general, megabats can't echolocate. A few species use a simple type of echolocation to help them navigate in the dark, however.
Skeleton and Wings
A bat's skeleton has some special adaptations to allow the animal to fly. The thin arm bones bend at the elbows and end in very long and skinny finger bones. The arms and the fingers support a membrane made of skin, which forms a wing.
The thumb is shorter than the other fingers and is free of wing. A curved claw is present at the tip of each thumb. This claw enables the bat to grab hold of supporting objects as it climbs or travels around with its wings closed.
The wings extend to the back legs. The feet have clawed toes, which help the bat move and are used to cling to a support when the animal is hanging upside down. Often a bat hangs by just one foot. The knees point backwards when they're bent. Some bats move rather clumsily on land, but all are graceful fliers.
Bat Roosts and Camps
Most bats hunt for their food during the night and sleep in their roost during the day. A roost is a place where bats live. Common sites for roosts are caves, but the animals also collect in tree canopies and cavities, under bridges or roofs, in abandoned mines, basements, or attics, in rock crevices, and in wall cavities. When many bats use the same roost, the area is sometimes called a camp.
The little red flying fox of Australia has been known to form camps containing over a million bats. As the animals stream out of the camp, they create a very impressive sight. Large roosts containing many bats are thought to provide benefits such as increased warmth in the roost, better protection of the babies, and predator confusion created by a huge number of animals flying at the same time.
The Large, Malayan, or Malaysian Flying Fox
The large flying fox is found throughout Southeast Asia in forests and mangroves. Its wings are made of two layers of skin. The wingspan is usually about five feet but sometimes reaches an amazing width of six feet. The bat weighs up to 2.4 pounds.
The animal has large eyes, pointed ears, and no tail. It's usually black, brown, red brown, or orange brown in colour. The chest may be bright orange, however, and the area between the shoulders may be either orange or yellow. The hair on the bat's back is short and quite stiff, while the hair on its undersurface is longer and woolly.
Geographic Range: Vietnam, Burma, Malaysian Peninsula, Borneo, Philippines, Sumatra, Java, and Lesser Sunda Islands, adjacent small islands including Anak Krakatau— Oakland Zoo (with respect to Pteropus vampyrus)
Diet of the Large or Malayan Flying Fox
Although the species name of the large flying fox ("vampyrus") may remind people of blood-drinking vampire bats, the animal eats plants. It doesn't eat animals or their blood. The bat is nocturnal and forages for fruit at night, starting at sunset and returning at dawn. It also eats flowers, pollen, and nectar. It has a long tongue, which helps it reach the nectar inside a flower. Its teeth are adapted to cut through the tough outer covering of fruits.
The animal plays an important role in its ecosystem. Flower pollen may become trapped on the bat's fur as it feeds and then fall off when the animal visits another flower. In this way, the bat acts as a pollinator.
The animal also helps to distribute the seeds of fruits. It squeezes fruits in its mouth to extract the juice and then spits out the dried pulp and the seeds. Since bats may carry fruit to a new area before they eat it, the seeds can germinate far away from their parent flower. Any seeds that are swallowed pass through the bat's digestive tract unharmed and are released into a new habitat in its feces.
Large flying foxes may fly more than thirty miles from their roost in order to find food. Unfortunately, they sometimes visit cultivated fruit trees to feed, which brings them into conflict with humans.
During the day, the large flying fox roosts in large communities in the tree tops. There are hundreds or even thousands of the animals in most roosts. The branches in the area are stripped of their leaves and bark by the bats' claws. The animals sometimes compete for the best place to hang. They may spread their wings, strike other bats with their thumb claws, and growl or shriek to express territoriality. Flying foxes produce a variety of vocalizations and can be very noisy, especially when feeding.
The bats sleep with their wings wrapped around their body. If they get too hot they open their wings to fan themselves. They may also lick their fur so that the evaporation of saliva cools them down. They may occasionally leave the roost for a short flight. When they need to defecate or urinate, they turn upside down (from their point of view). They hang on to their support with their thumbs instead of their toes so that the waste falls to the ground and not on to their bodies.
Reproduction and Lifespan
A male large flying fox mates with several females. The gestation period is five or six months. Usually only one baby is born per female. Occasionally, twins are produced. The babies, or pups, have light hair, which darkens as they mature. Females in a group produce their pups at the same time.
The young pup attaches itself to its mother's chest and is carried around by her, even while she's flying. After the first few days of its life, however, the mother leaves her pup in the roost while she forages for food. The pups suckle for two to three months. The animals seem to live for about fifteen years in the wild. They have lived for as long as thirty years in captivity.
The IUCN Red List
The IUCN monitors the populations of flying foxes and other animals. It maintains a database of animal species—the Red List—and uses the categories listed below to classify the population status of each species.
In general, the categories range from the least serious state to the most serious. The Not Evaluated and Data Deficient categories might mean that a population is in trouble, however, since the number of animals hasn't been assessed. The large flying fox is classified in the Near Threatened category.
- Not Evaluated
- Data Deficient
- Least Concern
- Near Threatened
- Critically Endangered
- Extinct in the Wild
Population Status of the Large Flying Fox
The large flying fox faces a number of problems. In many places, its forest habitat is being cleared for human use. In some areas it's treated as an agricultural pest and is shot or poisoned. It's widely hunted for food and sport, often legally. Sometimes it's hunted illegally, however. The bat is also killed for its fat, which is used in traditional medicine.
Laws protecting the bat exist in some parts of its range, but they aren't always enforced. The animal flies long distances during foraging and during migration to new roosts. It often travels over national boundaries, so international laws are needed.
The IUCN says that although the status of the large flying fox population is Near Threatened at the moment, the animal's population is decreasing and the species is close to Vulnerable in status. Unfortunately, the organization's last population assessment was performed in 2008. A new one is badly needed so that appropriate decisions can be made with respect to the animal's future.
Some conservationists think that in certain parts of its range the bat could become extinct within the lifetimes of people living today. We need to know whether this is likely and if possible take steps to prevent the extinction. It would be a great shame if this magnificent animal disappeared from the Earth.
- Information about the Chiroptera from the University of California Museum of Paleontology
- Large Flying Fox facts from Thai National Parks
- Information about the Malayan Flying Fox from the National Aviary
- More facts about Pteropus vampyrus from the Oakland Zoo
- Pteropus vampyrus entry on the Red List of the International Union for Conservation of Nature
© 2013 Linda Crampton