The second most famous vulture in the lore of the Hindu epics is Sampati. We run into him midway through the Ramayana, after the demon king Ravana has made off with Lord Rama’s wife Sita, and when Rama has sent a search party down the spine of peninsular India. The searchers, discovering no trace of Sita anywhere, decide they’d rather starve to death than return in failure, so they settle down in a cave to waste away. Drawn by the prospect of an easy meal, Sampati arrives. He is aged and wingless, but he can still watch, with the plentiful patience of his species, as living bodies turn into carcasses. In principle, vultures have the surest source of food on the planet, because death is inevitable. To find it, all they have to do is look for life and wait.

But then the searchers tell Sampati about their quest, and about Rama’s grief, and Sampati realises he has seen what they seek. With his astute vision, he has spotted Ravana in a celestial chariot, carrying Sita across the southern sea to Lanka. And so he tells them about it, even though, in doing so, he is giving them a reason to live again. The nature of Sampati’s heroism lies here: not just in an old bird sacrificing food, but in a vulture acting against its most elemental instinct. Vultures appear in such neat lockstep with death that they seem to practically usher it in. Sampati has done the opposite. He has prolonged life. He has driven death away.

The Ramayana doesn’t describe Sampati at length, but since he resided in a cave, we might presume that he was a long-billed vulture, a Gyps indicus. Ranging over central India, the long-billed vulture nests not in trees but on the crags and ledges of rocky cliffs. The cliffs grow so stained with their droppings that, in 1867, the British ornithologist Allan Octavian Hume had a hard time climbing a hill in Rajasthan in search of a long-billed vulture’s nest. Having removed his boots, the reason for which he left unexplained, he ‘crept to the lowest ledge, a work of extreme difficulty, owing to the excessive slipperiness of the white crusted rocks.’ Hume measured the vultures whenever he could and jotted down their dimensions in his scrapbook. The long-billed is not a massive bird. Its wings rarely span more than two metres, and even the plumpest specimens weigh only about five or six kilograms, half the heft of American condors. Its covert feathers – the feathers on the surface of its torso – are a pale buff, but the feathers just beneath are darker. Its head is bare and coloured like wet sand, but its throat has a smattering of thin down, and around its neck, it wears a ruff of soft white feathers. Standing near a carcass, the long-billed vulture looks like a morose undertaker who has doffed his hat but refuses to take off his two-tone overcoat.

Even the doyens of India’s vulture community sometimes have a tricky time telling the long-billed vulture apart from its two cousins: the slender-billed, which nests in solitary pairs in trees just south of the Himalayas, and which for decades was mistaken for the long-billed; and the white-rumped, which lives in tight colonies distributed through small groves of ficus or arjuna trees. Together, these species once prevailed in thick abundance in India, a country that provided generous feasts of wildlife and livestock carcasses. No nationwide census was ever taken, but the accepted figure among experts seems to be that there were once 40 million vultures in India. When Vibhu Prakash, a raptor scientist, was working at the Keoladeo National Park in Rajasthan in the 1980s, he’d see vultures lifting into the air at around nine o’clock in the morning, just when the day was heating up. ‘We’d watch them disappearing very high in the sky, soaring on one thermal and then another with great speed, and we’d try to estimate how fast they were going,’ he said. When an especially big flock flew by, the land darkened as if a raincloud had passed overhead.

India’s vultures scout for food by eyesight alone – eyesight so fierce that, for a long time, ornithologists assumed that the birds must have a powerful sense of smell as well. One British army lieutenant, in 1833, killed a dog, wrapped its body in canvas and stuffed it up a tree. Over the next few days, he saw vultures perch directly above the parcel and concluded they must have been attracted by the odour of putrefaction. He skimmed too lightly over the detail that vultures had been roosting on that particular tree even before he’d lodged his dog into its branches, or that the ability to smell out a dead dog from a few feet away was no indication that the birds could pick up the scent of carrion from lofty heights. ‘When they actually descended on a carcass,’ Vibhu Prakash said, ‘it was like an airplane cutting through the air: whooooosh! Suddenly they were all around you.’ Vultures in mid-feed take the most perfect collective noun: a wake. In sufficient numbers, a wake of vultures can make very short work of a carcass. Skin a cow and throw it into the open, Prakash said, and it will have been divested of its flesh within half an hour.

In South Asia, a land of many devoutly followed faiths, a bird so closely associated with carcasses inevitably becomes entangled in the cultural practice of death itself. Every religion is, after all, a fixation with the notion of death – a way to come to terms with the truth that life always ends. Buddhists in Tibet follow a ritual of sky burial, in which a corpse is formally deposited in a sacred area, to be consumed by vultures and other carrion birds; the Zoroastrians, who migrated from Iran to India more than a millennium ago, have a similar custom. In Hinduism, the venerated cow is never eaten; even the skinning of dead cattle is regarded as necessary but unholy work, to be foisted upon an oppressed lower caste. Until not very long ago in rural India, the cow’s remains, once flayed, were tipped into a dump outside the village where vultures had their fill. By sustaining themselves on corpses the vultures were almost reanimating them, using their dead flesh to produce new, young birds. It was a strange, elegant version of an afterlife.

The vultures were here first, of course – present in this part of the world a few million years before any glimmer of human faith came into being. Relatively speaking, we’re transients to them. It wasn’t that we were folding them into our culture; rather, the vultures were accommodating our whimsical religious habits into their old ways of feeding. And they might have outlived our species handily, had we not been so skilled at poisoning our planet. For, in the 1990s, scientists noticed a bewildering and alarming decline in the population of vultures across India. From the bygone 40 million, the numbers dropped to around 10,000 in 2013 – an annihilation, by any measure. It feels like a doubled extinction. The death of the vulture is also the death of how we cope with death itself.

This isn’t a mystery story – or at least, not any more. In 2003, scientists working across Britain and India found that the culprit behind the great vulture die-off was not a pathogen but a man-made drug. Diclofenac, a chemical patented in 1965 by a Swiss pharmaceutical company, began to be used widely in arthritis medication in the late 1980s. It eased stiff joints and reduced inflammation; even non-arthritic patients could use it to relieve the pain of a toothache or a migraine. After the patent expired, diclofenac became cheap: in India, just a few cents per tablet. It was made up into a veterinary product as well, so that farmers could buy it for cows or buffaloes suffering from some wound or illness. With diclofenac, the animals could be kept out of pain for a few more weeks of milking or perhaps even to birth calves – valuable revenue for the Indian farmer – before they died and were carted to the dump. But when vultures fed on these carcasses, the diclofenac residues damaged their kidneys and gave them visceral gout; chalky clots of uric acid built up in their organs, eventually killing them. In this too, diclofenac was astoundingly effective. If we’d set out deliberately to wipe the country clean of vultures, we couldn’t have done any better.

The cull of Indian vultures happened just when we were realising, with fresh urgency, that we had to repair a number of other ruptures in the natural order that we’d perpetrated. The smoke in our skies, which warmed the earth; the plastic in our oceans, which killed the fish; the terraforming of our jungles, which evicted their wildlife. When the vultures died off, they stopped eating the bodies of Zoroastrians and Tibetan Buddhists, and of farmed cattle. Their extinction, and their sudden absence from our lives and our deaths, marked the severance of yet another human tie with nature.

In 2006, the Indian government outlawed diclofenac for veterinary use. It helped that there was another drug on the market, called meloxicam, that was just as cheap and effective as diclofenac, and that wasn’t toxic for vultures, said Chris Bowden. Bowden is the programme manager of SAVE – Saving Asia’s Vultures from Extinction – an alliance that includes the Royal Society for the Protection of Birds as well as the Bombay Natural History Society. Since 2004, he has spent most of his time in India. When I spoke to him on Skype this past May, he was in his apartment in Bengaluru, wearing a T-shirt with the caption: untouched paradise. A summer storm grumbled outside his window.

For SAVE, lobbying the government to ban diclofenac was, in relative terms, a straightforward process. Building India’s vulture population back into even a fraction of its former strength has been another matter altogether. ‘The problem was, no one had bred Indian vultures in captivity before,’ Bowden said. ‘It was just unknown. And so, back in the mid-2000s, we had a lot of people who were very sceptical, and thought that we didn’t know what we were doing.’ From the absolute shallows a decade or so ago, numbers in the wild have staggered back up to around 30,000 today. And in SAVE’s four breeding centres, ‘we have so many vultures in there that we don’t know what to do with them,’ Bowden said. ‘Now we’re dying to send some of them back into the wild.’

The first few months of 2020 were a torrid time for SAVE’s breeding centres. The four facilities are spread across India’s northern half: one in the state of Haryana, not far from Delhi; one in the state of Madhya Pradesh, in India’s solar plexus; and two in the eastern states of Assam and West Bengal. During the Covid-19 pandemic, every centre found itself in a red zone – a coronavirus hotspot that was strictly battened down. Travel was practically out of the question, and boundaries between districts were sealed.

In the breeding centre in Haryana, near the town of Pinjore, Vibhu Prakash needs a hundred goats a day to feed his 360 vultures. Ordinarily, Prakash buys old, infirm goats, since vultures prefer lean meat to fatty meat. But his usual markets were shut, and the only goats he managed to find during the pandemic had been plumped up on farms. Still, they had to suffice. To source even these goats with any regularity, Prakash and his colleagues had to work until they wilted. ‘Our supplier went out to get them from Rajasthan or other states,’ he said. ‘Then the cops wouldn’t let him travel, so we had to get him passes from the government.’

In late May, even as the pandemic burned on, a cyclone hit West Bengal, flattening electricity and telephone lines. The breeding centre in Rajabhat Khawa, located in a wildlife park near the border with Bhutan, lost power. In addition to figuring out meals for its vultures, the staff had to find diesel for their generators – not just to switch on the lights and charge the mobile phones, but also to electrify the fence that keeps the park’s elephants out.

Of the four, the Pinjore centre is the oldest. It was founded in 2001, as a partnership between the Royal Society for the Protection of Birds, the Bombay Natural History Society and the state government. Formally, it is called the Jatayu Conservation Breeding Centre – another throwback to the Ramayana. Jatayu, the most renowned vulture in Hindu mythology, is Sampati’s younger brother, and his heroism ends in spectacular tragedy. When Ravana first kidnaps Sita, Jatayu flies to her rescue and attacks the demon king’s chariot. In a mid-air battle, Ravana slices off Jatayu’s wings, and the grand bird plummets to his death. Far south of Pinjore, on a rocky hilltop in the state of Kerala, a sculptor has built a colossal concrete statue of Jatayu where he is said to have fallen to Earth. The statue is ludicrously literal but also strangely moving. Its head might resemble the logo of a fried-chicken chain, but one side of its body has been sheared off. Its remaining wing unfurls to the side, and its sole talon claws the air. Jatayu isn’t dead yet, but he is already helpless and beyond preservation.

Given the end of Jatayu, calling the Pinjore centre after the slain bird sounds like an odd move, but perhaps the name serves as an ever-present reminder of a fate to be avoided. The first of the aviaries in Pinjore was built in 2004, to designs drawn up by Jemima Parry-Jones, a raptor breeder who directs the International Centre for Birds of Prey in Gloucestershire. Parry-Jones has bred more raptors in captivity than most of us could name: African pygmy falcons, Indian tawny eagles, secretary birds, American black vultures, Aplomado falcons. ‘The nice thing about vultures is that most of them are colony nesters,’ Parry-Jones said. ‘So rather than building one aviary for every pair of birds, you can build one for every fifteen pairs.’ From the outside, the aviaries look like warehouses: a hundred feet long, forty feet wide and twenty feet high. The cement walls are broken up by large ‘windows’, sections of longitudinal bamboo staves that let the air in. The vultures sit on ledges and perches embedded into the walls, below a roof made of strong metal mesh – ‘You know,’ Parry-Jones said, ‘in case leopards or monkeys get on top.’ Every aviary has four baths that are replenished twice a week. Whole, skinned goat carcasses are slid in through a door. ‘The aviaries are long enough that the birds can fly from one end to the other for exercise, to keep their physical fitness up.’ At one point, the breeders experimented with putting individual pairs of vultures in smaller aviaries. The birds lost muscle tone, and their hearts weakened. ‘We had to work all these protocols out,’ Parry-Jones said.

The first tenants of these aviaries were young vultures taken from nests, before they fledged. Vulture-gatherers shinned down cliff faces, or up trees, to collect them. ‘The local villagers never wanted us to take the chicks away,’ Parry-Jones remembered. ‘We had to explain that these birds probably wouldn’t survive anyway, because of the diclofenac out there.’ In Pinjore, Parry-Jones and Prakash worked up a system: taking the first clutch of eggs away from parents, incubating them, and returning the chicks when they were six to twelve days old; then hatching the next clutch of eggs and rearing those birds to an adult size over four months, before moving them to the aviaries. Elsewhere, methods had to vary; at Rajabhat Khawa, for instance, the frailty of the electricity supply means that artificial incubation is difficult. ‘So there, the mum and dad vultures do all the work,’ Parry-Jones said. Of the 700-odd birds in the four centres today, more than half have been born and reared in captivity.

They live in such close proximity, these humans and the birds they raise, and yet they rarely see each other in the flesh. At Pinjore, Prakash watches the vultures through closed-circuit cameras installed in every aviary. Vultures are jittery creatures. They tolerate the staff who slip discreetly and efficiently into the aviaries every two or three weeks to clean up. But if an unfamiliar person – or, for that matter, any other potential threat – approaches suddenly, a vulture will throw up the stinking contents of its gut. It’s an ancient reflex; the foul smell puts the predator off, and meanwhile the bird has become lighter, so that it can get away at speed. If Prakash spent plenty of time with his vultures, they’d get too accustomed to him. ‘They could easily become like pets. They’d feed from your hand,’ he said. ‘But then they become useless for conservation, because they won’t go back out and mingle with their own kind. So we avoid it. We want minimum human contact with them. Because ultimately, we want them to go back into the wild.’

Of the twenty-three species of vultures around the world, sixteen are facing some startling level of endangerment. In Spain, a slide in vulture populations has been traced back to the old enemy, diclofenac; in Portugal, after the passage of a law requiring farmers to burn or bury the carcasses of livestock, vultures became a rare sight in the skies; in Botswana, Kenya and South Africa, the poisons used by poachers to fell elephants or by farmers to deter predators like jackals have fatally sneaked into the bloodstreams of vultures. And since every kind of vulture is a keystone species, critical to the survival of entire ecosystems, it means that every ecosystem is in trouble. In nature’s scheme of things, the role occupied by vultures is a vital one – so vital, in fact, that they’ve evolved into being twice, in two separate and independent ways. The Old World vultures in Europe, Asia and Africa have different ancestors altogether from the New World vultures of the Americas – a phenomenon known as convergent evolution. It’s as if natural selection kept finding that the best way to deploy long-range scavengers was to make a particular kind of bird. A bird with a bald head, because feathers were liable to grow encrusted with bits of rotting flesh during mealtimes. A bird with broad, efficient wings, to fly high and far. A bird with stomach juices stronger than battery acid, to safely digest even carcasses riddled with bacteria. A bird with a bill that can rip and tear, and with a grooved tongue to slurp down slippery gobbets of flesh during a feeding frenzy, and with eyes that can spot a dead deer four miles away.

Without a bird built to such exacting specifications, the carrion would pile up, rot away and spread disease. In India, after the vultures disappeared, the owners of livestock found this happening with their cattle carcasses. Lal Singh Bhujel, a tourist guide who lives near the breeding centre in Rajabhat Khawa, also tends to a dozen head of cattle; his father once kept more, nearly 200. Every time a cow in the village died, it used to be deposited in a shallow ditch near the river, for the vultures to consume. ‘There were so many that my parents wouldn’t even let me out of the house when a cow was in the ditch, because they were afraid the birds would take me away,’ he told me, with a laugh. ‘And now, of course, no one does that, because there aren’t any vultures left.’

Today the farmers of Rajabhat Khawa, like farmers elsewhere in India, must burn or bury the bodies of their livestock. Leaving them outdoors creates problems. For one, feral dogs get at them, and a swelling population of feral dogs poses a higher threat of rabies. ‘Let me be clear. It’s not that, because of the lack of vultures alone, more people are dying of rabies now than before, because rabies treatments have gotten better during this same period,’ Bowden said. Still, 20,000 or so people die of rabies every year in India. ‘And maybe that figure is 20 per cent, or some per cent, larger than it would be if the vultures were all still here.’

The best-known consequence of the vanishing of India’s vultures has been suffered by the Zoroastrians, or Parsis as they’re called in India – a small, prosperous community whose members live mostly in Mumbai and other parts of western India. Whenever this tale is told, it is inflected with a stern tone of warning: beware the ramifications of meddling with the environment, for they are often unforeseen. Nature’s systems are so complex, and her balances so delicate, that a painkiller fed to cows can quickly interrupt the religious traditions of a people half a country away.