The vulture population has, in fact, witnessed one of the "most dramatic declines" of a wild species in human history, says the UN report. It regretted that a veterinary drug responsible for their deaths continues to be available in the market despite a ban. "Once present in numbers ranging over tens of millions across India, Pakistan, Bhutan, Nepal and Bangladesh, vultures today are on the brink of extinction," the United Nations progress report on the state of global biodiversity says.