The last recorded mention of Brazil's Naua people was a 1906 local newspaper headline: "Last Naua woman marries."
Since then the Naua were believed to be wiped out by war, disease, and slavery. The memory of the Amazonian jungle tribe survived through books and their local fame in the Acre state, where a street, a theater, a coffee, a stretch of river, and even a local soft drink are named after them.
So when a group of Indians turned up in the remote town of Cruzeiro do Sul late last year and identified themselves as Nauas, Antonio Pereira Neto could hardly believe it.
Mr. Pereira, an anthropologist with the Brazilian government's National Indigenous Peoples Foundation (Funai), says when he went to check out the information and found 250 Nauas living as rubber tapers and hunters, he was flabbergasted.
"It's incredible that today in the 21st century they are making themselves known to us like this," Pereira said last week, the day after authorities made the unexpected announcement. "We thought they had disappeared. It is a very pleasant surprise."
The "discovery" of the Naua almost 100 years after they were last heard of is an exceptional occurrence even in Brazil, a country with more than 200 indigenous tribes scattered across the largest jungle on earth.
The most unusual thing about the emergence of the Naua is that it was the Indians who came looking for civilization and not the other way around. For years, Funai sent explorers into the jungle and in small planes across the forest in search of undiscovered tribes. Last week's announcement is proof that no matter how hard they look they may never really know how many undiscovered tribes are still out there.
"It gives us a boost ... but the important thing is not finding them, it is protecting their environment and their natural habitat," says Funai researcher Elimenton Alencar. "If they don't face any threat, we try and leave them alone."
After decades of trying to incorporate Indians into modern society, the Brazilian government changed policy in the 1980s and sought to place more importance on preserving the Indians' traditional way of life. The strategy makes sense, say experts on indigenous peoples, because under the previous assimilation policy Indians often succumbed to the white man's diseases, vices, or culture.
"The old policy of trying to integrate them into society was a disaster," says Malu Ochoa, a coordinator at the Acre-based Pro-Indian Commission, a nongovernmental organization that has promoted indigenous causes for 21 years. "Funai's policy now is to protect them, to leave them alone. It has been quite successful."
Anthropologists say they do not even try to study the "new" Indian tribes and prefer to wait years or even decades before carrying out research into their ethnicity or language.
As they wait, they try to forge a bond of trust with the Indians, a slow process, given that almost all the outsiders the Indians have come into contact with have probably used or abused them.
"We don't actually go after these groups any more unless they are threatened," says Mr. Alencar. "Once we know they are there we leave them to be as autonomous as possible. First of all, we need to win their confidence and that can take five, 10 years. They don't know who we are, they don't know the difference between a Funai explorer and a hunter there to kill them."
The situation is slightly different with the Naua. Not only did the Naua make contact with Funai and not the other way around, they are also not considered a "new" tribe because experts already knew about them. One anthropologist who was in the area in 1977 even spoke with the tribe - but never realized they were Naua, partly because they did not describe themselves as such.
But with indigenous issues gaining a new gravity in Brazil, the Naua came to identify themselves as Indians and learn about their rights, including their right to possess the land they have always lived on.
That land is now part of the Serra do Divisor National Park, a 900,000-hectare (2.2-million-acre) forest near Brazil's border with Peru. Under Brazilian law, national parks should be uninhabited, and the government recently tried to clear natives from the area. When the Naua were told they would have to leave the only home they have known, their leaders traveled two days by canoe to the town of Cruzeiro do Sul to ask a Roman Catholic organization working for indigenous peoples' rights to help secure title to their homeland.
Since constitutional changes granted Indians such rights in 1988, the number of tribes making legal claims to territory has "increased greatly," says Alceu Mariz, a Funai anthropologist involved in setting up Indian reservations. "It is partly because of the pressure from other people seeking to take their land and partly because they are now more conscious they have rights. They are more and more aware of the importance of fighting for the land they occupy."
Since the land is so often remote and rich in resources like wood and minerals, the area occupied by Indians also comes under threat from outsiders. So Funai plans to set up observation posts around the Naua territory to try and stop outsiders from disturbing the tribe.
In some respects, however, it is already too late. The rubber tapers and explorers who swarmed into the Amazon during the rubber boom at the end of the 19th century brutally subjugated the Indians and prevented them from carrying out their ancient rituals or even speaking their native language. Pereira found that most of the 250 full-blooded and 350 mixed blood Indians he encountered have lost their traditional culture and only a handful still speak their mother tongue.
Even so, the incredible discovery has electrified anthropologists who now have even more reason to believe there are other tribes living in happy obscurity in the Amazon, large swaths of which, even with satellite photos and other high technologies, remain mysteries to all but those who live there.
The discovery of the lost tribe is the first for years in Acre, the most westerly state in Brazil and one so dense that authorities earlier this year discovered they were running three schools that were actually in neighboring Bolivia and Peru.
But the Naua may not be the last.
"We are studying another tribe, the Arara," said Pereira. "I have just sent a detailed report to (the capital) Brasilia. I'd say that in Acre there are four tribes to be revealed and in Brazil, maybe as many as 40."
(c) Copyright 2000. The Christian Science Publishing Society