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Why Are Pink Dolphins Pink?
Amazon river dolphins are born grey and turn pink as they age. Here's why pink dolphins are pink – and why the males are the pinkest of all.
A bright pink dolphin sounds like a fairy tale, but the Amazon river dolphin, or boto, is real, and some adults are as pink as bubblegum. So where does the colour come from? Not from its food, and not from the sun.
Pink dolphins are born grey
A baby pink dolphin is born dark grey. As it grows up, its skin gradually turns lighter, and by adulthood many are pale pink, mottled pink and grey, or bright pink all over.
So why are they pink?
- Scar tissue: botos play rough, and males fight a lot. Each scratch and bite heals as pinker skin, so the older and more battle-scarred a dolphin is, the pinker it gets.
- Blood vessels near the skin: the pink glow comes partly from blood showing through thin skin, a bit like a person blushing. When a boto is excited or active, it can turn even pinker.
- Less sun: the Amazon’s murky, tea-coloured water blocks a lot of sunlight, so there’s less need for dark, protective skin.
Why are males pinker than females?
Because they fight more. Adult males are bigger, rougher and covered in more scars, and those scars heal pink. Some scientists think the pink colour may also help males impress females, showing off how tough they are.
A pink dolphin’s colour is a little like a pair of old jeans: the more rough-and-tumble it’s been through, the more faded and pink it gets.
Strange but trueLocal legends along the Amazon say the boto can turn into a handsome man at night, who comes to village parties wearing a hat to hide his blowhole.
Is it the food, like flamingos?
No. Flamingos turn pink from pigments in the shrimp and algae they eat. Botos eat fish, crabs and small turtles, and their colour comes from their skin and blood, not their diet.
Other pink dolphins
- Indo-Pacific humpback dolphin: often called the Chinese white dolphin or, in Hong Kong, the pink dolphin. Adults turn pinkish-white, partly because of blood vessels that help them shed heat.
- Pinky the Louisiana dolphin: a rare pink bottlenose dolphin first spotted in 2007 in Calcasieu Lake, Louisiana. Her colour comes from a genetic condition, probably albinism, not from the same causes as the boto.
Are pink dolphins endangered?
Yes. The Amazon river dolphin is listed as Endangered. Botos are killed for use as fishing bait, drown in nets and suffer from dams, mercury pollution and droughts that dry out their rivers. Respectful tourism, where people watch them from boats without feeding them, can help local communities value living dolphins.
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