We all know that animals live in habitats that provide them with food and shelter to survive. But they also need to develop unique ways to communicate and obtain food. These physical adaptations to a certain environment take generations to evolve, yet this is what allows different species of animals to survive in their surroundings. The pink river dolphins (Inia geoffrensis), also known as the ‘Amazon river dolphins,’ are an example of a species that has such adaptations. They are born gray and become pink as they age. The change to pink coloring is caused by their skin becoming more translucent as they get older -- the pink color that you see is actually the blood flowing through the capillaries beneath their skin. They are one of five freshwater species of dolphins in the world and are mainly found in the tributaries and main rivers of the Orinoco River system of South America.

With a unique adaptation of an un-fused vertebrae in its neck, the pink river dolphin can turn its head 180-degrees when feeding, allowing it a diet from floodplain forests, grasslands, tributaries and shallow waters. Because of this excellent flexibility, they can weave in and out of freshwater ecosystems, making humans their only natural born predator. The pink river dolphins are lone hunters that have excellent eyesight and use sonar to locate prey in murky waters.

Today the pink river dolphin is at risk for extinction in some areas and is an endangered species because of humans’ role in the destruction of the Amazon rainforest. These highly intelligent mammals have a brain capacity that is 40% larger than that of humans. However, the dolphins are threatened by habitat destruction, dam projects, mercury poisoning, entangling in fishing nets, pollution, and boat traffic. Because adaptations take generations to evolve, the pink river dolphin continues to be vulnerable to human activities.

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