Pteropus giganteusIndian flying fox

Geographic Range

Pteropus giganteus occurs in tropical regions of South Central Asia, from Pakistan to China, and as far south as the Maldive Islands. (Nowak, 1999)

Habitat

These animals can be found in forests and swamps. Large groups of individuals roost in trees such as banyan, fig, and tamarind. Roosting trees are usually in the vicinity of a body of water. ("Indian Flying Fox (Pteropus giganteus)", 2004; Marimuthu, 1998; Nowak, 1999)

Physical Description

The physical appearance of this species is similar to that of megachiropterans in general, with large eyes, simple ears, and no facial ornamentation. Dark brown, gray, or black body color with a contrasting yellowish mantle is typical of the genus Pteropus. Body mass ranges from 600 to 1600 g and males are generally larger than females. Wingspan may range from 1.2 to 1.5 m and body length averages 23 cm. Members of the genus Pteropus maintain body temperatures between 33 and 37 C, but must do this through constant activity. (Marimuthu, 1998; Nowak, 1999; Thatcher, 2004; "Greater Indian Fruit Bat (Indian Flying Fox)", 2002)

  • Sexual Dimorphism
  • male larger
  • Range mass
    600 to 1600 g
    21.15 to 56.39 oz
  • Average length
    23 cm
    9.06 in
  • Range wingspan
    1.2 to 1.5 m
    3.94 to 4.92 ft
  • Average basal metabolic rate
    1.622 W
    AnAge

Reproduction

This species is polygynandrous, with no pair bonds occurring between males and females. Females are defended from intruding males by males that live in their roosting tree. (Altringham, 1996)

Pteropus giganteus breeds yearly, with mating occurring from July to October, and births occurring from February to May. To initiate copulation, a male will fan his wings toward a female, and persistently follow her until he is able to grip the scruff of her neck with his teeth and hold her with his thumbs. Copulation occurs for a duration of 30 to 40 seconds. The female usually vocalizes and physically resists the advances of the male during the encounter. After copulation, the male again follows the female while vocalizing loudly. Gestation period is typically 140 to 150 days, after which 1 to 2 young are born. Like other members of the genus Pteropus, the young are carried by the mother for the first few weeks of life. Sexual maturity for this species occurs at about 1.5 years of age. (Koilraj, et al., 2001; "Greater Indian Fruit Bat (Indian Flying Fox)", 2002; Koilraj, et al., 2001; "Greater Indian Fruit Bat (Indian Flying Fox)", 2002; Koilraj, et al., 2001; Nowak, 1999; Thatcher, 2004; "Greater Indian Fruit Bat (Indian Flying Fox)", 2002)

  • Breeding interval
    Mating occurs once yearly.
  • Breeding season
    Mating season is between the months of July and October.
  • Range number of offspring
    1 to 2
  • Average number of offspring
    1
  • Average number of offspring
    1
    AnAge
  • Range gestation period
    140 to 150 days
  • Average weaning age
    5 months
  • Average age at sexual or reproductive maturity (female)
    1.5 years
  • Average age at sexual or reproductive maturity (female)
    Sex: female
    365 days
    AnAge
  • Average age at sexual or reproductive maturity (male)
    1.5 years
  • Average age at sexual or reproductive maturity (male)
    Sex: male
    365 days
    AnAge

After birth, young are carried by the mother for the first three weeks of life. They begin to hang by themselves after this time period, but are still carried to feeding sites by the mother. Young learn to fly at about 11 weeks of age and are weaned at 5 months. Males do not participate in parental care. (Nowak, 1999; "Greater Indian Fruit Bat (Indian Flying Fox)", 2002)

  • Parental Investment
  • altricial
  • pre-fertilization
    • provisioning
    • protecting
      • female
  • pre-hatching/birth
    • provisioning
      • female
    • protecting
      • female
  • pre-weaning/fledging
    • provisioning
      • female
    • protecting
      • female
  • pre-independence
    • protecting
      • female
  • inherits maternal/paternal territory

Lifespan/Longevity

The longest lifespan of an individual of this species in captivity was recorded at 31 years, 5 months. Little information is available regarding life expectancy in the wild. (Nowak, 1999)

Behavior

Pteropus giganteus is a social species, with large groups of several hundred individuals living in the same tree. Males may maintain a vertical dominance hierarchy of resting spots in the tree, and may also defend the roost and associated females from intruders. During the day, these animals sleep, hanging upside down by their feet with their wings wrapped around themselves. They also fan themselves to aid in thermoregulation, move around in the roosting tree, and communicate with each other. As they are nocturnal, they leave the tree at sunset to feed, returning after several hours of finding food, feeding, digesting, and resting. (Marimuthu, 1998; Nowak, 1999)

Home Range

The roosting tree is the area in which Indian flying foxes spend the majority of the day. This species, as well as other large species of Pteropus, is reported to travel up to 15 km to find food. (Thatcher, 2004)

Communication and Perception

Communication among individuals of this species is vocal. They chatter and squawk when threatened. Typical of megachiropterans, P. giganteus does not echolocate, and relies on sight rather than hearing for navigation. Because of their use of vision, there is probably communication involving body postures and positioning. Tactile communication is important during mating, as well as between mothers and their offspring. (Marimuthu, 1998; Thatcher, 2004)

Food Habits

Pteropus giganteus is frugivorous, as are other species of the Suborder Megachiroptera, otherwise known as the Old World fruit bats. This species has been reported to eat many different species of fruit, including guava, mango, and fig. An individual of the genus Pteropus squeezes out fruit juices from the pulp against the roof of its mouth, and then discards the dry material. Some Pteropus species also supplement their dietary protein by eating insects. Others, including P. giganteus, eat the blossoms and nectar of fruiting plants. (Marimuthu, 1998; Thatcher, 2004; "Greater Indian Fruit Bat (Indian Flying Fox)", 2002)

  • Plant Foods
  • fruit
  • nectar
  • flowers

Predation

Major predators of this species are humans, snakes and raptors. ("Indian Flying Fox (Pteropus giganteus)", 2004)

Ecosystem Roles

This species, along with other species of the genus Pteropus, plays a role in seed dispersal. It is also eaten by snakes and raptors. (Marimuthu, 1998)

  • Ecosystem Impact
  • disperses seeds
Species Used as Host
  • little information available
Mutualist Species
  • little information available
Commensal/Parasitic Species
  • little information available

Economic Importance for Humans: Positive

Humans in some regions benefit from Indian flying foxes by hunting them for food and medicinal purposes. (Marimuthu, 1998)

Economic Importance for Humans: Negative

Indian flying foxes cause extensive damage to fruit orchards, and are therefore considered pests in many regions. They may also be responsible for spreading disease, particularly the Nipah virus, which causes illness and death in humans. ("Nipah Encephalitis Outbreak Over Wide Area of Western Bangladesh", 2002; Kunz and Racey, 1998; Marimuthu, 1998; Thatcher, 2004)

  • Negative Impacts
  • injures humans
    • carries human disease
  • crop pest

Conservation Status

This species is listed in CITES Appendix II, meaning it is not currently threatened, but could become so if protective measures are not taken.

Other Comments

Although not considered an at risk species, P. giganteus is subject to lethal, officially sanctioned control measures in many areas, including the Maldive Islands, Pakistan, and India, because of their negative effects on fruit orchards. Despite this negative impact, this species is protected and considered sacred by people in certain regions of India. (Kunz and Racey, 1998; Marimuthu, 1998; Nowak, 1999)

Contributors

Erin Silbernagel (author), University of Alaska Fairbanks, Link Olson (editor, instructor), University of Alaska Fairbanks.

Nancy Shefferly (editor), Animal Diversity Web.

Glossary

acoustic

uses sound to communicate

altricial

young are born in a relatively underdeveloped state; they are unable to feed or care for themselves or locomote independently for a period of time after birth/hatching. In birds, naked and helpless after hatching.

arboreal

Referring to an animal that lives in trees; tree-climbing.

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

chemical

uses smells or other chemicals to communicate

colonial

used loosely to describe any group of organisms living together or in close proximity to each other - for example nesting shorebirds that live in large colonies. More specifically refers to a group of organisms in which members act as specialized subunits (a continuous, modular society) - as in clonal organisms.

dominance hierarchies

ranking system or pecking order among members of a long-term social group, where dominance status affects access to resources or mates

drug

a substance used for the diagnosis, cure, mitigation, treatment, or prevention of disease

endothermic

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

fertilization

union of egg and spermatozoan

food

A substance that provides both nutrients and energy to a living thing.

forest

forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.

frugivore

an animal that mainly eats fruit

herbivore

An animal that eats mainly plants or parts of plants.

heterothermic

having a body temperature that fluctuates with that of the immediate environment; having no mechanism or a poorly developed mechanism for regulating internal body temperature.

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

motile

having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.

nocturnal

active during the night

oriental

found in the oriental region of the world. In other words, India and southeast Asia.

World Map

polygynandrous

the kind of polygamy in which a female pairs with several males, each of which also pairs with several different females.

rainforest

rainforests, both temperate and tropical, are dominated by trees often forming a closed canopy with little light reaching the ground. Epiphytes and climbing plants are also abundant. Precipitation is typically not limiting, but may be somewhat seasonal.

seasonal breeding

breeding is confined to a particular season

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

social

associates with others of its species; forms social groups.

swamp

a wetland area that may be permanently or intermittently covered in water, often dominated by woody vegetation.

tactile

uses touch to communicate

territorial

defends an area within the home range, occupied by a single animals or group of animals of the same species and held through overt defense, display, or advertisement

tropical

the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.

visual

uses sight to communicate

viviparous

reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.

References

The Minnesota Zoo. 2002. "Greater Indian Fruit Bat (Indian Flying Fox)" (On-line). Minnesota Zoo. Accessed February 12, 2004 at http://www.mnzoo.com/animals/tropics_trail/fbat_1.asp.

2004. "Indian Flying Fox (Pteropus giganteus)" (On-line). Utah's Hogle Zoo. Accessed February 12, 2004 at http://www.hoglezoo.org/animals/view.php?id=82.

ICDDR,B: Centre for Health and Population Research. 2002. "Nipah Encephalitis Outbreak Over Wide Area of Western Bangladesh" (On-line). ICDDR,B: Centre for Health and Population Research. Accessed February 12, 2004 at http://202.136.7.26/pub/publication.jsp?classificationID=56&pubID=5144.

Altringham, J. 1996. Bats: Biology and Behaviour. Oxford: Oxford University Press.

Koilraj, B., G. Agoramoorthy, G. Marimuthu. 2001. Copulatory Behaviour of Indian flying fox Pteropus giganteus. Current Science, 80/1: 15-16. Accessed February 12, 2004 at http://www.ias.ac.in/currsci/jan102001/15.pdf.

Kunz, T., P. Racey. 1998. Bat Biology and Conservation. Washington: Smithsonian Institution Press.

Marimuthu, G. 1998. The Sacred Flying Fox of India. Bats, 9/2: 10-11. Accessed October 19, 2004 at http://www.batcon.org/batsmag/v6n2-3.html.

Nowak, R. 1999. Walker's Mammals of the world. Baltimore and London: The Johns Hopkins University Press.

Thatcher, O. 2004. "Fruit and Nectar Bat Biology" (On-line). Lubee Bat Conservacy. Accessed October 19, 2004 at http://www.lubee.org/about-biology.aspx.