Indian Vulture

The Indian vulture, also known as the long-billed vulture (Gyps indicus), is a large scavenging bird of prey native to the Indian subcontinent. It belongs to the Old World vultures within the family Accipitridae and plays a crucial ecological role as a natural cleaner of the environment. Once widespread and abundant, the species has undergone one of the most rapid population declines ever recorded in birds and is now listed as Critically Endangered on the IUCN Red List. The Indian vulture crisis has become a landmark case in conservation biology, highlighting the unintended ecological consequences of veterinary pharmaceuticals.
The species is primarily associated with open landscapes, cliffs, and human-dominated environments where livestock carcasses are available. Its sharp decline since the 1990s has had profound ecological, social, and public health implications across South Asia.

Taxonomy and Classification

The Indian vulture belongs to the genus Gyps, a group of large Old World vultures adapted for soaring flight and obligate scavenging. The genus name Gyps is derived from the Ancient Greek gýps, meaning vulture, while the species epithet indicus is Neo-Latin for “Indian”, reflecting its geographic origin.
Until 2001, the slender-billed vulture (Gyps tenuirostris) was considered a subspecies of the Indian vulture. Advances in molecular biology, including nuclear and mitochondrial DNA analysis, demonstrated sufficient genetic divergence to justify its recognition as a separate species. The Indian vulture also shares part of its range with the white-rumped vulture (Gyps bengalensis), another critically endangered species affected by similar threats.

Distribution and Habitat

Historically, the Indian vulture ranged from southeastern Pakistan across much of India to Indochina and the northern Malay Peninsula. Today, it is extinct in Southeast Asia and survives mainly in central and southern India, particularly south of the Gangetic plains. Smaller populations persist in south-western Pakistan, Nepal, and Bangladesh.
The species occupies a wide variety of habitats, including semi-deserts, dry foothills, open plains, agricultural landscapes, and areas close to human settlements. It is frequently observed near villages, slaughterhouses, garbage dumps, and carcass disposal sites, where food availability is high. Indian vultures are non-migratory but can travel hundreds of kilometres in a single day while scavenging. Nesting typically occurs on cliffs and rocky outcrops, although high buildings and, rarely, trees are also used.

Physical Description

The Indian vulture is a medium-sized vulture with a bulky body and broad wings adapted for soaring. Adults have pale brown body and wing coverts, contrasted with darker flight feathers. The thighs are white with scattered downy feathers, and the tail is relatively short.
A distinctive feature is its small, semi-bald head and long, mostly featherless neck. The head is dark brown, with dark eyes and a long yellowish bill topped by a pale greenish-yellow cere. The lack of feathers on the head and neck is an important adaptation that helps keep these areas clean while feeding on decaying carcasses and also assists with thermoregulation.
The Indian vulture measures approximately 80–95 cm in length, with a wingspan of around 215–230 cm. Adults typically weigh between 5 and 6.5 kg, making them smaller and less bulky than the closely related Eurasian griffon vulture. This difference is reflected in their slimmer wing coverts and overall build.

Behaviour and Ecology

Indian vultures are powerful fliers that rely on thermal convection currents to soar efficiently. They can glide at speeds of around 35 km/h and may remain airborne for six to seven hours continuously while searching for food. They are usually seen singly or in small groups and may associate with other vulture species at carcasses or roosting sites.
The species nests mainly on cliffs, forming loose colonies rather than dense aggregations. Roosting and nesting sites are often reused over many years, provided disturbance remains low.

Diet and Feeding

As an obligate scavenger, the Indian vulture feeds almost exclusively on carrion, particularly the carcasses of domestic cattle and other large mammals. It relies primarily on its keen eyesight to locate food, often following other scavengers or raptors to potential feeding sites.
The species plays a keystone ecological role by rapidly removing carcasses from the environment, thereby limiting the spread of pathogens and reducing the availability of carrion to less efficient scavengers. At feeding sites, competition can be intense, and individuals may engage in aggressive interactions to secure access to flesh. Being smaller than some other vulture species, Indian vultures sometimes yield to larger competitors.

Lifespan and Mortality

Indian vultures are long-lived birds, with a lifespan of 40–45 years under favourable conditions. They reach sexual maturity at around five years of age. In recent decades, increasing proximity to human infrastructure has exposed them to additional mortality risks, including road collisions, electrocution on power lines, and strikes with trains and wind turbines.
However, the most devastating cause of mortality has been exposure to non-steroidal anti-inflammatory drugs (NSAIDs), particularly diclofenac.

Reproduction and Breeding

Breeding pairs are generally monogamous. Nest building begins around September, with the breeding season extending from November to March. Nests consist of large platforms made of sticks and twigs, lined with leaves and often supplemented with fresh green foliage, which may help deter parasites.
Only one egg is laid per breeding season. The egg is white or lightly mottled with rusty markings. Both parents share incubation duties, and the egg hatches after approximately 50 days. Nests are frequently located near water sources and are usually situated at elevations above 900 metres, which may help regulate humidity and reduce disturbance.

Conservation Status and Population Decline

The Indian vulture has been listed as Critically Endangered since 2002. Between the early 1990s and mid-2000s, populations declined by an estimated 97 percent across the Indian subcontinent. Current estimates suggest only 5,000 to 15,000 mature individuals remain in the wild.
The primary cause of this catastrophic decline was identified as diclofenac poisoning. Diclofenac, widely used in veterinary medicine to treat livestock pain and inflammation, proved lethal to vultures that fed on carcasses of treated animals. Even trace amounts caused acute kidney failure, leading to death within days. Modelling studies showed that contamination of less than 1 percent of livestock carcasses was sufficient to cause population collapse.

Ecological and Socioeconomic Impacts

The loss of Indian vultures had severe consequences beyond biodiversity. With fewer vultures to remove carcasses, large numbers of animal remains were left to rot, contaminating water sources and increasing disease risks. This ecological vacuum contributed to a dramatic rise in feral dog populations, leading to millions of additional dog bites and tens of thousands of human deaths from rabies, alongside substantial economic costs.