By Sudipto Sanyal
The Jatayu Conservation Breeding Centre, the world’s largest facility for protecting and breeding vultures, is hidden in a dense forest of sal and ash trees outside the town of Pinjore in northern India. You get there by following a rutted dirt track that even Google Maps doesn’t know about. Santosh Kumar’s family has lived in a nearby village for almost ten generations. For much of that time, vultures were a daily sight throughout the state of Haryana and, indeed, much of India. “When I was ten and an animal died,” recalled Kumar, a slight 46-year-old, “hundreds of the damn birds would gather.”
Like many Indians who live under skies that are no longer darkened by vultures, Kumar, who runs a small shop at the edge of the forest, speaks of the birds wistfully—and conspiratorially. “All the vultures disappeared after an earthquake in Pakistan and never came back,” he told me while handing over an ice-cold bottle of water. “The Pakistanis lured them with rotting corpses.”
Given the suddenness and scale of the vultures’ disappearance, it’s not surprising that the mind reaches for such far-fetched explanations. Sometime in the 1990s vultures started dropping dead throughout India—first in the thousands, then in the millions. By 2007 more than 99% of the estimated 40m vultures in South Asia had died. This was an example of what ecologists call a “functional extinction”: a population so diminished that it can no longer fulfill its role in the ecosystem.
At first, biologists were baffled. Livestock carcasses—vultures’ main source of food—were tested for pesticides, but none appeared to be present. Then the autopsies of dead vultures began to show the presence of visceral gout, a disease that encrusts the birds’ internal organs in a crystalline shroud. This prevented the vultures’ kidneys from expelling uric acid, causing them to die of renal failure.
The culprit turned out to be diclofenac—a non-steroidal anti-inflammatory drug (NSAID) typically prescribed to large animals, including humans. By the early 1990s, diclofenac was the cheapest and most widely used NSAID in India. Vultures, as nature’s disposal system, were scavenging the remains of dead cattle and ingesting traces of the drug.
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Until the diclofenac scourge of the 1990s, vultures were responsible for the disposal of roughly 27.5m cow carcasses in India each year. In the vultures’ absence, rats and feral dogs have come to fill the scavenging void, albeit far less efficiently. This, in turn, has fuelled the spread of animal-borne diseases such as rabies, as well as other issues related to poor sanitation. Eyal Frank and Anant Sudarshan, economists from the University of Chicago and the University of Warwick, respectively, have calculated that more than 500,000 Indians died between 2000 and 2005 alone because of the loss of vultures’ scavenging services. They reckon that these premature deaths cost the country close to $70bn each year—roughly 1.7% of the country’s GDP—during that period. (Given that the vulture population hasn’t recovered to pre-diclofenac levels, it’s likely that such human and economic costs continue to be incurred.)