On the forested western edge of Maranhao state in north-east Brazil lives the Awa tribe. One of only two nomadic hunter-gatherer tribes left in Brazil, the Awa have long lived in this area, which lies between the equatorial forests of Amazonia and the drier savannas to the east. Towards the end of the 1960s, geologists discovered that the world's richest reserves of iron ore lay under the soil, and the US, Japan, World Bank and EEC, as it was then, loaned billions of dollars to Brazil to finance the extraction, in return for exports of minerals.
The Greater Carajas Programme was devastating for the environment and its indigenous peoples. It was a mammoth agro-industrial complex, consisting of a dam, tarmac roads, aluminium smelters using timber from the forest, cattle ranches, and a 560-mile long railway that cut through the Awa's territory on its way to the coast. At its heart was an open-air iron mine so big it could be seen from space. And into this region of precious bio- and cultural diversity poured an army of ranchers, settlers and loggers, for there was a fortune to be made from the forest.
But there was a major problem for the prospectors: the Awa were in the way. So the invaders started to massacre them. Some were particularly inventive in their killings: several Awa died after eating flour laced with ant killer, a "gift" from a local farmer. Others were just shot where they stood – at home, in front of their families.
Karapiru, a gentle, tall man, thought he was the only one of his family to survive an attack. The killers murdered his wife, daughter, mother, brothers and sisters; his son was wounded and captured. Karapiru escaped and, severely traumatised, fled far into the forest, lead shot embedded in his lower back.
For 12 years, Karapiru was on the run, fleeing the invaders. He walked for nearly 400 miles across the forests and plains of Maranhao, crossing the sand dunes and rivers that flow into the Atlantic Ocean. He was terrified, hungry and alone. He survived by eating honey and small birds such as parakeets, doves and red-bellied thrushes. At night, when howler monkeys called from the canopy, he slept high in the boughs of vast copaiba trees. When the solitude became too much, he would talk quietly to himself, or hum as he walked.
More than a decade later, on the outskirts of a town in the neighbouring state of Bahia, Karapiru was seen by a farmer walking through the black ash of a burnt patch of forest, carrying a machete, arrows, and a chunk of smoked wild pig. The farmer gave him shelter, and alerted the National Indian Foundation (Funai) – the government body responsible for Indian policy – which, in turn, sent a young Awa man called Tiramucum to talk to this "unknown" Indian, whose language no one could understand. The meeting was one Karapiru could never have imagined during his 12 years on the run: the young man was his son.
Karapiru has since remarried, has a young daughter and lives in the Awa village of Tiracambu. His life since his return has been typical of the 360 members of the Awa tribe. They spend their days hunting for game such as peccary, tapir and monkey, with 6ft bows made from the irapa tree and gathering forest produce such as babacu nuts and acai berries. Vultures, bats and the three-toed sloth are forbidden as prey for eating. They nurture orphaned animals as pets, share their hammocks with raccoon-like coatis and split mangoes with green parakeets. Awa women even breast-feed capuchin and howler monkeys and have also been known to suckle small pigs.
At night, the Awa travel with torches made from tree resin, carrying the embers of a fire as they move from one hunting ground to another. And when the moon is full, the men – hair speckled white with king vulture down – in a chant-induced trance – commune with forest spirits, during a sacred ritual lasting till dawn. Their existence is one of intimate connection with the forest, which provides food, shelter and spiritual solace.
But Karapiru's way of life, and that of all Awa members, including the 60 to 100 who are still uncontacted, is once more in danger. A federal judge has described the situation as a "real genocide". Survival International has now launched a campaign to protect their lives and lands, with the backing of the actor Colin Firth.
Survival has recently discovered that Awa forests are now disappearing faster than in any other Indian area in the Brazilian Amazon. "Satellite images reveal that over 30 per cent of one territory has already been destroyed, despite the land having been legally recognised," says Fiona Watson. Heavily armed ranchers and loggers, with the grisly help of hired guns, are shooting the Awa on sight. And the Carajas train passes just metres from the forest where uncontacted Awa live.
Despite surviving violence and disease over the past two centuries, the Awa will not survive if they lose their homeland. "The loggers are destroying all the land," Pire'i Ma'a, an Awa man, said. "Monkeys, peccaries and tapir are running away. Everything is dying. We are all going to go hungry."
Their disappearance is not inevitable. Their lands need to be protected and their rights respected. In Survival's campaign film, Colin Firth says: "One man can stop this: Brazil's Minister of Justice. He can send in the federal police to catch the loggers, and keep them out for good. But we need enough people to message him. This is our chance, right now, to actually do something. And if enough people show they care, it will work."
To save this planet's most threatened tribe, please visit: survivalinternational.org/awa
Joanna Eede is editorial consultant to Survival Internationa and author of 'We Are One: A Celebration of Tribal Peoples'