Brownish elaenia the Xingu River in the south of Pará state, North Region, Brazil; it ranges upstream on the Xingu for 700 km, then a tributary to the west of the Xingu, the Rio Iriri, for another 700 km. The next upstream tributary for the bird's range, is the Madeira River in the Amazon Basin's southwest, Amazonas state. The range proceeds 2400 km upstream into the headwaters of the Madeira in northern Bolivia. To the west the brownish elaenia's range continues as the Amazon River becomes the Marañón River and proceeds to the headwaters in northern Peru; this is also along the
Xingu peoples number had been reduced by foreign epidemic diseases such as flu, measles, smallpox and malaria to less than 1,000. Only an estimated 500 Xingu peoples were alive in the 1950s. The Brazilian Villas-Bôas brothers visited the area beginning in 1946, and pushed for the creation of the Parque Indígena do Xingu, eventually established in 1961. Their story is told in a film, "Xingu". The number of Xingu living there in 32 settlements has risen again to over 3000 inhabitants, half of them younger than 15 years. The Xingu living in this region have similar habits and social systems, despite different