Amazon river dolphin widespread river dolphins. They are present in six countries in South America: Bolivia, Brazil, Colombia, Ecuador, Peru, and Venezuela, in an area covering about . The boundaries are set by waterfalls, such as the Xingu and Tapajós rivers in Brazil, as well as very shallow water. A series of rapids and waterfalls in the Madeira River have isolated one population, recognized as the subspecies "I. g. boliviensis", in the southern part of the Amazon basin in Bolivia. They are also distributed in the basin of the Orinoco River, except the Caroni River and the upper Caura River in Venezuela. The
Xingu-Tocantins-Araguaia moist forests World Wildlife Fund classes the ecoregion "Vulnerable". The Tapajós-Xingu, Xingu-Tocantins-Araguaia and Tocantins/Pindare moist forests ecoregions on the eastern edge of the Amazon basin have all been badly affected by human settlement and deforestation. The Xingu-Tocantins-Araguaia region is the most deforested and degraded part of the Amazon region after the adjoining Tocantins/Pindare moist forests to the east. It is crossed by the Trans-Amazonian Highway (BR-230) from east to west, and by the BR-422 highway along the Tocantins. Most of the land along these roads has been deforested and replaced by pasture or farm fields. The remaining forest has been stripped of