Deep in the Amazon forest, thousands of people still live in from the rest of the world. In a recent press release, the Brazilian government confirmed the existence of another isolated tribe of about 200 people living in the Vale do Javari reservation. The 200 people living in the Vale do Javari reservation. The reservation, located near the Peruvian border, is about the size of Portugal. At least another 14 isolated tribes, with a total population of about 2000, call the area home. The newly observed group lives on four large straw-roofed buildings and grows corn, peanut and other crops. Brazil's National Indian Foundation (BNTF) first noticed the reservation in the forest using satellite maps, but it wasn't until April that an airplane expedition was able to confirm the tribe's existence. "The work of finding and protecting isolated groups is part of Brazilian public policy," said the BNIF officer for Vale do Javari, Fabricio Amorim. "To confirm something like this takes years of hard work." BNIF estimates there are 68 isolated tribes living in the Amazon. The organization uses airplanes to avoid disturbing the tribes through personal contact, but that doesn't mean others are so respectful of their right to privacy. Illegal fishing, woodcutting and hunting bring people into the protected area. Oil exploration on the Peruvian side of the border is another threat. All kinds of criminals also invade the lands of the local groups, said Amorim. The outsiders can damage the land and influence the cultures of indigenous peoples. They can also bring diseases which can wipe out the whole population that still lack even basic antibiotics . Brazil's indigenous peoples won the legal right to their traditional lands in Brazil's 1988 Constitution, which stated that all indigenous lands shall be divided and turned over to tribes within five years. Indigenous groups now control 11 percent of Brazil's territory, including 22 percent of the Amazon. Allowing indigenous groups the right homelands is not just a matter of human rights. The rest of the world can benefit from their knowledge. Mark Plotkin has spent years living with the people of the Amazon and learning from their traditional healers. In his lecture, he pointed out that many useful materials and knowledge, including numerous drugs, can be gained from listening to the indigenous groups of the Amazon. Besides this, they are also more effective at protecting the land, and less expensive, than hired rangers . From the passage we can learn that the tribes in the Amazon forest    _    .
only live on a reservation designated for them prefer straw-roofed buildings to wooden ones keep contact with the outside world through airplanes have the legal right to the land they live on