Something else happened in ’93 that went unnoticed. The patent on a 20-year-old drug expired. This drug was the common painkiller diclofenac, found in products like Volini, Voveran, etc.Until 1993, its supply was controlled by the Swiss pharma firm Ciba-Geigy (now Novartis), but with the patent over, generic production took off. Prices crashed everywhere. In Sri Lanka, for example, generic diclofenac cost Re 1, as against Rs 8 for the branded product in August 1995.
Livestock use starts
It happened in India, too. After all, Indian generic manufacturers were driving down diclofenac’s price. The result was that in 1994, veterinary use of diclofenac became common. Farmers started using it to treat “injuries, inflammations and fevers in wounded or sick animals”. It made sense because diclofenac was cheap, easily available, and worked in 15 minutes.
Vultures annihilated
But then, something else that nobody had imagined happened. Indian vultures started dying in large numbers. By the time the link between vulture deaths and diclofenac in animal carcasses was discovered, it was too late. India’s vulture population was practically annihilated. From almost 40 million in the early 1990s, vultures became rare in the early 2000s.
But that’s an old story. Now, a new report by researchers Eyal Frank and Anant Sudarshan claims the loss of vultures indirectly led to hundreds of thousands of human deaths.
$70bn lost every year
In their paper titled ‘The Social Costs of Keystone Species Collapse: Evidence From The Decline of Vultures in India’, Frank and Sudarshan say: “The functional extinction of vultures…increased human mortality by over 4%.”
It might not sound like a huge change, but we are talking about human lives here, not car mileage. If 100,000 people die every year in a country, a 4% change means 4,000 additional deaths. The researchers claim “an average of 104,386 additional deaths a year” between 2000 and 2005. They have also estimated the economic loss to the country from these additional deaths: almost $70 billion per year.
‘Keystone’ of environment
Humans drove cheetahs to extinction and brought tigers to its verge without suffering serious consequences. So, why did the near-extinction of vultures prove so harmful? The answer to that question lies in the word ‘keystone’ in the title of Frank and Sudarshan’s paper. They describe vultures as a keystone species because “if they are removed, the effects on the ecosystem are potentially large”.
That’s not an exaggeration. For a moment, go back to Carter’s photograph of the Sudanese child. Why was the vulture waiting for it to die? The answer is: vultures have evolved as scavengers, not predators, although occasionally you hear rumours of them killing livestock.
When it comes to scavenging, they are unmatched. Frank and Sudarshan say a flock of vultures – the precise word is ‘committee’ – can reduce a 385kg cow carcass to bones in 40 minutes. Dogs and rats also scavenge but they aren’t so efficient. They leave behind a lot of flesh on the bones to rot, and dogs spread rabies themselves.
Sanitary flying squad
So, for thousands of years, vultures shouldered the municipal task of scavenging in India’s towns and villages. Farmers reared animals, and when the animals died vultures promptly took care of the carcasses. India has always had very large livestock populations – 500 million, per the 2019 livestock census – and the report estimates the 40-odd million vultures in India till 1993 could have consumed meat equivalent to the weight of 27 million cows in a year. That’s 10.4 billion kilos of meat.
By removing millions of tonnes of flesh from the environment, vultures not only contained the spread of pathogens but also curbed the numbers of other scavengers like rats and feral dogs, which spread the deadly rabies virus.
As the vulture population melted away, Frank and Sudarshan say ‘animal landfills’ emerged outside towns and villages. Burying carcasses deep in the ground or incinerating them was expensive, so they were dumped “on the outskirts of population centres across India”. Sometimes, the carcasses were dumped in water, or fluids leaching from their rotting bodies flowed into water bodies.
Clear increase in deaths
Frank and Sudarshan carefully examined death rates before and after the decline of vulture populations. For their analysis, they separately studied areas that originally had large vulture populations, and those that didn’t. The data showed areas that were unsuitable for vultures used to have marginally higher death rates (1.2 extra deaths per 1,000 people) between 1988 and 1993.
The researchers suggest this might have been because the areas with fewer vultures – cooler and drier places – had a problem of rotting carcasses leading to disease and death.
But when vulture numbers fell dramatically in 1996, the death rate in areas that had always had bigger vulture populations became higher by “0.65 deaths per 1,000 people”. By 2005, the gap had increased to 1.4 additional deaths per 1,000 people.
And this “sanitation shock” due to the disappearance of vultures was felt more strongly in urban areas that didn’t have vast open spaces to dispose of carcasses. Also, their “significantly higher population density, and network infrastructure such as drains allowing pathogens and waste to spread rapidly” made the situation worse. Frank and Sudarshan say, “We find that urban areas experienced a larger increase in death rates relative to the combined sample.”
Stray dog menace
Dog bites and rabies are big problems in India. On July 30, the government informed Parliament that there were 3 million dog bite cases in 2023, and 4.7 million rabies shots were given. Still, 286 people died.
The study suggests India’s dog population multiplied when vulture populations declined. The same dead animals that vultures removed meticulously were now available to dogs to devour. And dogs, unlike vultures, breed rapidly.
Frank and Sudarshan cite the spurt in demand for rabies shots after 1996 as evidence of a sharp increase in dog numbers, following the decimation of vulture populations.