A veterinary drug and a breeding programme are raising hopes for a revival of the endangered scavenger
An Indian vulture (Gyps indicus), listed as Critically Endangered since 2002 (Photo: Alamy)
THE KEOLADEO National Park is a vast bird sanctuary that lies just a couple of kilometres away from the city of Bharatpur in Rajasthan. It was formerly a hunting ground for the maharajas there, a tradition that, it is said, dates back to 1850, when the royals descended upon the grounds, sometimes in the company of the viceroy, to shoot birds. A protected site today, its woods and man-made wetlands are home to around 350 species of migratory and resident birds. In the winter, the numbers of birds swell to thousands, and it is around this time especially that scores of ornithologists descend upon the park with binoculars to study and research, and sometimes, just to gaze with pleasure, at the park’s many avian residents.
Vibhu Prakash Mathur was one of them. A researcher with the wildlife research organisation, Bombay Natural History Society (BNHS), and today its deputy director, Prakash spent a lot of his time in the 1980s studying raptors, or birds of prey, at the park. He would survey their numbers as part of a project on the ecology and status of raptors in India, counting both adult birds and little hatchlings in their nests. He left for Mumbai in 1989 and returned about seven years later. There was a shock in store for him.
Although vultures are large birds, their carcasses often go unnoticed. They usually die on large trees or in secluded areas, either entangled in tree branches or the thickets below, with jackals often feeding on them. But now, he began to notice many dead vultures, their carcasses in nests, trees or on the ground below them. He would see them dozing in trees, their long necks slumping down gradually until their beaks hit a branch, and they woke up with a startle. This would go on for many days, after which they would just fall to the ground, and be dead within minutes.
When there has been an abundance of any species of animals or birds, Mathur explains, a decline, however rapid or sudden, is never quite evident. Even though to Mathur’s eyes the numbers appeared to have declined, and he encountered dead vultures frequently and even found carcasses of cattle without any or very few vultures feeding on them, this time he began to survey just the park’s vulture population. The results were startling even to him. Three Gyps vulture species, which count among the most abundant vulture species in the park and the rest of the country, had seen a dramatic decline—by 97 per cent in long-billed vultures and 96 per cent in white-rumped vultures—all in a matter of just about a decade.
But it wasn’t just the park whose vulture populations were suddenly going through a decline. As Mathur and other researchers found out, the population of vultures across India and the rest of South Asia had undergone a dramatic and sudden collapse. We now know that the population size of the three Gyps species had declined between 96.8 per cent (for the long-billed vulture) and 99.9 per cent (for the white-rumped vulture). Along with the red-headed vulture species (also known as king vulture), the four had entered the “Critically Endangered” list. These findings came as a shock globally. It was among the most rapid declines witnessed in an animal or bird species population in recent times. And for some time, it was also unexplained.
Various theories for such a crash were proposed, from food shortages, habitat loss, the use of pesticides in agriculture to an outbreak of disease, perhaps malaria, calcium deficiency, and even being mowed down by trains, as they feasted on carcasses on tracks. When the dead birds were opened up for post-mortem, Mathur recalls, they would find chalky white deposits on the birds’ organs, evidence of visceral gout.
When it was found that a non-steroidal anti-inflammatory drug (NSAID) called Diclofenac—used to treat cattle in India since the 1980s—was the real culprit, even that was met with scepticism. “Just 5 per cent of the cattle in India is believed to get treatment. Could consuming the flesh of such a small number [that might have been treated with Diclofenac] lead to such a crash?” Mathur recalls many asking. When the BNHS team consulted Cambridge professor Rhys Green to understand what quantities of Diclofenac-laced carcasses could cause the kind of population drop in vultures that India had just witnessed, he estimated it would require less than 1 per cent. “We sampled carcasses from across the country and found more than 11 per cent had Diclofenac,” he says.
A decline in vulture populations has already had a corollary impact, from a rise in feral dogs (and dog attacks on humans) to the small community of Parsis in India finding the flesh of their dead, laid down for sky burials in their Towers of Silence, unconsumed. Something drastic had to be done if these four vulture species in India, already on the verge of extinction, were to not disappear in just a few more years. First of all, vultures may be a wild species, but they now needed to be bred and reared. And second, since Diclofenac continued to be used, even though its veterinary use was banned in 2006, an alternative drug had to be identified.
After years of such a search—apart from Meloxicam, which was identified as being safe for vultures in 2006 but has failed to attract much interest—researchers have mostly drawn a blank. A few weeks ago, however, a team of scientists from the Indian Veterinary Research Institute (IVRI) and researchers from BNHS found that Tolfenamic acid, another NSAID, is safe for vultures. Administering it first to some Himalayan griffon vultures caught in the wild—and only after they continued to survive, testing it upon the critically endangered white-rumped and long-billed vultures bred in captivity—the researchers found that Tolfenamic acid was harmless to vultures.
“This is really promising,” says Mathur. “Because it works as well as Diclofenac for cattle. And if we can push its use now, we can make the environment safe for vultures again.”
FIFTEEN YEARS since Diclofenac was banned for veterinary use, its use may have fallen, but it is still around. Since it was available for human use, veterinarians and cattle owners continued to use bottles meant for human use on cattle. In 2015, the Government tried to deal with this by restricting the vial sizes of Diclofenac to three millimetres. But this too, according to researchers, has helped only partially, making the discovery of a credible alternative crucial.
The identification of Meloxicam in 2006 was greeted with much enthusiasm, but 15 years since, its use hasn’t caught on in India. “Meloxicam has been fully accepted by many veterinarians [including across Europe], but every NSAID has slightly different properties, and vets tell us that Meloxicam works well and is effective for longer than some of the alternative drugs. But it doesn’t act as quickly after the initial injection and it doesn’t have the anti-pyretic properties [reducing fever] that others do,” says Chris Bowden, programme manager at SAVE (Saving Asia’s Vultures from Extinction), a consortium of international organisations. “In addition, some formulations [especially some produced in India early on] were highly alkaline and less effective, which unfortunately may have put some vets off. In fact, we took steps to contact many of the major manufacturers to point this out, and many formulations are now far better and more effective.”
Tolfenamic acid is being greeted with a lot of expectation because it is already produced by a number of Indian manufacturers and is similarly priced to other drugs in this category. Mathur points out that with Diclofenac’s vial sizes being restricted to three millimetres, trying to acquire enough doses to use for cattle now works out far more expensive than a drug like Tolfenamic acid. “Vets often complain that they want choices, as each NSAID has slightly different properties. The fact that we now have two drugs, instead of one, is already very good news,” Bowden says. “But interestingly, Tolfenamic acid does have anti-pyretic properties and there are early signs it is already being taken up strongly in Bangladesh where Ketoprofen [another NSAID found to be dangerous for vultures] was banned in February 2021, and so taking its place, whilst Meloxicam remains at stable levels of use and is popular too.”
But while Diclofenac is banned, many of its replacements currently in the market (such as aceclofenac, ketoprofen, flunixin and nimesulide) have been found to be equally toxic to vultures. Many organisations, such as SAVE, are campaigning for these drugs to be banned too. “India led the way back in 2006, taking the bold step to ban veterinary Diclofenac, which others followed. But now India needs to be far more proactive to avoid these other veterinary drugs undoing that early progress and leading to the final demise of vultures in India,” Bowden says.
In November 2020, the Union Government unveiled its Action Plan for Vulture Conservation in India 2020-25, which puts out an ambitious conservation strategy, from the establishment of breeding centres to stricter audits on the sale and use of NSAIDs like Diclofenac and vulture-safety trials for several Diclofenac-like drugs. “If the Government implements it strictly and puts in more money for vulture conservation, that is what is strictly needed,” Mathur says. According to him, vulture safety trials on five more NSAIDs will commence soon. If more vulture-safe drugs are found, and bans against those unsafe are strictly enforced, the skies could once again be made safe for vultures to return.
In October last year, the doors of an aviary at Pinjore in Haryana were flung open. And eight white-rumped vultures—the whites of their neck ruff, rump and underwing so distinctive from the rest of the dark plumage—stepped out cautiously. Some of them perched on nearby trees and mingled with their wild cousins, and the others hung around near the aviary and returned to them. It took between 48 hours and a month for the eight to finally take flight, much to the delight of Mathur, and leave the centre that had been their home for all their lives. Similar releases have been undertaken since, in another breeding centre run by BNHS in West Bengal’s Buxa Tiger Reserve. Just an estimated 8,600 of these vultures remain, 6,000 of them in India.
Preparations to breed vultures first began in 2004, when BNHS converted the vulture care centre it ran into a breeding centre for vultures instead. Since then, they have established and now run three more centres (in Assam, West Bengal and Madhya Pradesh) while also helping the Central Zoo Authority to run similar facilities elsewhere in the country. While the centres focus their efforts on the three critically endangered vulture species—the slender-billed, the white-rumped and the long-billed—they have begun to make preparations to breed the red-headed vulture, the fourth vulture species to enter the list.
Breeding vultures is a cumbersome task. They usually come of breeding age (depending upon the species) when they turn five years old, and they lay only one egg every year. To give their effort—and their species—a boost, Mathur and his colleagues have begun to trick the vultures into laying more than a single egg per year. “If an egg gets lost, vultures usually land up laying another egg within a month. So, we take the first egg, hatch it ourselves in the incubator and take care of it for another 10 days or so, and then swap it with the vulture’s second egg,” Mathur says, explaining how the first egg is raised by its parents at the centre, while the second is reared in nursery aviaries.
THE BREEDING programme may have begun slowly, a process Mathur describes as hatching eggs one at a time, from obtaining permissions to starting the programme, acquiring the birds, and then opening other centres, and watching vultures lay and hatch their eggs one at a time. But over 15 years since the programme began, it has reached the point—with the four centres now being occupied by around 780 critically endangered vultures—where it now wants to put in motion its other part: releasing the birds into the wild.
Releasing the vultures is fraught with risk because the environment isn’t entirely safe, with Diclofenac and its other toxic siblings still lurking around. But it is a chance Mathur appears willing to take cautiously. BNHS plans to release a few birds every year, monitoring them through the satellite transmitters and wing tags that have been fitted onto them. If all goes well, they plan to release 100 pairs of each of the three birds annually at some point.
To make them fit to live in the wild, while rearing them in captivity, the teams at these centres ensure there is little human interaction. They also put out meat at these aviaries to attract wild vultures frequently, so that those being raised can intermingle with their wild counterparts.
Some fatalities among the birds released, Mathur says, are to be expected. Of the 10 released at the Buxa Tiger Reserve, all continue to do well. Of the eight released at Pinjore, however, three are believed to have died. One got electrocuted after dashing into a power line. Two others which had joined a group of Himalayan griffon vultures (which can exist at high regions of the Himalayas) perished as they flew to higher altitudes. “No bird has been poisoned, however, by Diclofenac,” Mathur says.
The remaining birds, however, continue to survive, hovering within a 100-km radius of the two centres, and three of them have even begun breeding. Tracking these birds, occasionally, Mathur and his team will even put out meat when they notice the vultures are hungry.
Does he feel a bit emotional when he tracks these birds, considering he has raised them at the centres? “Oh no,” he says. “It’s a strict policy to not have any emotional attachments at the centre. Otherwise, the vultures can become parasites, always coming to you when they are hungry. But having almost hand-reared them, seeing them grow from a ball of cotton to such menacing-looking creatures, there is always a heartbreak when you hear one of them has died.”