The near extinction of vultures in India during the 1990s led to the spread of disease-carrying pathogens – and may have killed half a million people, according to a new study.
The paper, to be published in an upcoming issue of the American Economic Review, estimates that the related public health crisis between 2000 and 2005 cost the Indian government nearly $70 billion a year.
Vultures were once widespread in India, acting as "nature's sanitation service", said The Economist. But in 1994 farmers began giving their livestock a painkiller called diclofenac. When they disposed of dead livestock the vultures who fed on the carcasses were poisoned by the anti-inflammatory drug, dying within weeks.
In one decade India's vulture population fell from 50 million birds to just a few thousand: the fastest collapse of a bird species in history.
Cattle bodies piled up around tanneries and fields "became carcass dumps" for feral dogs and rats, said the journal Science, leading to the spread of disease. In districts that were "highly suitable to vultures" there was an average increase in human deaths of 4.2%. That implies about 104,386 additional deaths each year, or half a million in total.
The vulture wipeout was later attributed to diclofenac and India banned the use of the drug in 2006. Pakistan and Nepal followed suit. But India's vulture population is unlikely to ever completely recover.
Images of their "blood-splattered bills" tend to "evoke less sympathy" than "majestic tigers, adorable pandas" or other staples of wildlife conservation campaigns, said The Economist.
But "conserving these animals should be a priority ... they may not be cute or cuddly, but they are important". | 
