CHENNAI: The vulture population in Tamil Nadu is estimated to have come down to only about 350, according to a recent survey by Arulagam, a non-profit nature conservation organisation.
The once omnipresent birds have declined drastically in numbers — by about 99 per cent since the 90s. Their number has stagnated around 300 over the last few years.
Across India, the vulture population has been estimated to have declined from over 40 million in 1999 to a mere 20,000 now by the Bombay Natural History Society (BNHS). The trend has been similar in Tamil Nadu. “We’re estimating a maximum of 350 to 400 birds in the State, of which two thirds are white back vultures,” said S Bharathidasan, one of the founders of Arulagam. There are three other species found in the State — long-billed vulture, red-headed vulture and Egyptian vulture. However, these species are categorised as critically endangered, according to BHNS. “We’ve barely sighted a dozen birds from the three critically endangered species,” he said.
Vulture population is mostly concentrated around Mudumalai, Moyar and Sathyamangalam forests. Egyptian vultures alone are spotted in regions around Dharmapuri and even on the outskirts of Chennai. Bharathidasan claims that the numbers have not been very promising.
Across the rest of the country too, vultures that were spotted as commonly as crows are facing a serious threat of extinction. There is a 97-99 per cent decline of population of several species of vultures in India, according to a study published by Vibhu Prakash of BNHS.
“This is the fastest decline of any species in the world. It’s alarming,” said Asad Rahmani, former director of BNHS. “When I was a child, I used to walk fast on Lodhi Road (in Delhi) to avoid vulture droppings. Those birds excreted everywhere,” he said adding that he never thought there would come a day, when he’d struggle to even spot them.
Drugs biggest killers?
What went so dramatically wrong with these birds?
The population of vultures has dropped for a variety of reasons including habitat fragmentation, poaching and epidemics. Decline in grazing is also cited as a major reason. While these reasons can be cited for the decline of any species’ population, they have failed to explain the rapid decline.
After several failed hypotheses, an international team of scientists under the aegis of the Peregrin Fund, found that the decline was associated with diclofenac, a non-steroidal anti-inflammatory drug (NSAID) administered to cattle as a pain-killer. Vultures that feed on carcasses of animals recently treated with drug suffered renal failure that caused visceral gout and death eventually. The drug which was initially conceived to treat humans, later went on to be used predominantly only for livestock. It is a fast-acting, effective painkiller costing about `20. “It’s unfortunate that the drug is lethal primarily to vultures and only a few other species,” said Rahmani.
Vultures with long neck designed for scavenging did the stigmatised job of getting rid of rotting carcasses. The birds, therefore, were never seen in positive light and the need to conserve the species was not given enough importance.
The vital role that these birds played in the ecosystem was overlooked. Vultures, which facilitate speedy disposal of rotting diseased animals, are immune to the pathogens themselves owing to the high acidity of their stomachs. Unlike rodents or dogs, vultures did not transmit diseases from their prey.
“In Rajasthan, for example, it was found that the declining vulture population was related to increase in leopard-human conflict,” said Environment Monitoring and Action Initiating founder T Murugavel.
The declining vulture population, he explained, has led to availability of more surplus meat from butcher shop, and made dead animals available for dogs, thus increasing dog population. With growing population of stray dogs, more of them wandered closer to forests thus luring leopards which had a taste of these easy targets and came to villages to hunt dogs, thus increasing a conflict with humans.
However, the situation is not all black, and there has been a slight growth in vulture population in recent years, according to a recent study by Cambridge. This can be attributed to the ban on diclofenac in India, Nepal and Pakistan. Despite drug companies contesting this decision, the Madras High Court upheld the ban. In its judgment, it said, “Vultures are universally accepted as ‘natural sanitary workers’, absolutely essential for environmental and ecological balance.” However, other drugs such as aceclofenac, carprofen, flunixin, and ketoprofentoxic, which are detrimental to vultures, are still in use.
The measures to arrest the decline include establishment of more safe zones, captive breeding, protecting breeding sites and sensible eco-tourism, suggests Murugavel.But an increase in vulture population would not happen very fast as the birds breed only once a year, said Bharathidasan. “Even after hatching, the chics stay in the nest for a few months making them hard to count,” he said, adding that the birds are becoming more elusive.
Numbers don’t lie
A survey published in 1999 by BNHS across 18 protected areas in India estimated that in 1991-92, there were over 40 million vultures in India. However, between 1992 and 2007, the population of two of the three Indian vulture species of the genus ‘Gyps’ — the long-billed Gyps indicus and the slender-billed G tenuirostris — crashed by an astounding 97 percent and the population of the third species - white-rumped G. Bengalensis - plummeted by 99.9 per cent
From millions, the population of the three Gyps species has come down to about 20,000 - 12,000 long-billed species, 6,000 white-rumped species and the rarest slender-billed vultures at 1,000
The IUCN has declared that all these three belong to the highest risk category of critically endangered species
Due to the decline in numbers of vultures, the Parsi community is finding it difficult to sustain their unique funeral ritual, where they dispose of the dead in ‘Towers of Silence’ to be consumed by scavenging birds