for National Geographic News
Several species of Asian vulture will be extinct within a decade, new research warns.
The carrion-eating birds have been on the decline due to exposure to a common livestock drug.
Now a survey of vultures in northern and central India has found the birds' populations have plunged to near-extinction levels—one species is down 99.9 percent since surveys began in the 1990s.
"These species are in trouble," said Todd Katzner, director of conservation and field research at the National Aviary in Pittsburgh, Pennsylvania. "Ten years? It may be sooner."
The study appeared this week in the Journal of the Bombay Natural History Society.
Asian vultures first began to die mysteriously in the 1990s. Eventually experts suspected veterinary diclofenac, a popular and inexpensive anti-inflammatory drug given to livestock in India.
A 2004 study confirmed vultures that ate carcasses of diclofenac-treated cows were dying, most likely from kidney failure. Although the drug was banned in India in 2006, poor enforcement has meant that leftover stocks of the drug still find their way into cattle.
Even a single exposure can be lethal for the birds. "It gets them once and that's it," Katzner said.
Researchers from the Bombay Natural History Society and the Zoological Society of London counted live vultures along roadways in northern and central India between March 2007 and June 2007, covering more than 11,700 miles (18,900 kilometers).
Their data lay out what could be the final chapter for several vulture species.
Oriental white-backed vultures have declined catastrophically: There may now be as few as 11,000 animals, compared to tens of millions just two decades ago.
SOURCES AND RELATED WEB SITES