|Population||1,500-3,750 (2016 est.)|
|Conservation status||Critically endangered|
The slender-billed vulture (Gyps tenuirostris) is a bird of prey belonging to the subfamily of Old World vultures, Aegypiinae. The species, along with its relatives in the genus Gyps, is severely endangered species due to the use of diclofenac in domestic cattle.
The slender-billed vulture is found in India mainly north of the Ganges River, into southern Nepal, and east into north and central Bangladesh. It was once found further into southeast Asia, with some sightings in Cambodia, Laos, and Burma; it may be extinct in Thailand and Malaysia.
Dry, open-to-partially wooded country is its preferred habitat, and generally in lowland areas. They feed on carrion, subsisting on the carcasses of wild ungulates or domestic livestock. If they are at or near human habitation, it is to take advantage of dumped carcasses, slaughterhouse waste, or remains tossed into garbage dumps.
The slender-billed vulture, as well as all species of Gyps vultures within south and southeastern Asia, has gone through a severe decline in numbers since the 1990s, the population decreasing by 94% between 2000 and 2003 in India alone. The blame fell on the ingestion of carrion meat containing diclofenac, a non-steroidal anti-inflammatory drug (NSAID) meant as an anti-biotic for livestock; the drug causes kidney and renal failure in vultures and is fatal to the birds. Diclofenac is routinely used throughout southern Asia, and in largely-Hindu India its use proved to be particularly problematic where Hindus are forbidden to consume beef. In these regions dead cattle are usually left at the place where they have died, where they are eaten by the vultures.
Diclofenac was banned very quickly in both Nepal and India after recognizing its harmful effect on vultures. This contributed significantly to the fact that with the decline of vultures the population of rats and the number of carrion-consuming feral dogs greatly increased; with both came an increase in the number of rabies cases in humans. Despite the ban, diclofenac is still used in parts of southern Asia.