Once described as possibly the most abundant large bird of prey in the world, the Critically Endangered White-rumped Vulture (Gyps bengalensis) has suffered a population decline of more than 99.9% in just 15 years. According to The IUCN Red List of Threatened Species™, 10 of the world’s 23 vulture species are threatened with extinction, with the most rapid declines occurring in Asia. As scavengers, vultures have an important ecological role and these population declines have serious consequences for humans and the environment.
Between 1992 and 2007, a large-scale decline in vulture numbers was observed across Asia and the White-rumped Vulture was not the only victim. Two other species, the Indian Vulture (Gyps indicus) and the Slender-billed Vulture (Gyps tenuirostris), both Critically Endangered, suffered a 97% decline in population numbers. These declines have been directly attributed to the veterinary use of the non-steroidal anti-inflammatory drug diclofenac, ingested by vultures that ate carcasses of cattle that had recently been treated with the drug.
Diclofenac causes renal failure and death for vultures. Due to the strength of the drug and the tendency of vultures to feed in large groups, research has shown that just one in 760 livestock carcasses needs to contain diclofenac to cause the population decline that has been observed. Despite a manufacturing ban in Pakistan, Nepal and India and a ban on its sale and veterinary use in India, there are concerns that this drug is still affecting vulture populations in Asia.
“The dramatic decline of vultures in South Asia highlights that we can never be complacent about conservation, even when it comes to ‘common’ species”, said Dr Scott Perkin, Head of IUCN’s Biodiversity Conservation Programme, Asia. “The fortunes of a particular species, or even an entire group of species, can change for the worse in a remarkably short period of time. Fortunately, in this case, a combination of vigilance, strong science, political commitment and the dedicated efforts of local and international organizations, including many IUCN Members, means that there is still hope that vultures may one day return to the skies of Asia.”
Despite their mixed reputation vultures provide vital ecosystem services. Their most important role is removing carcasses of animals that would otherwise be left to rot. This waste removal service reduces the possibility of a carcass becoming a hazard to human health and controls the populations of disease-carrying scavengers such as feral dogs and rats. In India, the decline of vultures has seen an increase in the numbers of feral dogs and with it, presumably a higher incidence of dog bites and rabies than if the vultures were still there.
The loss of vultures is also having a social and cultural impact in South Asia. An ancient custom known as sky burial, where the human dead are left in ‘towers of silence’ or on stone pillars at the tops of hills for vultures and other scavengers, is practised by the Zoroastrian-Parsi community in India and Pakistan and by Tibetan Buddhists, but the tradition is now being negatively impacted by the decline in vultures.
However, there is a solution. In addition to calling for an end to the use of diclofenac and its sale in multi-dose vials, IUCN is working with the Governments of South Asia and a consortium of organizations known as ‘SAVE’ (Saving Asia’s Vultures from Extinction), which is also supported by SOS – Save Our Species, to establish 100 kilometer radius ‘Vulture Safe Zones’ clear of diclofenac and other potentially dangerous veterinary painkillers. This involves awareness work at all levels, from Government officials, vets and local farmers. Once carcasses have tested negative to the drugs and an area is declared safe, birds from one of the region’s conservation breeding programmes, which have now successfully bred all three Gyps species, can potentially be released into the area in the future.
“Thankfully, there is at least one safe alternative drug available to the vets, which is already being made by more than 40 different companies in South Asia,” said Chris Bowden, the SAVE Programme Manager and Co-Chair of the IUCN SSC Vulture Specialist Group. “If this is fully adopted for veterinary practice, then there will be a real prospect for releasing the captive birds back to a safe environment and a recovery of Asian vulture populations.”
A workshop involving senior Government representatives and scientists from Bangladesh, India, Nepal and Pakistan as well as international experts and community leaders will be held in Delhi in early May 2012. Amongst other items, the workshop will consider the latest vulture population trends in South Asia and emerging conservation issues. It is hoped that the workshop will lead to a regional declaration on vulture conservation and that it will also catalyze enhanced collaboration among the range states, including the development of a regional vulture project.
For more information, please see www.save-vultures.org