In Amazonia, Defending the Hidden Tribes

Like most Kayapo Indians, the brothers -- named Bepro and Beprytire -- live in a government-demarcated reserve, wear modern clothing and get energy from solar-powered generators. But the four unclothed visitors were a different kind of Kayapo.

They spoke in an antiquated tongue that seemed a precursor to the language spoken in the village, located in the Capoto-Jarina Indian Reserve in central Brazil. The four men had come from a tribe that had remained in the forest, the brothers said, untouched by the modern world.

Over the next seven days, the doubt expressed by the villagers evaporated when they saw more than 60 of the Indians emerge from the forest, sleeping in huts on the edge of the village.

Then as quickly as they had come, the Indians disappeared. They haven't been seen since.

The Indians' brief appearance this spring was enough to put them into the center of a debate that is increasingly challenging governments throughout the Amazon region: How should the rights and territories of isolated populations be protected when the locations of those groups remain largely unknown?

In recent months, Brazil and Peru have set aside protected areas for so-called uncontacted groups, which have never been spoken to and rarely -- if ever -- glimpsed. Brazil is believed to have more uncontacted tribes than any country in the world, and the government this year announced that as many as 67 tribes could be living in complete isolation -- considerably more than the 40 estimated earlier.

Previously uncontacted tribes have been discovered periodically since deep Amazon exploration began in the late 1800s. In the 1970s, for example, such tribes as the Panara were found as construction crews built roads into the forest, and periodic discoveries of small tribes continued in the following decades.

Today, because the Amazon region is shrinking by thousands of square miles a year, the chances of unintentional encounters involving such groups grow. The issue has become a significant focus for the Federal Indian Bureau, or Funai, the government agency that oversees indigenous groups.

Indigenous rights advocates have issued calls to protect largely unexplored areas of the forest from logging and mining. But the renewed focus on uncontacted groups has also sparked suspicions among skeptics, who believe the groups could be more mythical than real and suspect the numbers are exaggerated by special interest groups seeking to block exploration projects.

"It is like the Loch Ness monster," said Cecilia Quiroz, legal counsel for Perupetro, the Peruvian state agency in charge of doling out prospecting rights to energy companies eager to explore the country's vast interior. "Everyone seems to have seen or heard about uncontacted peoples, but there is no evidence."

'Why Now and Why There?'

Megaron Txucarramae grew up in the village where the uncontacted Indians approached the two brothers in late May. He was 2 years old when anthropologists first made contact with his own branch of the Kayapo tribe in the 1950s. He regularly heard his elders tell the story of how one part of the tribe had fled the anthropologists' advances to remain alone in the woods, never to be seen again.