By IANS,
Washington : Political barriers in India and Pakistan are hampering efforts to save the critically endangered Asian vulture from extinction, whose numbers are down to a few thousand from tens of millions.
“One of my goals is to raise awareness of the problem and to increase political will in India and Pakistan to get this matter resolved,” said Jeff A. Johnson, co-author of a study on the subject, who was earlier with the University of Michigan.
The absence of vultures poses a direct threat to public health as well, as uneaten carcasses provide breeding grounds for bacteria and attract feral dogs, which may spread rabies and other diseases.
The oriental white-backed vulture, with a seven-foot wingspan, was an awesome sight in South Asia until the mid-1990s, when whole populations began to collapse.
Researchers eventually traced the cause to an anti-inflammatory drug, diclofenac, that is used to alleviate arthritis-like symptoms in livestock but is toxic to vultures.
Vultures that feed on carcasses of animals treated with the drug die of kidney failure within a day or two after eating the tainted meat. And although India, Nepal and Pakistan outlawed its manufacture in 2006, diclofenac is still available, and birds are still dying.
While the death of an unattractive bird that scavenges for a living may not sound like a great loss, vultures have important cultural and religious significance in south Asia.
Ancient Zorastrians or Parsis hold earth, fire and water sacred, and to avoid contaminating them, they dispose of their dead by placing them on “Towers of Silence,” where vultures consume the remains. Besides, the vulture saint Jatayu is an important figure in Hindu mythology.
Johnson and co-workers used museum specimens collected before the decline began, along with recent feather and tissue samples from birds in Pakistan’s last remaining wild breeding colony, to see how genetic diversity in the wild population has changed as the population has plummetted.
Then, assuming captive populations of various sizes, they used computer simulations to determine how large captive populations must be to preserve genetic diversity.
The analysis showed that while there was still a fair amount of genetic diversity in the wild population two years ago when their last samples were obtained, current captive populations are not large enough to maintain that diversity if the wild populations are wiped out – a fate that seems inevitable if people keep using diclofenac.
“We know the problem, and we know the solution,” said Johnson, who was an assistant research scientist at U-M and recently accepted a position as an assistant professor at the University of North Texas in Denton. “We just need to get diclofenac out of the environment and more birds into protection before it is too late.”
The Peregrine Fund, an organisation that works to conserve birds of prey in nature, is trying to prevent the birds’ extinction, but it’s an effort that requires money and international cooperation, both of which can be problematic in the vultures’ home countries.
The study was published online in Biological Conservation.