Amazonian societies on the brink of extinction

Abstract

Objectives: Greater Amazonia harbors as many as 100 locations of isolated indigenous peoples. Few options are available to assess the demographic health of these populations given their limited contact with the outside world. Remote sensing offers one option.

Methods: An isolated village in Brazil near the Peruvian border is visible with Google Earth imagery from 2006. The area of the fields and village, as well as the living area of the four longhouses, are measured and compared to population-by-area measurements for 71 other Brazilian indigenous communities.

Results: The estimated population of the village is no more than 40 people. A village as small as this one, if it has become disconnected from a metapopulation, risks imminent extinction if it has fallen below a minimum viable population size.

Conclusions: An active remote surveillance program is urgently needed to track the movements and demographic health of isolated peoples in hopes of improving their dire chances for long-term survival. They need protected areas that are large enough to mitigate against external threats.