India | The human cost of the disappearance of vultures

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Forty years ago, there were 40 million vultures in India. Now, there are barely 20,000. The culprit: diclofenac, an anti-inflammatory ingredient found in, for example, Voltaren ointment in Canada. In India, it is used by veterinarians.

“The disappearance of vultures in India is a catastrophe that has hit people’s minds a lot,” says Anant Sudarshan, an economist at the University of Warwick in England who co-authored a study published in July in theAmerican Economic Review.

PHOTO FROM THE UNIVERSITY OF WARWICK WEBSITE

Anant Sudarshan, an economist at the University of Warwick and co-author of the study published in July in theAmerican Economic Review

I personally remember seeing dozens of vultures on animal carcasses every day as a child. We are showing that their absence has very real effects on public health.

Anant Sudarshan, an economist at the University of Warwick and co-author of the study published in July in theAmerican Economic Review

PHOTO ASHWINI BHATIA, ARCHIVES ASSOCIATED PRESS

Stray dogs in Dharamsala, northern India

Vultures were eating dead animals, which in India are often left lying around, Sudarshan said. This increased the circulation of infectious diseases, including rabies, which was spread by stray dogs that were more numerous because of the greater availability of carcasses to eat.

PHOTO FROM WIKIMEDIA COMMONS

In India, vultures played an important role as scavengers in the ecosystem.

Mr Sudarshan and his colleague Eyal Frank calculated that between 2000 and 2005, the disappearance of vultures increased the number of deaths by 100,000 each year in India. That equates to a societal cost of US$70 billion per year. The calculation takes into account India’s lower GDP per capita than the West.

Brevet

The root of the problem was the end of the patent on diclofenac in 1994. The price of the painkiller plummeted and Indian veterinarians began prescribing it to many farmers for mastitis and hoof problems in cattle. When animals died in the fields, vultures were poisoned with diclofenac.

The mystery of the disappearance of Indian vultures was solved by American biologists in 2004, leading to a ban on veterinary diclofenac in India in 2006. But farmers got around the problem by using human diclofenac. In 2020, human diclofenac was also severely restricted.

“Now there is the same problem in Africa,” Mr Sudarshan notes.

Not in Canada

“It’s often talked about at conferences,” says Guy Fitzgerald of the University of Montreal’s School of Veterinary Medicine. “Here in Canada, diclofenac is not approved for veterinary use, except as eye drops.”

PHOTO TAKEN FROM THE UNIVERSITY OF MONTREAL WEBSITE

Guy Fitzgerald, from the School of Veterinary Medicine at the University of Montreal

The painkiller recommended in India as an alternative to diclofenac, meloxicam, is favoured in Canada, according to Merle Olson, an Alberta government veterinarian who has written leaflets on meloxicam. “Meloxicam doesn’t cost much more,” says Dr. Olson. “A lot of times, availability in a market depends on a company creating a production line and then pushing for approval.”

Diclofenac does not have a very harmful effect on North American birds, according to Drs. Fitzgerald and Olson.

Another difference between Canada and India: Here, animals that die are not abandoned in the fields, notes Stéphane Lair, also of the School of Veterinary Medicine at the University of Montreal. Sudarshan adds that water treatment systems are more common in the West than in India.

In Europe, isolated cases of vultures being poisoned by diclofenac have been reported, prompting calls for a ban there too.

Babies and bats

The study’s other co-author, Eyal Frank of the University of Chicago, published the paper in early September in the journal Science a study illustrating the same phenomenon, but with bats in the United States. A fungus is decimating bat colonies in North America, including Quebec. This “white-nose disease” is causing insecticide sales to soar, because bats eat insects and so their absence increases the number of biting insects. Mr. Frank’s analysis shows that in American counties affected by white-nose disease, insecticide sales increase by 31%. This has a detrimental effect on infant health, according to his analysis: infant mortality increases, by an average of 7.9%.

Other examples

Beyond the disappearance of vultures and its effect on human health, this story shows the importance of looking at biodiversity loss from multiple angles, Frank said.

PHOTO FROM THE UNIVERSITY OF CHICAGO WEBSITE

Eyal Frank, University of Chicago

It may be important to check if there is a species crucial to the health of an ecosystem that is affected.

Eyal Frank of the University of Chicago, co-author of the study published in July in theAmerican Economic Review

Are there other examples like this? Frank notes a study showing that in Wisconsin, the reintroduction of wolves reduced car-deer collisions. A 2020 study calculated that the societal benefits of this reduction in car accidents were 63 times greater than the losses to ranchers whose livestock were attacked by wolves.

Vulture researchers also cite a study showing that tree losses linked to the emerald ash borer increased cardiovascular and respiratory diseases in the most affected cities, due to the loss of the filtering effect of ash trees.

Funeral

PHOTO GETTY IMAGES

In this late 19th-century photo, vultures perch on a tower of silence in the Bombay region.

Learn more

• 5 Million More Stray Dogs Linked to Disappearance of Vultures in India

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  38 million more dog bites linked to disappearance of vultures in India

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• 47,000 Additional Rabies Cases Linked to Disappearing Vultures in India

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