Sunday, May 17, 2009

Vanishing Species - The Indian Flying Fox

An article by Mohan Pai
The Indian Flying Fox
Pteropus giganteus
The world’s only true, largest flying mammal with a sustained flight who feeds only on ripe fruits.
A bat is the only mammal with wings, the only mammal which can really fly. There are mammals like the flying squirrels, and flying lemurs, which glide through the air supported by parachute-like extensions of skins on their bodies and allow it only a prolonged glide. Whereas with bats there is true and sustained flight effected by an upward and downward beat of their wings. Fruit bats are larger than the carnivore bats and the Flying Fox is the largest. The wing span of the Flying Fox is about 4 ft.
The Flight clearly distinguishes bats from all the other mammals. Not just jumping, or gliding, but actually being able to fly - like the birds. The entire bone structure of bats is modified for flight, and as we should expect, this is most noticeable in the arms. As the name "Chiroptera" ("hand wing”) translates, the wings are formed by a stretched membrane across elongated finger bones to the sides of the body and all the way down enclosing the legs and tail. The wing membrane is naked, although in some species the body fur may grow somewhat out onto the wing. When the wing is not extended the membrane folds up along countless creases more efficiently than an umbrella.
The world's only true flying mammals, bats are all gathered into one order, Chiroptera. They probably developed from arboreal insectivores, possibly tree-dwelling animals, 70,000,000 years ago, and possibly as far back as 100,000,000 years. Their species number almost 1000, second only to the Rodents. Bats are found in every part of the world except the polar regions and far out across the ocean. The order is clearly divisible into two very distinct suborders: the Megachiroptera, consisting of 173 species of flying foxes and other large fruit bats; and the Microchiroptera, which contains all the other smaller, generally insectivorous, bats. So diverse are the small bats that they have been sorted into 16 separate families, while the fruit bats are all contained in a single family. The large bats inhabit the tropics and subtropics of Africa and Australia and Asia, while the small bats are found worldwide. Rather than displaying quick maneuvers, flying foxes have a powerful and steady type of flight. They use their acute vision, even when flying at night. The small bats have reasonably good eyesight but do not depend upon it in flight. Instead they have developed a remarkable sense of hearing and guide themselves by echolocation, or sonar. This type of bat constantly emits high-frequency clicking sounds, up to 200 per second, and outside the highest range of human hearing. When the sound waves strike objects in their path an echo is returned to the bat. It can then judge distances between itself and an object, such as a stone wall or a tiny insect, and so it literally hears its way around. Since bats in flight perceive insects in this manner, this accounts for their sudden darting twists, turns, and dives while in pursuit. If bats are indeed evolved from insectivores, then echolocation as a means of finding flying insects in the dark probably developed very early on. Bats eat all types of nocturnal insects, but beetles and moths probably top the list. Yet some species of small bats have forsaken a diet of insects, and feed on ripe fruit, while others feed on nectar and pollen.

The Indian Flying-fox (Pteropus giganteus) is a species of bat in the Pteropodidae family. It is found in Bangladesh, China, India, Maldives, Nepal, Pakistan, and Sri Lanka. The Greater Indian Fruit Bat lives in mainly forests. It is a very large bat with a wing span of around 80 centimeters. It is nocturnal and feeds mainly on ripe fruits such as mangoes and bananas and nectar. This bat is gregarious and lives in colonies which can number a few hundred. Their offspring has no specific name besides 'young'. They reproduce sexually and give live birth. They have one to two young.
Range and Habitat: Pakistan, India, Myanmar and Sri Lanka. They roost in trees (especially banyans, figs and tamarinds) or clumps of bamboo. Habits and Adaptations: Flying foxes live in colonies of several hundred to several thousand individuals. Each bat has a specific resting place. There is a rank structure among males based on size and strength. No male-female bonds are formed. The bats fly to their feeding sites shortly after sundown. They spend most of the night feeding, returning to the roost at about 4 a.m. During the day sleep is interrupted by short periods of watchfulness. The colony is never completely still. Flying foxes do not echo-locate, like insectivorous bats. They fly entirely by sight. During hot weather these bats fan themselves with their wings and spread saliva over their bodies to help keep cool. Diet: Almost exclusively juice from fruits, including mangos, bananas, papayas, figs, sapotes and guaras. The pulp and seeds are usually spit out. Blossoms and nectar are also eaten.
Breeding and Maturation: Courtship consists of the male shrieking shrilly into the female's ear until she allows copulation. Flying foxes are seasonal breeders, with young being born when food is most plentiful. The time of birth varies from January, in parts of India, to June in Sri Lanka. The single young is born after a 140-150 day gestation. The young weigh about 75 g. at birth. They first begin to hang by themselves at about three weeks. They begin to fly when around 11 weeks old, and are weaned by five months. Sexual maturity occurs at about 18 months.
Miscellaneous: Bats, due to their nocturnal nature, are high in spook hierarchy of folk tales and horror films. According to Indian folk medicine, a wing bone from a flying fox tied to the ankle with a tail hair from a black cow results in painless childbirth. The captive longevity record is 31 years.
Painting of the Flying Fox by Bhawani Das of Patna, circa 1778-82 on sale at Christies’s last year. Estimated price $ 3,32,114.
References: “The Book of Indian Animals” by S. H. Prater, Wikipedia, Minnesota Zoo - Animals, America Zoo
MY BLOG LIBRARY
For some of my articles visit:
For some key chapters from my book "The Western Ghats", please log on to:
For detailed blog (6 Chapters) on Mahadayi/Mandovi River Valley, please log on to:
For the book 'The Elderly' please log on to:
You can also access my blogs on Sulekha & Wordpress:
For my book "The Flight of Gods - Hindu Temples & Shrines of Goa" please log on to:

1 comment:

Unknown said...

Ideal habitats and colonies of the indian flying foxes are often destroyed. We had a lot of colonies on several huge trees across kerala, but now they are rare to see. I have some pictures of the indian flying fox in my website. They sometimes visit our backyard at Kerala.