The Amazon river dolphin (Inia geoffrensis), known locally as the boto, tonina, or pink river dolphin, is the largest freshwater cetacean on Earth — reaching up to 2.8 meters in length and 200 kg in weight. Classified as Endangered by the IUCN, this species inhabits the river systems of the Amazon and Orinoco basins across six South American countries. In Colombia, pink dolphins are distributed across at least 10 departments, from the Amazon lowlands to the eastern Llanos, making the country one of the most important range states for the species.
Population estimates suggest tens of thousands survive across their range, but numbers are declining rapidly — studies in Brazil’s Mamirauá Reserve documented a 50% population drop over a single decade, and in 2023, over 330 dolphins died during an extreme drought and heat event in the Amazon. Colombia’s rivers remain critical habitat, and responsible ecotourism is increasingly recognized as a tool for conservation. This guide covers the species’ biology, the best places to see pink dolphins in Colombia, and the threats they face.
Amazon River Dolphin Facts
- The Amazon River Dolphin is the largest freshwater cetacean in the world, it manages to reach lengths of up to 2.80 meters long and a maximum weight of 200 kilograms.
- Its color varies depending on age, young dolphins and females show grayish colors while adults, and principally the males, turn pink, which gives them their characteristic name.
- There are many theories to explain its color, but many agree it is a result of the wear and tear of their skin, and some scars.
- Scientists discovered that river dolphins come from a very ancient lineage that inhabited the seas.
- Its behavior is very different from sea dolphins. They use to have a solitary life, sometimes in small groups composed of a maximum of four members.
- Their food consists of crabs, river turtles, piranhas, and other river fish.
- The pink dolphin is part of the folklore of the inhabitants of the Amazon and there are many legends and myths around this animal.
Sara Colmenares holds a Doctor of Science (D.Sc.) in Ecology from the Federal University of Rio de Janeiro and a Master’s degree in Botany from the same institution. Her doctoral research focused on palm ecology in the Atlantic Forest, supported by the Rufford Foundation conservation grant.
A published researcher in the Brazilian Journal of Plant Physiology and a member of the Association for Tropical Biology and Conservation (ATBC), Sara has presented her work at international conferences across Latin America and beyond. She was awarded the COLCIENCIAS “Virginia Gutiérrez de Pineda” fellowship, one of Colombia’s most competitive academic distinctions for young researchers.
Sara founded the Sula nature tourism brand in 2018, applying her scientific expertise to develop birding and wildlife experiences across Colombia’s six natural regions. Her fieldwork took her from the cloud forests of the Andes to the Amazon basin, the Pacific coast, and the plains of the Orinoquía. She combined deep ecological knowledge with firsthand experience to create content that is both scientifically accurate and practically useful for nature travelers.
She holds a B.Sc. in Biology from the National University of Colombia, where she also taught plant ecophysiology. She speaks Spanish, Portuguese, and English.