Only a decade ago, millions of Asian vultures lived in Pakistan, India, and Nepal. These enormous raptors provided an effective method of removing dead livestock, preventing the spread of diseases. They played a similar role with human corpses, ritualized in the "sky burials" of the Parsi religion.
Then huge numbers of these birds began dying mysteriously starting about a decade ago. They're now teetering on the edge of extinction. No one knew why until last May, when a veterinarian with the Peregrine Fund discovered the culprit: a pain-relief medication routinely administered to cattle. Birds that ate dead cattle treated with the drug were dying in massive numbers. The veterinarian, Lindsay Oaks, has warned that if nothing is done, these species could be extinct in months.
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The toll on the vultures has been enormous. Three species - the oriental white-backed vulture, long-billed vulture, and slender-billed vulture - have declined by 92 to 99 percent over the past decade, researchers say. And the slender-billed vulture may actually already be extinct.
The annual mortality rate of these species is now a staggering 30 to 60 percent, says Bill Burnham, president of the Peregrine Fund, in Idaho. "Based on this rate of decline, this breeding season could be our last," he says."
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http://csmonitor.com/2004/0304/p17s01-stss.html