Asian white-backed vulture  (Gyps bengalensis)

The Asian white-backed vulture was once the commonest vulture in the Indian subcontinent and was abundant throughout its range (4). Populations in South East Asia had all but disappeared by the mid-20th century. These declines have been attributed to direct causes such as hunting and live capture, as well as the indirect effects of a reduction in carrion as hygiene improved across the region (5). Having suffered an extremely rapid decline in numbers due to a previously unknown cause, the Asian white-backed vulture is in danger of imminent extinction without immediate conservation action. By 2000, dead and dying Gyps vultures were being found so frequently in Nepal and India it was thought that they were suffering from an epidemic. The unnaturally high death toll was thought to be caused by a fatal virus, but testing has revealed that vultures are suffering from kidney failure following the consumption of cattle that had previously been treated with the anti-inflammatory drug, diclofenac (2). In fact, the decline is a result of a lethal level of the drug in a small proportion of the ungulate carcasses available to vultures, but as vultures travel long distances to reach carrion, a considerable proportion of the population has been affected (6).

The full extent of the decline of Gyps vulture species is already felt by humans, as rotting carcasses remain untouched, posing a health hazard, as well as encouraging feral dog populations which carry rabies (7).

It is necessary to prevent exposure of vultures to livestock carcasses that have been contaminated with diclofenac, and to find an alternative replacement drug (7). Government commitment to the control of the use of the drug is crucial, but until it has been entirely removed from the environment, a collaboration of bird protection organisations plan to take all Asian white-backed vultures into captivity for the next 20 to 30 years to avoid further deaths, which would further reduce the chance of a successful recovery of this already rare species (7).