India is facing a huge economic and social problem: vultures. Or rather, their loss. The decline in the population of these voracious predators, which has in some cases exceeded 90% in recent years, has become a challenge for Narendra Modi’s country that goes far beyond the environmental impact. This is reflected in a study recently published in the journal of the American Economic Association (AEA), which leaves two figures on the table: the collapse of vultures has already cost India 500,000 human lives and a bill of more than $69,000 million per year. And this is between 2000 and 2005.

The question is… How can this be reversed?

Fewer (much fewer) vultures. The study, by researchers Eyal Frank and Anant Sudarshan, is based on a resounding fact: a 95% collapse in vulture populations in India. Some estimates go even further, saying that they have gone from 50 million to 20,000 in a relatively short period of time. “This is the fastest population decline of any bird species on record and the largest population decline in the United States since the extinction of the passenger pigeon,” the experts commented.

The most significant losses were caused by white-backed, Indian and red-headed vultures, with declines ranging from 91% to 98%. To a lesser extent, Egyptian and fawn also declined.

A name: cyclofenacResearchers are clear about what caused such a disaster. The collapse of vulture populations in India, down more than 90 percent, is largely attributed to the popularization in the 1990s of diclofenac, a cheap and accessible analgesic that farmers began giving to their cattle to combat the condition.

The problem was that the drug was toxic to vultures, which indirectly ingested it by feeding on cattle carcasses. “When vultures of the Gyps genus consume carcasses containing traces of diclofenac, they develop kidney failure and die within weeks,” Frank and Sudarshan warn.

“Mass death”“After the introduction of veterinary diclofenac in 1994, reports of dead vultures in the wild began to pile up,” they recall. The first report sounding the alarm about “mass die-off” of birds of prey dates back several years, to 1996.

Indian farmers have been without access to veterinary diclofenac for almost two decades, but vulture populations have yet to recover. The BBC reports that while declines have slowed in some areas, at least three species have suffered a significant decline of between 91 and 98 per cent.

“The cause of the disaster was addressed in 2004, and veterinary use of diclofenac was banned in India in 2006. However, research through 2018 has documented the drug’s continued illegal use in livestock,” warns the Vulture Conservation Foundation (VCF). The Indian vulture population may not recover from the disaster because of the 2006 ban. It takes years for vultures to reach sexual maturity and produce very few offspring, and survival is not guaranteed.

Fewer vultures… hundreds of thousands of human deaths. That’s the surprising connection that Frank and Sudarshan’s study makes: The extinction of vultures in India had a devastating effect on their populations, measured in deaths. The study attributes the loss of predators to 100,000 human deaths each year between 2000 and 2005, compared with about 500,000 before India banned diclofenac for veterinary use.

“On average, even when controlling for softer temporal trends, we estimate that human deaths increased by more than 4% between 2000 and 2005, when vultures reached newly collapsed population levels,” said the researchers, who are at the Harris School of Public Policy and the University of Warwick.

A matter of life… and money. Frank and Sudarshan overlook another equally interesting and revealing fact: the loss of vultures has cost the country dearly. Hugely. Millions. Tens of millions. Their calculations suggest that the deaths and economic costs associated with premature deaths amount to $69.4 billion a year. “The extinction of vultures in India provides a clear example of the irreversible and unpredictable costs that the loss of a species can have on humans,” Professor Sudarshan warns.

So what is the reason? It may seem strange that fewer vultures could mean hundreds of thousands of human deaths and a bill in the tens of thousands of dollars a year, but the relationship becomes clearer when you understand the role that predatory scavengers play as a “natural cleanup service,” Frank says. Vultures feed on carcasses that contain bacteria and pathogens that could pose a threat to humans. “Without them, diseases can spread,” the Chicago expert recalls.

“In a country with more than 500 million livestock and no infrastructure to dispose of dead animals, the winners depended on vultures as environmental disinfectants,” both authors warn. “In their absence, animal carcasses linger outside or are dumped in water by farmers, creating a greater risk of disease.”

While this logic is not alarming in itself, another is added: without vultures to feed on carcasses left by livestock farmers, the amount of carrion available to dogs and rats increases, creating a new threat: both of which represent a “significant resource.” Experts say rabies infections are on the rise.

Mortality rates and vaccines. To conduct their study, the researchers used a surprising variety of data sources. They took into account, among other things, analyses that looked at human mortality rates before and after vulture population collapses, sales of rabies vaccines, wild dog censuses, or water pollution levels. One of the most interesting findings, the BBC reported, was that this effect was most pronounced in urban environments, where there was livestock farming and body dumping.

Sudarshan warns: “The extinction of vultures in India provides a particularly clear example of the irreversible and unpredictable costs that the loss of a species can have on humans.” There are also “other human activities” that affect ecosystems, such as deforestation, wildlife trade or human-induced global warming, which ultimately affect our own lives. The vulture leaves a clear example.

Big problem, difficult solutions. Another of the amazing results of the study. The extinction of vultures in India is not just a problem of species loss or the resulting loss of human life. If the situation is so serious, it is also because it is not an easy problem to solve.

Frank and Sudarshan suggest that one possible solution would be to create a network of incinerators responsible for disposing of the carcasses, thereby replacing the role naturally played by vultures, but this solution would present two major obstacles: first, its high cost, estimated at around $768 million per year, and second, its environmental impact, which would further deteriorate air quality and require the carcasses to be transported long distances, is equally alarming.

Image | Yerkurt6886 (Flickr)

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