Indian Flying Fox

The **Indian flying fox** (*Pteropus medius*, formerly *Pteropus giganteus*), also known as the greater Indian fruit bat, is a species of flying fox native to the Indian subcontinent. It is one of the largest bats in the world. It is of interest as a disease vector, meaning it is capable of transmitting several viruses and diseases to humans. It is nocturnal and feeds mainly on ripe fruits, such as mangoes and bananas, and nectar. This species is often regarded as vermin due to its destructive tendencies towards fruit farms, but the benefits of its pollination and seed propagation often outweigh the impacts of its fruit consumption.

## Description

The Indian flying fox is India's largest bat, and one of the largest bats in the world, weighing up to 1.6 kg (3.5 lb). Its body mass ranges from 0.6–1.6 kg (1.3–3.5 lb), and males are generally larger than females. The wingspan ranges from 1.2–1.5 m (3 ft 11 in–4 ft 11 in) and body length averages 15.5–22.0 cm (6.1–8.7 in). The wings rise from the side of the dorsum and from the back of the second toe, and its thumb has a powerful claw. It has claws on only its first two digits of its wings, with the thumb possessing the more powerful claw, and all five digits of its leg. It lacks a tail.

The Indian flying fox ranges in color, with a black back that is lightly streaked with grey, a pale, yellow-brown mantle, a brown head, and dark, brownish underparts. It has large eyes, simple ears, and no facial ornamentation—a typical appearance for a species of the genus *Pteropus*. The skull is oval-shaped and the greatest length of the skull is 71–75.6 mm (2.80–2.98 in). The orbital rim of the skull is incomplete. The ears lack a tragus or antitragus and are ringed, and the ears range in length from 35–40 mm (1.4–1.6 in) in length.

The dental formula is 3.1.4.22.1.4.3. The first upper premolar is absent, the canine is pronounced, and the molars have a longitudinal furrow.

As of 1999, it is the longest-lived member of its genus; one individual lived for 31 years and 5 months in captivity.

## Distribution and habitat

The Indian flying fox is found across the Indian Subcontinent, including in Bangladesh, Bhutan, India, Tibet, Maldives, Myanmar, Nepal, Pakistan and Sri Lanka.

It roosts in large, established colonies on open tree branches, especially in urban areas or in temples. It prefers to roost on tall trees with small diameters, especially canopy trees, and prefers to be in close proximity to bodies of water, human residences, and agricultural land. This habitat selection is highly dependent on food availability. For example, many residences within the bat's distribution have outdoor gardens that support its generalist frugivorous feeding habits. This tendency to support a generalist frugivorous diet through habitat selection also leads it to commonly roost in highly fragmented forests, where the variety of plant species allows it to better utilize its feeding habits.

Its populations are constantly threatened through habitat destruction caused by urbanization or widening of roads. Tree roosts are often felled and colonies dispersed. Smaller colonies tend to remain in place longer than larger colonies, as those larger colonies have their roosts felled more quickly.

## Ecology

### Diet

The Indian flying fox is frugivorous or nectarivorous, (i.e., they eat fruits or drink nectar from flowers.) At dusk, it forages for ripe fruit. It is a primarily generalist feeder, and eats any available fruits. Seeds from ingested fruits are scarified in its digestive tract and dispersed through its waste. It is relied on for seed propagation by 300 plant species of nearly 200 genera, of which approximately 500 economically valuable products are produced in India. Nearly 70% of the seeds in Indian flying fox guano are of the banyan tree, a keystone species in Indian ecosystems.

Although initially thought to be strictly frugivorous, it has been observed deliberately eating insects and leaves. The Indian flying fox also eats flowers, seed pods, bark, cones, and twigs. Their diet changes seasonally, with a greater reliance on mango fruits for moisture in the autumn and spring. A species of ebony tree (pale moon ebony tree) provides dietary fiber year-round. Yellow box eucalyptus and Chinese pistache provide necessary carbohydrates, fats, iron, and phosphorus in the winter.

### Behavior

The Indian flying fox roosts communally in the treetops of large trees in camps often with thousands of bats. Roosts tend to be used for upwards of ten years, and are usually inhabited year-round rather than seasonally. Within the roost the bats quarrel and chatter often, and during sunny hours of the day bats fan their wings and call, and during cloudy periods bats are silent and wrap their wings around their body. Occasionally a few bats fly around the roost during the day, but most activity is restricted to night, when they leave the roost one by one 20–30 minutes after the sunset. Bats at the top of the roost tend to circle the roost and leave before the rest of the colony emerges. The time of bat emergence was significantly influenced by the day length, sunset and the ambient temperature delayed the time of emergence. The bats fly with the appearance of a large swarm but forage individually, and give off contact calls infrequently. Individuals travel upwards of 93 mi (150 km) in search of food, finding it by sight. It can quickly travel up and down tree branches to forage for fruit with a swift hand-over-hand motion.

A diseased Indian Flying fox hanging on Telephone Wires in Sri Lanka