Bonin fruit bat, Ogasawara giant bat
The Bonin flying fox, Bonin fruit bat (Pteropus pselaphon ), or in Japanese Ogasawara giant bat (オガサワラオオコウモリ, Ogasawara ōkōmori) is a species of flying fox in the family Pteropodidae. It is endemic to four islands (Chichijima, Hahajima, North Iwo Jima, and South Iwo Jima) in Ogasawara Islands, Japan. Its natural habitat is subtropical forests. It is threatened by habitat loss.
The Bonin flying fox was described by British naturalist George Tradescant Lay in 1829.He gave it the species name pselaphon as a reference to "the habit of feeling instead of seeing its way in the day time." Pselaphon is a New Latin word from Ancient Greek psēlaphan' 'to grope about'.
Their fur is predominantly black and brown, with silver-tipped hairs interspersed.Their uropatagium is almost completely furred across the dorsal side, but about half furred on its ventral side.The fur along the body is smooth but is frizzled around the head, neck, and shoulders.They have scroll-like nostrils.From their nose to the tip of the uropatagium, they are 254 mm (10.0 in) long.Their wingspan is 787 mm (31.0 in).Their forearms are 132–143 mm (5.2–5.6 in) long. They weigh 403–587 g (14.2–20.7 oz).Young bats (pups) have forearm lengths of less than 125 mm (4.9 in).In captivity, they can live at least 16 years.
It is one of the northernmost species of flying foxes. It is endemic to the Bonin Islands of Japan, including Chichijima and Hahajima; and the Iwo Islands, including North Iwo Jima, Iwo Jima, and South Iwo Jima.They live in subtropical habitat. The islands where they are found have many steep hills
When foraging, they move slowly through the trees.In the summer, individuals roost alone rather than in colonies.In the winter, their colonies form unique, ball-shaped dense clusters during the daytime to conserve body heat.Their winter colonies can have as many as 100 individuals. Bonin flying foxes do not have a strong fear of humans.Bonin flying foxes are an animal species known to display homosexual behavior, with males observed performing fellatio on other males. This behavior occurs independently of social grooming, and one possible explanation for it is that it promotes colony formation for warmth among males who would otherwise repel each other during competition for females.
This species is herbivorous. They eat fruits of the Manilkara genus and the Pandanus genus, including screw-pine and thatch screwpine.When eating a piece of fruit, they will suck out the juices and discard the rest instead of consuming it entirely.They consume ornamental plants including Agave americana.They are also known to eat ferns, based on the presence of Asplenium spores in their guano.Other components of their diet include soursop fruit, sugar-apples, banana fruits, leaves, and flowers, traveller's palm flowers, giant white bird of paradise flowers, pitahaya fruit, Indian-almond fruit, Java apple fruit and flowers, guava fruit, weeping paperbark flowers, Albany bottlebrush flowers, litchi fruit, key lime fruits, Meyer lemons, pomelos, grapefruit, amanatsu fruit, sweet oranges, tangerines, mangos, figs, and Chinese mulberries.
Copulation is frequent in winter colonies, with as many as 27 instances observed per day in colonies with large proportions of female bats. During mating, the bats screech loudly, and males will lick the female's vulva. This species probably has the ability to breed year-round. Gestation is estimated at 5–7 months, after which the female gives birth to one pup. Pups are most frequently seen in August, though they have been observed in February, March, April, and December as well.
In 1994 and 1996, the Bonin flying fox was classified as vulnerable by the IUCN. In 2000, the classification was revised to critically endangered. In 2017, they were downlisted to endangered. They are considered endangered because their extent of occurrence is less than 100 km2 (39 sq mi), their habitat is severely fragmented, and the population is estimated at fewer than 250 mature individuals.In 1969, this species was listed as a Natural Monument of Japan. This law made it illegal to capture or hunt them.The population of bats Chichijima Island was estimated at 150 individuals in 1997, but by 2002, it was estimated at only 65-80 individuals.Possible reasons for their decline include entanglement in agricultural nets and depredation by feral cats.It is speculated that they are threatened by competition with invasive species, including rats, white-eyes, and honey bees.
