Long-billed vulture population drops 73% in past nine years, says BNHS study
The significant reduction in vulture population over the years is due to the widespread use of a veterinary drug that has diclofenacmumbai Updated: Dec 22, 2017 17:31 IST
While there has been a drastic decline in the population of long-billed vultures between 2007 and 2015 in India, the population of Oriental White-backed Vulture appears to have stabilised after years of decline, says a paper published on Wednesday in the journal ‘Bird Conservation International’.
Along with the slender-bill vultures, India’s three resident species of Gyps vultures, which numbered in millions, are now critically endangered.
The study, based on nation-wide surveys carried out in different parts of India in 2015 by Bombay Natural History Society (BNHS) was supported by Royal Society for Protection of Birds (RSPB), United Kingdom. “A more robust method was used in 2015 than in 2007 to recalculate the population size,” said Vibhu Prakash, deputy director and head of the BNHS-Vulture Conservation Breeding Programme, and lead author of the paper.
“In 2007, estimates of the population size for each species were 11,000 for Oriental white-backed vultures, 45,000 for long-billed vultures and 1,000 for slender-bill vultures. In 2012, the survey findings were encouraging as they reported a slowdown in the decline for all three species and the possible first sign of recovery in the Oriental white-backed vulture. In 2015, estimates were approximately 6,000 for Oriental white-backed vultures, 12,000 long-billed vultures and 1,000 slender-billed vultures which are alarmingly low,” read the paper titled, ‘Recent changes in populations of Critically Endangered Gyps vultures in India.
“The good news is that the positive trend for Oriental white-backed vulture population appears to be continuing. The bad news is that the long-billed vulture population continues to decline. For the rarest of the three species, the slender-billed vulture, numbers counted are now too small to estimate a reliable trend,” said Prakash.
The significant reduction in vulture population over the years is due to the widespread use of a veterinary drug that has diclofenac, a pain relief also used in human medicine, was found to be extremely toxic to vultures that fed on carcasses of animals that were given the drug. “Diclofenac is only one of over a dozen drugs known as non-steroidal anti-inflammatory drugs (NSAIDs) available in India. Four other NSAIDs — aceclofenac, carprofen, flunixin, ketoprofen — are toxic to vultures, none of which are banned, and another drug, nimesulide, is probably toxic too,” he said.
Every four years, surveys to count vultures are repeated by BNHS covering approximately 15,500 km roads among 154 road transects and 13 states in the country.
“The paper is reminder of the vulture crisis in India which is far from over and more regulatory actions on vulture-toxic NSAIDs are required to save vultures from extinction,” said Deepak Apte, director, BNHS.