This article is part of our series on South American animals.
Probably the most disappointing animal in the Amazon is the pink dolphin. It just doesn’t live up to its name. Pink connotes cuteness like a 5-year-old’s birthday dress or perhaps high fashion like a flashy flamingo. Pink dolphins, also called botos or an Amazon river dolphin, are neither. In fact, they don’t even live up to our expectations of a dolphin: sleek, graceful, and beautiful.
If you took a wad of chewed bubble gum out of your mouth, rolled it into a fat, lumpy tube and stuck a snout on it, you’d have a pink dolphin miniature. These are not lovely creatures.
Amazon river dolphins weigh up to 450 pounds and can grow to be 8 feet long. And though they can’t compare in grace to their salt water cousins, Amazon river dolphins are incredibly adapted to their habitat. They are the only dolphin species able to move its neck side to side. This horizontal motion—rather than vertical one—and disjointed vertebra allow botos to swim in much shallower water than the average dolphin. The Amazon River rises and falls about 30 feet year each; for several months Amazon dolphins swim among trees in the flooded forest (called várzea) in water only a few feet deep.
Pink dolphins also evolved to have smaller, more versatile fins then other dolphins, which allow them to navigate in tight spots, and their long, spear-like snout is ideal for snapping fish out of root tangles and underwater shrubs. Their beady eyes are ineffective; they use echolocation to orientate themselves.
The Amazon river dolphin is the largest of six fresh water dolphins. It shares the Amazon and Orinoca River Basins with the lithe tucuxi dolphin. Tucuxis are similar to bottle nosed dolphins and can live in both fresh and salt water. If you see a dolphin jumping in the Amazon River, it’s a tucuxi, also called a grey river dolphin.
Dolphins in the Amazon have healthy populations, believed to number in the tens of thousands. Other river dolphins, all found in Asia, aren’t so lucky. The Yangtze river dolphin, also called a baiji, is considered functionally extinct, meaning there are too few species left to rebuild a sustainable population; they died out due to increased fishing, boat traffic, and loss of habitat. The Ganges and Indus river dolphins are both endangered, primarily due to increased human populations and dams. The incredibly adorable Irrawaddy dolphin, easily identified by its short and rounded beak, lives in various locations in Southeast Asia and is a threatened species.
Not to be confused with Amazon pink dolphins are Indo-Pacific humpback dolphins that live in the salty Pacific and Indian Oceans. These dolphins can turn a pinkish color as they age, and are often mistakenly called pink dolphins.
There are several reasons Amazon dolphins, considered a vulnerable species, have so far escaped the fate of other freshwater dolphins. The Amazon is still scarcely populated with many remote tributaries, though mining, drilling, and increased fishing is worrisome. It is illegal in both Peru and Brazil to kill Amazon dolphins, but stronger than the law are traditional beliefs. According to Amazonian folklore, pink dolphins are shape shifters that come ashore at night to tempt villagers into indiscretion and impregnate young women. Solo swimmers, even during the day, are at risk of being swept away by the dolphins and trapped in their underwater world. Because villagers believe the dolphins are magic, abet evil magic, they’re respected and it is considered extremely bad luck to kill one.
The real mystery, however, is why pink dolphins are pink. Experts seem to vary on this one. Some say they become pink when they’re scared or excited, other believe it is scar tissue, while another theory is that it has to do with age. The most common belief is that some Amazon dolphins appear pink due to blood vessel close to the surface of their skin.
Photo credits : Steven Ryan, Zemlinki!, Jai Mansson