Gyps bengalensis

Geographic Range

Gyps bengalensis is very common on the Indian subcontinent. It regularly occurs in Pakistan, India, Bangladesh, Nepal, Bhutan, Myanmar (Burma), Thailand, Laos, Cambodia, and southern Vietnam. It formerly occurred in southern China and Malaysia but is now extinct in that region. It has also been found in southern and central Afghanistan, mostly in the southern area but has also been sighted in the central part of Afghanistan. In Pakistan, G. bengalensis is found mostly in the Indus valley and along the Himalayas to Assam valley and the southern parts of the Assam hills.

• Biogeographic Regions
• palearctic palearctic
  • native native

Habitat

White-rumped vultures are often found in cities, towns and villages, near human habitation. They occur in temperate areas, mostly in plains and occasionally in hilly regions. Gyps bengalensis is generally found in open areas and fields enclosing scattered trees. White-rumped vultures feed mostly on the ground, but roost and nest in trees and cliffs, and spend much of their time soaring on wind currents searching for carrion. Nests are typically 2 to 18 meters above the ground.

• Habitat Regions
• temperate temperate
• terrestrial terrestrial

• Terrestrial Biomes
• savanna or grassland savanna or grassland
• chaparral chaparral

• Other Habitat Features
• urban urban
• suburban suburban
• agricultural agricultural

Physical Description

White-rumped vultures are medium-sized, dark vultures. Adults are 75 to 85 cm tall, their wing span is 180 to 210 cm, and their weight ranges from 3.5 to 7.5 kg. The sexes are approximately equal in size. Adults are darker than juveniles, with blackish plumage, a white neck-ruff, and a white patch of feathers on the lower back and upper tail, from which their common name is derived. There is a pale grey patch on the upper surface of the wings, visible when the wings are folded. The undersides of the wings are a dark slate to brownish color. During flight, the white underwing coverts are highly visible. Usually the eyes are a yellowish brown color and the legs are blackish. The bill is short, deep, and stout.

Immature G. bengalensis are dark brown and the lower back and rump area are brown rather than white. The underwing coverts are dark brown. Eyes are dark brown and the legs are blackish but lighter than the adult. Generally, adults tend towards black coloration, while younger individuals are browner. All G. bengalensis can be distinguished by the white bar located on the underside of the wing.

• Other Physical Features
• endothermic endothermic
• homoiothermic
• bilateral symmetry bilateral symmetry

• Sexual Dimorphism
• sexes alike

Reproduction

The breeding season of G. bengalensis is from October to March. Both sexes display by flying in circles very slowly near the breeding area with the wing tips close together. Mating occurs at the nest or on a branch very close to the nest. Mating is associated with loud calling. Mating is monogamous, at least within seasons. The first stage of breeding in white-rumped vultures is nest-building. Breeding colonies are built on large trees and rock cliffs. Cliffs are favored over trees because they provide security from terrestrial predators and require fewer twigs to build the nest. Nesting trees must have well-spaced branches so that the bird has room for movement. Usually, the male gathers the twigs and the female arranges them to build the nest.

• Mating System
• monogamous monogamous

Only one egg is laid in each clutch. There have been reports of two eggs but it is assumed that two different females residing in the same nest laid one egg each. The egg is white with very light markings of red-brown and overlying grey or lavender markings. Unmarked eggs are uncommon, and boldly marked eggs occasionally occur. After some time, the egg becomes discolored due to parental droppings. The shell is thick and strong, for protection during incubation. Some eggs are long ovals and others may be spherical. Incubation usually lasts 45 to 52 days and both sexes participate in this process. The newly hatched chick is very small, about 15cm. Young remain in the nest for 2-3 months, with both parents regurgitating food for the nestling during that time. Age at independence and sexual maturity are not known.

• Key Reproductive Features
• iteroparous iteroparous
• seasonal breeding seasonal breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual sexual
• oviparous oviparous

The young remain in the nest for two to three months after hatching. For feeding, the adults bring a carcass to the newborn and feed it a few times a day. After about 15 days, parental care is minimal. The whole breeding cycle lasts six months.

• Parental Investment
• altricial altricial
• pre-fertilization
  • provisioning
  • protecting
    • female
• pre-hatching/birth
  • provisioning
    • female
  • protecting
    • male
    • female
• pre-weaning/fledging
  • provisioning
    • male
    • female
  • protecting
    • male
    • female

Lifespan/Longevity

There is little available information on the lifespan of Gyps bengalensis .

Behavior

White-rumped vultures are social animals, living in flocks year-round, often with other vulture species. They breed in loose colonies. Typically, G. bengalensis is found in lines of trees close to rivers, in a jungle, in big trees within towns of villages, or near slaughter houses (in close proximity to food). Up to 15 large nests may be observed in a single roost tree. At night, white-rumped vultures roost in trees. Both night roosts and breeding roosts are often used for long periods of time. They rest for about two hours before dark. Typical flight speeds are between 50 and 55 miles per hour but can reach speeds up to 90 miles per hour. They can soar up to 9,000 feet but do not nest higher than 3,500 feet. White-rumped vultures have adapted well to living near humans. Occasionally, they can come into conflict with the human population in close proximity to them.

• Key Behaviors
• arboreal arboreal
• flies
• diurnal diurnal
• motile motile
• sedentary sedentary
• social social

Communication and Perception

White-rumped vultures communicate with an assortment of grunts, hisses, and squeals. During mating, the female usually makes a loud, unpleasant call. Birds that are being incubated may croak or hiss. It is also possible that postures and movements are used to communicate among individuals. These vultures have a keen sense of vision, for locating carcasses, and can hear well.

• Communication Channels
• visual visual
• acoustic acoustic

• Perception Channels
• visual visual
• tactile tactile
• acoustic acoustic
• chemical chemical

Food Habits

White-rumped vultures feed almost exclusively on the remains of dead animals, regardless of whether it is fresh or putrid. Many populations of G. bengalensis forage through dumpsters for food. Those that live by slaughter houses obtain food from dumpsters as well. White-rumped vultures also feed on fish from lakes that have dried out. In India these vultures eat mainly cattle and human remains. When these vultures feed, they tear open the flesh with their beaks and start feeding from the supple flesh near the tail. They fight over the food between themselves, kicking and flapping their wings to drive other vultures away. White-rumped vultures will gorge themselves with carrion if given the chance, leaving them unable to fly because of the amount of food they have eaten.

This species doesn’t usually capture prey as a means for survival. Generally, it feeds on carcasses. However, occasionally vultures will kill animals for food. One instance of a vulture attacking a calf has been noted. A group of vultures rushing a flock of village ducks has also been noted.

• Primary Diet
• carnivore carnivore
  • scavenger scavenger

• Animal Foods
• birds
• fish
• carrion carrion

Predation

In Bangladesh, white-rumped vultures are known to build nests at lower heights than normal. Because of this, eggs may be taken by lizards, pythons, and other carnivores. Also, humans may be a threat to Gyps bengalensis because of the usage of vultures as a source of medicines. A very small number of this species has been captured for pets and for display in circuses. Normally they are not hunted for food.

Ecosystem Roles

Gyps bengalensis is important as a scavenger in the ecosystems in which they live.

Economic Importance for Humans: Positive

White-rumped vultures are important in helping prevent the spread of diseases by ridding areas of carcasses. Declines in vulture numbers in India and Pakistan are resulting in an increase of carcasses remaining to feral dog populations, leading to an increase in the number of feral dogs, which transmit rabies to human populations.

Economic Importance for Humans: Negative

The danger of collision between birds and airplanes is a grave fear of pilots everywhere but especially in India, where vultures contribute to 25% of bird-plane strikes. Of this percentage, Gyps bengalensis causes the most problems because of its commonness, weight, its habit of flocking, and its ability to fly to high altitudes.

Conservation Status

There are many threats to Gyps bengalensis . Disease, pesticides, environmental contamination, poisoning, reduced food availability, calcium deficiency, reduced nesting habitat, nest predators, hunting, and aircraft strikes are the most common. DDT and HCH pesticides have been banned in India but are still extensively used. High levels of these two pesticides have been found in tissue samples in carcasses. Breeding declines of this species seem to be congruent with pesticide usage, however more recent studies have established a strong link between catastrophic Asian vulture declines (including this species, which is now listed as Critically Endangered) and consumption of carcasses of animals treated with the veterinary drug diclofenac. Other vulture poisoning incidents may result from the intentional poisoning of carcasses, usually to rid a town of predatory mammals. Populations of white-rumped vultures have declined by as much as 95% in Pakistan and India. Populations in southeastern Asia disappeared in the early 20th century, disappearing altogether from Malaysia and southern China.

Other Comments

Gyps bengalensis is believed by some authors to be very closely related to or even conspecific with Gyps africanus found in Africa. Pseudogyps bengalensis is another scientific name by which Gyps bengalensis was previously known. Another common name is white-backed vulture.

Additional Links

Encyclopedia of Life

Contributors

Pamela Rasmussen (editor, instructor), Michigan State University, Tanya Dewey (editor), Animal Diversity Web.

Arya Khatiwoda (author).

References

Amadon, D., L. Brown. 1968. Eagles, Hawks, and Falcons of the World . Feltham, Middlesex: Country Life Books, Hamlyn.

Dharmakumarsinhji, . 1955.

Birds of Saurashtra, India

Grubh, R. 1973. Calcium intake in vultures of the genus Gyps. Journal of the Bombay Natural History Society , 70: 199-200.

Grubh, . 1974. Journal of the Bombay Natural History Society.

Field identification of some Indian vultures

Prakash, V. 1989. Indian scavenger vulture (Neophron percnopterus ginginianus) feeding on a dead White-backed Vulture (Gyps bengalensis). Journal of the Bombay Natural History Society , 85: 614-615.

Prakash, V. 1999. Vulture red alert. Hornbill , July-September: 28-29.

Rasmussen, P., J. Anderton. 2005. Birds of South Asia: The Ripley Guide . Barcelona: Lynx Edicions.

Satheesan, S. 1989. Close encounters of the bird kind. Hornbill , January: 22-25.

Wells, D. 1999. The Birds of the Thai-Malay Peninsula . San Diego: Academic Press.

1990. Handbook of the Birds of the World. Volume 2 . Cambridge, UK: BirdLife International.

2001. Threatened birds of Asia: the BirdLife International Red Data Book . Cambridge, UK: BirdLife International.

2004. "Arkive: Images of Life on Earth." (On-line). Asian white-backed vulture.. Accessed April 14, 2005 at http://www.arkive.org/species/GES/birds/Gyps_bengalensis/more_info.html .

2004. "BirdLife: International" (On-line). BirdLife Species Factsheet. Accessed April 13, 2005 at http://www.birdlife.net/datazone/search/species_search.html?action=SpcHTMDetails.asp&sid=3374&m=0 .