Bats of the genus Pteropus, belonging to the megabat suborder, Megachiroptera, are the largest bats in the world. They are commonly known as the fruit bats or flying foxes among other colloquial names. They live in the tropics and subtropics of Asia (including the Indian subcontinent), Australia, islands off East Africa (but not mainland Africa), and a number of remote oceanic islands in both the Indian and Pacific Oceans. There are at least 60 extant species in this genus.
The oldest ancestors of the genus Pteropus to be unearthed appear in the fossil record almost exactly as they are today, the only notable differences being early flight adaptations such as a tail for stabilizing. The oldest megachiropteran is dated at around 35 million years ago, but the preceding gap in the fossil record makes their true lineage unknown.
Characteristically, all species of flying foxes only feed on nectar, blossom, pollen, and fruit, which explains their limited tropical distribution. They do not possess echolocation, a feature which helps the other suborder of bats, the microbats, locate and catch prey such as insects in mid-air. Instead, smell and eyesight are very well-developed in flying foxes. Feeding ranges can reach up to 40 miles. When it locates food, the flying fox "crashes" into foliage and grabs for it. It may also attempt to catch hold of a branch with its hind feet, then swing upside down – once attached and hanging, the fox draws food to its mouth with one of its hind feet or with the clawed thumbs at the top of its wings.
Many species are threatened today with extinction, and in particular in the Pacific, a number of species have died out as a result of overharvesting for human consumption. In the Marianas, flying fox meat is considered a delicacy, which led to a large commercial trade. In 1989, all species of Pteropus were placed on Appendix II of Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) and at least seven on Appendix I, which restricts international trade. The subspecies P. hypomelanus maris of the Maldives is considered endangered due to limited distribution and excessive culling. The commerce in fruit bats continues either illegally or because of inadequate restrictions. Local farmers may also attack the bats because they feed in their plantations, and in some cultures, their meat is believed to cure asthma. Nonhuman predators include birds of prey, snakes, and other mammals.
The large flying fox (P. vampyrus) is generally reported as the largest Pteropus, but a few other species may match it, at least in some measurements. The large flying fox has a wingspan up to 1.5 m (4 ft 11 in) and five individuals weighed 0.65–1.1 kg (1.4–2.4 lb). Even greater weights, up to 1.6 kg (3.5 lb) and 1.45 kg (3.2 lb), have been reported for the Indian flying fox and great flying fox (P. neohibernicus), respectively. The black-bearded flying fox (P. melanopogon) is massive and may be heavier than all other megabats, but exact weight data are not available. Comparably, no full wingspan measurements are available for the great flying fox (P. neohibernicus), but with a forearm length up to 206 mm (8.1 in), it may even surpass the large flying fox (P. vampyrus) where the forearm is up to 200 mm (7.9 in). Outside this genus, the giant golden-crowned flying fox (Acerodon jubatus) is the only bat with similar dimensions.
Most flying fox species are considerably smaller and generally weigh less than 600 g (21 oz). The smallest, the masked flying fox (P. personatus), Temminck's flying fox (P. temminckii), Guam flying fox (P. tokudae) and dwarf flying fox (P. woodfordi), all weigh less than 170 g (6.0 oz).
The pelage is long and silky with a dense underfur. No tail is present. As the name suggests, the head resembles that of a small fox because of the small ears and large eyes. Females have one pair of mammae located in the chest region. Ears are simple (long and pointed) with the outer margin forming an unbroken ring (a defining characteristic of megabats). The toes have sharp, curved claws.
Some scientists have proposed that flying foxes are descended from primates rather than bats and that mammalian flight ability has evolved more than once. This theory is not accepted by most modern zoologists. For more details see: Flying primates theory.
Genus Pteropus – flying foxes
- P. alecto species group
- P. caniceps species group
- P. chrysoproctus species group
- P. conspicillatus species group
- P. livingstonii species group
- P. mariannus species group
- P. melanotus species group
- P. molossinus species group
- P. neohibernicus species group
- P. niger species group
- P. personatus species group
- P. poliocephalus species group
- P. pselaphon species group
- Chuuk flying fox, P. insularis
- Temotu flying fox, P. nitendiensis
- Large Palau flying fox, P. pilosus (19th century †)
- Bonin flying fox, P. pselaphon
- Guam flying fox, P. tokudae (1970s †)
- Insular flying fox, P. tonganus
- Vanikoro flying fox, P. tuberculatus (†? early 20th century)
- New Caledonia flying fox, P. vetulus
- P. samoensis species group
- P. scapulatus species group
- P. subniger species group
- Admiralty flying fox, P. admiralitatum
- Dusky flying fox, P. brunneus (19th century †)
- Ryukyu flying fox, P. dasymallus
- Nicobar flying fox, P. faunulus
- Gray flying fox, P. griseus
- Ontong Java flying fox, P. howensis
- Small flying fox, P. hypomelanus
- Ornate flying fox, P. ornatus
- Little golden-mantled flying fox, P. pumilus
- Philippine gray flying fox, P. speciosus
- Small Mauritian flying fox, P. subniger (19th century †)
- P. vampyrus species group
- incertae sedis
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