Three species of vultures endemic to South Asia including Bangladesh, oriental white-backed vulture (Gyps bengalensis), long-billed vulture (G. indicus) and slender-billed vulture (G. tenuirostris), are listed as being threatened with extinction after rapid population declines in this region. Populations of three Gyps vulture species in parts of their ranges in South Asia fell by more than 95 percent in the 1990s, and all are now classified as Critically Endangered. Unless major steps are taken, all three species could soon be facing extinction. The white-rumped vulture -- once the most populous large bird of prey -- is under particular threat, having declined by 99.9 per cent. During the 1980s the oriental white-backed vulture was so abundant in this region that it was probably the most common large bird of prey in the world. More than 97 per cent of vultures have disappeared from this region's skies in the past 15 years -- the fastest decline ever recorded in a bird population anywhere in the world. Only about 10,000 still exist in the wild in the sub-continent, down from tens of millions in the 1980s.
When South Asia's vulture numbers began to plunge in the mid-1990s, researchers were mystified. By the time the cause is identified -- widespread use of diclofenac, a non-steroidal anti-inflammatory drug that had become a popular treatment for ailing livestock to ease pain. Vultures in Bangladesh are on the verge of extinction because this drug is still being used to treat suffering cattle. The endangered birds eat the remains of the drugged animals and suffer kidney failure and visceral gout, which are usually fatal. When numbers of the bird crashed to a few thousand across the entire subcontinent the impact was dramatic. Rotting carcasses stunk up the villages and towns, incubating disease. Populations of feral dogs scavenging on the meat bonanza exploded, and the dogs also spread diseases, including rabies. Vultures' culinary tastes have given them a sinister reputation but they perform a crucial role. When an animal dies, it becomes a breeding ground for all sorts of pathogens. The vultures used to eat off the animals before bacteria and fungus could develop, preventing the spread of rabies, anthrax and many other diseases.
The governments of India, Pakistan and Nepal commenced actions to prevent the contamination of vulture food supplies with the drug in 2006 and recently Bangladesh also formally banned this drug. It is now illegal to import, manufacture, retail or use diclofenac for veterinary purposes but the continued presence of residues of the drug in animal carcasses must have therefore been caused by illegal veterinary use. Pharmacies often dispense both human and veterinary medicines, in which case their holding stocks of human diclofenac is not an offence, a study found run by RSPB (Royal Society for the Protection of Birds).
To provide a safer environment for vultures in South Asia, scientists recommend reducing the size of vials of diclofenac meant for human use, increasing the costs, and taking action against pharmaceutical manufacturers and pharmacies flouting the diclofenac ban. The drug was banned five years ago in India, Pakistan and Nepal in 2006, but pharmacies continue to sell it illegally to treat suffering cattle, a study published in 2011 International Journal, Oryx has revealed. Lead author and principal conservation scientist at the RSPB, Dr Richard Cuthbert, stated: “The ban is still quite easy to avoid because human formulations are still freely for sale in large vials which are convenient for use on large animals like cattle and clearly not suitable for human use. Preventing the misuse of human diclofenac for veterinary use remains the main challenge in halting the decline of endangered vultures.”
While the research shows that there is still widespread availability of diclofenac after the ban, encouragingly it also shows an increase in meloxicam (found in 70 per cent of pharmacies). There is also evidence that untested drugs such as nimesulide are more widely available in the market. The effects these drugs have on vultures are yet unknown. Ketoprofen, an alternative that has been tested and shown to be deadly to vultures has still not been banned. Firm action at government level against pharmaceutical companies and pharmaceutical shops that are violating the law by manufacturing and selling diclofenac for veterinary use is urgently needed if we are to save vultures from extinction.
Even if the government ban is fully implemented, it will take many years for the vulture population to recover. Vultures breed slowly and take five years to reach adulthood. When any large population crashes, as the vultures have, the amount of genetic diversity in the population also is likely to dwindle. This is a concern because a population's genetic diversity reflects its ability to adapt to environmental challenges such as changing climate or outbreak of disease. Without the ability to adapt, populations and whole species may become extinct. The government needs to develop an up to date action plan to conserve the species.
With support from the RSPB, UK the newly-formed consortium Saving Asia's Vultures from Extinction (SAVE) (www.save-vultures.org) manages three conservation breeding centres in India where 271 vultures are housed and successful breeding of all three species has now occurred. There are also conservation breeding centres linked to the SAVE programme in Nepal and Pakistan with the help of WWF. Adding wild birds to the captive colonies, located in Pakistan and India, is crucial, but political and logistical barriers are hampering efforts. The aim should be to raise awareness of the problem and to increase political will in Bangladesh to get this matter resolved.
A turning point has hopefully now been reached in the race to save these birds from extinction. We need to create local conservation groups to lobby governments and raise awareness in Bangladesh, to make sure the diclofenac bans are effective in time to prevent total extinction so that in 10 or 15 years' time, we can re-introduce the captive birds to a safer world. Until diclofenac stops being used for cattle in Bangladesh these birds need to be bred in captivity, to be released only when it is safe for them in the wild once more. We need also to support our conservation partners, showing farmers that there are alternative drugs to diclofenac that are just as effective in treating cattle.
There is still a lot more to do to prevent equally dangerous human diclofenac formulations as well as other untested veterinary drugs, being used in its place. The effect of this drug on birds of prey remind us of the devastating impact of the pesticide DDT on birds worldwide. It took years for governments to remove DDT from use. Diclofenac is so devastating that we do not have many years if our threatened vultures are to be saved. Removing diclofenac from veterinary practice and constructing more captive breeding centres are the only ways to save these birds which play such an important role in the environment.

Dr Md Lutfor Rahman is a research ornithologist, International Wildlife Consultants Ltd, Carmarthen, Wales, UK. E-mail: [email protected]

Chris Bowden is International Species Recovery Officer & SAVE Programme Manager, Royal Society for the Protection of Birds (RSPB), The Lodge, Sandy, UK. E-mail: [email protected]