The fuzzy photos of a “lost tribe” in the Amazon released in May turned out to be somewhat of a hoax—the government had known about the tribe for decades—but they raised a real question: How do you protect uncontacted tribes without, well, contacting them? To answer this, the Brazilian government has come up with a way to track the tribes from a distance, using high-altitude planes equipped with body-heat sensors.
The “lost tribe” photos were released by Funai, a group dedicated to protecting isolated people from land encroachment by loggers and farmers. Antenor Vaz, the head of Funai, says the body-heat sensors will allow the government to identify tribal territories without exposing the tribes to Western infectious diseases. The government can then set up protected areas and leave them in peace. The Brazilian constitution stipulates that all Indian ancestral lands must be turned over the tribes; currently, about 11 percent of Brazil technically belong to Indian tribes.