Iriri River Iriri River The Iriri River () is a large tributary of the Xingu River in Brazil, in the state of Pará. It is long making it the 116th longest river in the world (with Krishna River, India) and the 15th longest in the Amazon basin. The headwaters are the traditional home of the Panará people. The river rises in the Nascentes da Serra do Cachimbo Biological Reserve, a strictly protected conservation unit established in 2005 in the Serra do Cachimbo. It is one of the headwaters of the Xingu River. It flows for before joining the Xingu, running through the
River tyrannulet mostly contiguous stretches, about 100 to 150 km in width. The rivers in the Amazon Basin, going upstream are the following: Amazon River, (Tocantins, Araguaia— east of the Xingu), Xingu River, Madeira, and Marañón-Ucayali, (in Amazonian Peru). For the Araguaia River, the bird's range continues only downstream to the Tocantin confluence, then down the Tocantins to the Pacific, (500 km east of the Amazon River outlet; the Xingu River confluence range connects to the Tocantins range.) On the Madeira River, from Amazonian Bolivia, the range only extends into the country by 300 km of the 2300 km Madeira River range.