White Rumped vulture

The white-rumped vulture (Gyps bengalensis) is an Old World vulture native to South and Southeast Asia and is one of the most striking examples of a rapid, human-driven population collapse in modern conservation history. Once among the most abundant large birds of prey on Earth, the species has undergone catastrophic declines since the late twentieth century. It has been listed as Critically Endangered on the IUCN Red List since 2000, primarily due to widespread mortality caused by veterinary drug contamination. The dramatic reduction of this species has had profound ecological, cultural and public health implications across the Indian subcontinent.

Taxonomy and evolutionary relationships

The white-rumped vulture was first formally described in 1788 by the German naturalist Johann Friedrich Gmelin, who placed it in the genus Vultur under the name Vultur bengalensis. The description was based on earlier accounts of a bird known as the “Bengal vulture”, observed in captivity in London and believed to have originated from Bengal.
In 1809, the species was reassigned to the genus Gyps, introduced by the French zoologist Marie Jules César Savigny. The genus name derives from the Ancient Greek gups, meaning vulture. The white-rumped vulture is now recognised as one of eight species within this genus and is considered monotypic, with no recognised subspecies.
Phylogenetic studies indicate that Gyps bengalensis is closely related to the European griffon vulture (Gyps fulvus). Earlier assumptions suggested a closer relationship with the African white-backed vulture, leading to its former common name, the “Oriental white-backed vulture”. Molecular evidence has since clarified its position as a basal species within the Gyps clade, with other Asian, African and European species diverging later.

Physical description

The white-rumped vulture is a medium-sized vulture, though still a very large bird by general avian standards. It is the smallest member of the genus Gyps. Adults typically weigh between 3.5 and 7.5 kg, measure approximately 75–85 cm in length, and possess a wingspan of about 200–220 cm.
The species exhibits classic vulture morphology, including very broad wings adapted for soaring, a short tail, and an unfeathered head and neck. A white neck ruff is present, separating the bare head from the darker body. Adults are characterised by a pale or whitish rump, back and underwing coverts, which contrast strongly with the otherwise dark brown to black plumage. The secondaries appear silvery grey, and the head is often tinged pink. The bill is silvery with darker ceres, and the nostrils are narrow and slit-like.
Juveniles are uniformly dark and lack the distinctive pale rump. They require four to five years to attain full adult plumage. In flight, adults show a dark leading edge to the wing and a conspicuous white wing-lining on the underside, while the undertail coverts remain black.

Distribution and habitat

Historically, the white-rumped vulture was widespread across the Indian subcontinent and parts of Southeast Asia. Its range included India, Pakistan, Nepal, Bangladesh, Sri Lanka and extending eastwards into Myanmar and neighbouring regions.
The species favours open landscapes such as plains, river valleys, agricultural areas and lightly wooded regions. It has shown a strong tolerance for human-modified environments and was commonly found nesting near towns and villages. Tall trees, particularly fig (Ficus), Terminalia and neem trees, were frequently used for nesting, often close to human habitation.
Today, the species’ distribution has become highly fragmented, with only small, scattered populations remaining, largely restricted to protected areas and regions with targeted conservation efforts.

Behaviour and feeding ecology

White-rumped vultures are obligate scavengers, feeding almost exclusively on carrion. They rely on soaring flight, using rising air thermals to cover large distances in search of carcasses. Once a carcass is located, they descend rapidly and feed in large groups.
The species is highly social, often flying, roosting and feeding in flocks. Historically, enormous congregations were recorded, particularly around large cities and river systems. At carcasses, white-rumped vultures are often subordinate to larger or more aggressive species such as the red-headed vulture (Sarcogyps calvus).
Their diet consists primarily of soft tissues, although they are capable of swallowing small bones and skull fragments from smaller animals. Feeding can be extremely rapid, with groups historically able to reduce a large livestock carcass to bones within minutes.
Roosting trees are frequently coated in white excreta, the acidity of which can damage or kill vegetation, making the birds unpopular in orchards and plantations. Bathing and drinking occur regularly when water is available.

Breeding biology

The white-rumped vulture is primarily a tree-nesting species. Breeding pairs often nest in loose colonies, sometimes with hundreds of nests in close proximity. Preferred nesting trees include banyan (Ficus benghalensis), Terminalia arjuna and neem.
The main breeding season extends from November to March, with egg-laying typically occurring in January. Each pair usually lays a single egg, which is white with a faint bluish-green tinge. Incubation lasts approximately 30–35 days.
Both parents participate in nest building, incubation and chick rearing. The chick hatches covered in grey down and remains in the nest for around three months, during which it is fed regurgitated meat. Breeding success is naturally low, as only one offspring is produced per breeding attempt, making populations highly sensitive to adult mortality.

Population history and decline

In the 1980s, the global population of the white-rumped vulture was estimated at several million individuals, and it was widely regarded as the most abundant large bird of prey in the world. It was particularly common in the Gangetic plains, where it nested in large numbers even within major cities.
By the early 1990s, alarming declines were already evident in parts of India. Since then, the species has suffered a population collapse of over 99% across much of its range. As of 2021, the global population was estimated to consist of fewer than 6,000 mature individuals.
Annual rates of decline during the peak period of collapse were exceptionally high, exceeding 40% in some regions. Such rates are among the most severe recorded for any bird species.

Causes of decline

The primary cause of the white-rumped vulture’s decline has been poisoning by the veterinary drug diclofenac, a non-steroidal anti-inflammatory drug widely used in livestock. Residues of diclofenac persist in the carcasses of treated cattle. When vultures feed on these carcasses, even minute quantities of the drug cause acute kidney failure, leading to death within days.
Diclofenac toxicity has been shown to affect multiple species within the genus Gyps, explaining the simultaneous collapse of several Asian vulture species. Other veterinary NSAIDs have also been identified as potentially harmful.
Additional threats include habitat loss, reduced availability of nesting trees, human disturbance, and localised hunting. Environmental contaminants such as organochlorine pesticides and heavy metals have been detected in tissues and eggs, though these have not been conclusively linked to the main population decline.