Oriental White-backed Vulture (Gyps bengalensis), Critically Endangered
Indian Vulture (Gyps indicus), Critically Endangered
Slender-billed Vulture (Gyps tenuirostris), Critically Endangered
In the 1980s, millions of somewhat ugly but still majestic vultures congregated around the carcasses of dead and decaying animals throughout India, Nepal, and Southeast Asia, disposing of them in less than an hour. Today, with their population a mere 0.01% of its former size, carcasses of livestock sit for days or weeks, rotting in the sun.
What happened to the other 99.9%? Poisoned.
Diclofenac is a drug that was commonly used to treat inflammation and arthritis in livestock. When animals receiving the drug died, vultures would come to feast. A few days later, their kidneys would fail and death would follow shortly. Diclofenac is, as far as anyone can tell, the sole culprit for the decline of these useful birds.
Diclofenac has been banned for veterinary use in India, Nepal, and Pakistan since 2006, but is still available for human use--and some farmers still use it for their livestock.
Now, another drug commonly used to treat livestock, ketoprofen, has been shown to have similar effects to diclofenac. Ketoprofen is not used as widely, but it's becoming more popular. Although it's not as toxic as diclofenac, studies and modeling have shown that even with very small numbers of poisoned carcasses, massive declines in vulture populations would occur.
Conservation organizations, including the Bombay Natural History Society, the Royal Society for the Protection of Birds, and Birdlife International, are advocating the use of meloxicam. Though this drug is more expensive, it is the only drug known to be safe for vultures. Other drugs exist, but their effect on vultures is unknown.
Captive breeding centers for Vultures have been established, as well as Vulture restaurants, where undrugged carcasses are left out for the birds. There have been some successes with captive breeding, but the birds will probably not be released until harmful drugs are no longer a threat.