The Bolivian River Dolphin in the Tijamuchi and Ibare Rivers (Upper Madeira Basin) during rainy season in “La Niña” event

This study determined the density of Bolivian bufeo (river dolphin) in two rivers with similar habitat characteristics during “La Niña” event of 2008. The density varied between 1 ind./km2 in Tijamuchi river and 0.2 ind./km2 in Ibare river. Previous studies showed higher densities in both rivers. We suggest that this reduction could be related to greater levels of human activity and the abnormal floods during “La Niña” affecting water quality due to the incorporation of garbage, latrines contents and sewage into the river.