In the past several years White-Backed Vulture numbers in India have dropped by 95%. This is a serious cultural problem, as well as being a tragedy for the bird species itself.

These magnificent birds have a bad reputation in the west however in India they perform the important function of consuming the remains of the dead that are left on a hill called "The Tower of Silence" near Mumbai. The burial practice, carried out by the Parsi, that has been in place for over 200 years is under threat because of the declining numbers of White-backed Vultures. The area is also experiencing a dramatic rise in the number of rabies-riddled feral dogs to fill the niche being vacated by the vultures.

Bird virologist J. Lindsay Oaks of Washington State University in Pullman is proposing that an anti-inflammatory drug called diclofenac may be poisoning the vultures. Vets in India use the painkiller in cattle. By eating cattle carcasses, birds might be building up toxic levels of the drug. Cattle carcasses are available to the birds because the cow is sacred and not consumed by humans.

Andrew Cunningham of the Zoological Society of London argues that the vulture symptoms point more to an infectious desease being the cause.

Research is continuing.