“The overall global picture for vultures is abysmal,” said Darcy Ogada, the assistant director of Africa programmes at the Peregrine Fund, an organisation dedicated to saving birds of prey. “Does this story echo that of the canary in the coal mine? Sure does.” In the first major study of the 30-year decline of Pan-African vultures, Darcy and other scientists found that populations of eight species of vultures had declined an average of 62 per cent.

Seven of those species had declined at a rate of 80 per cent or more over three generations, according to the study, published this summer in the journal Conservation Letters. In some parts of Africa, vultures are targeted by poachers, who poison carcasses, hoping to kill the birds so they will not circle overhead and signal park rangers. A vulture can spot a dead elephant in less than 30 minutes, but it can take a poacher more than an hour to hack off ivory tusks. No vulture, no warning.

Here on the Mara, one of the greatest natural strongholds left on the planet, vultures are not directly targeted but are the unintended victims of poisoning of carcasses that is meant to kill large carnivores, like hyaenas, in an effort to protect livestock.

Across Africa, the threats to wildlife are myriad, but much of the attention is focused on the stately animals of the savanna, like lions and elephants.

Forgotten existence

Vultures do not make for pretty postcards, and the local authorities are already stretched thin trying to protect the animals that tourists come to see. “Everyone forgets about the Ugly Bettys of this world,” said Munir Z Virani, who directs the Africa and South Asia programmes for the Peregrine Fund. “We are told all the time by the authorities that they are so busy working to protect elephants and rhinos and other animals that when it comes to the vultures, they are exhausted.”

Anthony Ole Tira, who is a Masai and was raised on these lands and is now the co-owner of the Matira Bush Camp in the heart of the Reserve, stood by a river crossing and pointed to scores of rotting carcasses. One week earlier, 9,00,000 wildebeests, long in the face and often short on luck, had plunged headlong into the river in a panic.

Thousands were trampled to death. That was normal. The rotting remains were not. “Ten years ago, this would have been cleaned by now,” he said. “There are a lot of places along the Mara River that are not as clean as they once were because there are not enough vultures.”

Researchers say they have seen what happens to an ecosystem when the vultures disappear. In 2000, Munir was dispatched to India, where vultures were dying in great numbers but no one knew why. “Everywhere I went, there were dead vultures,” he said. “But everywhere, their remains were in good condition.” The initial hypothesis was that some type of infectious disease was behind the deaths. Soon it became clear that the killer was man-made.

A painkiller, widely used to treat livestock, was poisoning the birds that fed on their carcasses. One carcass with the painkiller in its system could poison hundreds of birds, Virani said, and by 2006, when the painkiller was officially banned, the vulture population had already declined by 97 per cent. Over the same period, there was a drastic rise in cases of rabies in India, with feral dogs taking advantage of the decline in vultures and often spreading the disease to humans.

Munir described what he called apocalyptic scenes, with hordes of wild dogs numbering in the thousands, scavenging the remains of livestock. Estimates vary, but some put the feral dog population in India now as high as 25 million. Roughly 36 per cent of the world’s rabies deaths — the majority of them children — occur in India, according to the World Health Organisation. The battle against the virus is costing the government billions of dollars.

Vulnerable vultures

Over tens of millions of years, vultures have evolved into the most efficient cleaners in the natural world. Because of their highly acidic gastric juices, they can eat flesh infected with a variety of diseases without getting ill. When vultures feast on diseased meat, picking the carcass clean, the threat of wider infection ends. But once vultures are cleared from the skies, they are very hard to bring back. Munir explained that vultures, despite their powerful digestive systems, are fragile.

In Arizona, California and Utah, the Peregrine Fund and its partners have been working for years to bring back the critically endangered California condor, which by 1987 was almost completely wiped out by lead poisoning, with fewer than two dozen birds left. Nearly three decades later, there are around 400, fewer than half of them in captivity. In Africa, Munir hopes that the population decline can be halted and reversed before it reaches the kind of critical situation found in India and other parts of the world. “It is not too late,” he said.