What was considered to be one of the least threatened species of dolphins 20 years ago, has now become one of the most endangered species due to the accelerated and commercialized rape of the Amazon basin and the destruction of the South American tropical rainforest. Ms. Kremer counted the dolphins in July 1998. Social Habits Ecological factors strongly influence social behavior. At river confluences, we have seen as many as 35 pink dolphins cooperatively herding and banking fish, often in association with the gray dolphins. Given that they seem to practice a polyandrous breeding system and females tend to be a bit larger than males, they may have a matriarchal social order.
Males are generally larger.
Tributaries and main rivers of the Orinoco River systems of South America. They tend to gather at confluences of rivers. Calves can be born between July and September, but in front of Dolphin Corners, our lodge becomes a nursery for calves during December-February. A unique characteristic of Inia geoffrensis is the unfused vertebrae in its neck, which allows for the 180-degree head turn, giving them greater flexibility in floodplain forests, grassland, tributaries and shallow waters. They have a hump on their back instead of a dorsal fin.