The Vulture Collapse and Its Human Cost

How a cheap cattle painkiller wiped out India's vultures in the 1990s and 2000s, and how economists estimated the surprisingly large cost in human lives.

In the 1990s, India had tens of millions of vultures. They played an unglamorous but vital role: eating the carcasses of dead cattle and other animals. Within about a decade, their populations collapsed by more than 95 percent.

The cause

Scientists discovered the culprit was diclofenac, a cheap painkiller widely given to cattle from the mid-1990s. When vultures ate carcasses of treated animals, the drug caused kidney failure, killing them.

India banned diclofenac for veterinary use in 2006, and later restricted similar drugs.

The ecological consequences

Without vultures:

Carcasses rotted for longer.
Feral dog populations rose, feeding on carcasses.
Rabies risk increased, as dogs spread the disease.
Disease-causing bacteria could spread into water.

The human cost

In a 2024 study, economists Eyal Frank and Anant Sudarshan compared districts that had many vultures before the collapse with those that had few. They estimated that the vulture collapse caused around 500,000 additional human deaths between 2000 and 2005, largely through the spread of diseases and contaminated water, with an estimated economic cost of tens of billions of dollars a year.

Why this matters

Ecosystem services can be invisible until they disappear.
Unintended consequences: a drug that helped cattle had devastating effects on wildlife and people.
Externalities: farmers using diclofenac didn’t bear the costs imposed on society.

Recovery efforts

Captive breeding centres for vultures.
Vulture safe zones where harmful drugs are removed from use.
Banning other harmful veterinary drugs.

Vulture numbers remain far below historical levels.

The missing cleaners

In a village where vultures once cleaned carcasses within hours, dead cattle now lie rotting for days. Stray dogs multiply and some carry rabies. Children are bitten, and water sources are contaminated. The loss of a bird few people noticed has real human costs.

Thinking losing a species only matters to conservationists

The vulture collapse caused large increases in human deaths, showing how ecosystem services protect people.

Key takeaways

India's vultures collapsed by more than 95 percent after diclofenac use in cattle.
India banned veterinary diclofenac in 2006.
Economists estimated about 500,000 extra human deaths from 2000 to 2005.
The case shows the hidden value of ecosystem services and unintended consequences.