How Diclofenac Nearly Drove India's Vultures to Extinction, and What the Recovery Programme Has Actually Achieved

Through the 1990s, vulture populations across South Asia fell off a cliff so steeply that ornithologists initially suspected a new disease. The Gyps vulture, the genus that includes the white-rumped, long-billed, and slender-billed species, had been among the most numerous large raptors on earth. Surveys conducted by the Bombay Natural History Society found that between 1992 and 2007, India's white-rumped vulture population declined by approximately 99.9 percent. The long-billed and slender-billed species fell by over 97 percent. These are not rounding errors. These are functional extinction numbers.
The cause, confirmed in a 2004 paper published in Nature by researchers including Lindsay Oaks and a team from the Peregrine Fund, was diclofenac: a non-steroidal anti-inflammatory drug widely used by farmers to treat lameness and fever in cattle. Vultures feeding on the carcasses of cattle treated with diclofenac before death absorbed the drug through contaminated tissue. Their kidneys failed within days. Visceral gout, uric acid crystals depositing in organ tissue, killed them before they could disperse. A single treated carcass could kill every vulture that fed on it.
Vultures are not incidental to an ecosystem. They are load-bearing. The stomach acid of a Gyps vulture registers at a pH of roughly 1, lower than battery acid, which destroys anthrax spores, botulinum toxin, and rabies virus that would survive in any mammalian scavenger. A carcass a vulture strips in 30 minutes can take a feral dog or rat weeks to consume, and those animals are reservoir hosts for rabies and plague.
A 2008 study by Anil Markandya and colleagues, published in Ecological Economics, estimated that the vulture collapse contributed to a surge in India's feral dog population of roughly seven million animals, and linked this to an increase in human rabies deaths costing the health system billions of rupees annually. The numbers are modelled, not measured directly, but the directional logic is hard to dispute. Parsis in Mumbai reported that the Towers of Silence, where the community traditionally exposes its dead for sky burial, became unusable as vulture numbers collapsed. The ecological failure had cultural consequences no one had mapped in advance.

India banned veterinary diclofenac in 2006. Nepal and Pakistan followed. The ban was the right call, and meloxicam, a structurally similar anti-inflammatory that is safe for vultures, was identified as a viable substitute. The Bombay Natural History Society, working with the Royal Society for the Protection of Birds, ran field trials confirming meloxicam's safety for Gyps species.
The problem was enforcement and market penetration. Diclofenac manufactured for human use, legally sold in multi-dose vials, continued to be diverted for veterinary use for years after the ban. A 2011 survey published in PLOS ONE, led by Vibhu Prakash of the BNHS, found diclofenac still detectable in a significant proportion of cattle carcasses at key vulture feeding sites. The drug had not left the food chain simply because it had left the approved veterinary list. India moved to ban the large-volume human formulations in 2015, which substantially reduced the diversion route, though monitoring data suggests residual contamination persisted beyond that point.

India established nine vulture conservation breeding centres, operated jointly by the BNHS and state forest departments, with facilities at Pinjore in Haryana, Rani in Assam, and Bhopal in Madhya Pradesh among others. The programme focuses on white-rumped, long-billed, and red-headed vultures. Captive breeding for raptors is slow work: Gyps vultures reach sexual maturity at five to seven years and typically raise one chick per year. The centres have produced viable breeding pairs and documented successful hatching across multiple seasons.
Reintroduction, however, has not happened at scale. The standard protocol for releasing captive-bred raptors requires the wild population to have stabilised and the primary threat to be controlled. Conservationists at the BNHS have been cautious about releasing birds into landscapes where diclofenac contamination cannot be verified as negligible. A vulture bred in captivity, released into a range where one contaminated carcass awaits, is a conservation loss that takes seven years to replace. The breeding centres are an insurance population, not yet a reintroduction engine.

Field surveys from the past decade show some recovery in localised areas, the Pench and Kanha landscapes in Madhya Pradesh have reported modest increases in white-rumped vulture sightings, but the overall population remains a fraction of pre-collapse levels. Recovery at the scale of the original extinction has not occurred.
The honest accounting is this: the diclofenac ban stopped the active killing. Meloxicam adoption by farmers, though incomplete, reduced the contamination rate in carcasses. The captive breeding programme preserved genetic diversity and kept the species from crossing into unrecoverable territory. These are real achievements, and the conservation community that pushed for them, the BNHS, RSPB, and state wildlife departments, deserves credit for moving faster than most wildlife crises allow.
What the programme has not achieved is a self-sustaining wild population. The Jatayu Conservation Breeding Centre in Pinjore has birds. The skies over most of the Gangetic plain do not. For scavengers that once numbered in the tens of millions, a few hundred captive individuals and a modest wild uptick in protected landscapes is a beachhead, not a restoration.
The vulture's disappearance exposed something that took years to name: the species had been doing sanitation work for every ecosystem it inhabited, and no one had priced that service until it was gone. The recovery programme has kept the option of restoration alive. Whether India's agricultural landscape becomes safe enough for vultures to actually live in it again is a question the breeding centres cannot answer on their own.