Why Do Toucans Have Such Big Bills?
Toucans use their long bills to pick fruit to eat, but no one is sure why their bills are so big. One possibility is that the toucan’s enormous beak originally developed to consume some long-extinct giant fruits. Toucans are birds of the woodlands and forests of Central and South America.
The bird’s bill, which is often larger than its body, gives it an ungainly, comical appearance. But in spite of its huge size, the thin-walled bill is lightweight and not a burden for the toucan. In sunlight, the brightly colored bill glows like a stained glass window.
Toucans have the biggest bill in the avian world in comparison to body size and its purpose has perplexed and fascinated naturalists in equal measure for centuries. The naturalist Charles Darwin suggested it was used as a sexual advertisement while other scientists thought it might be a specialist fruit peeler or visual warning system.
However, new research has found the beak is used to keep the bird cool. Researchers in Brazil found the beak is able to cool the bird because heat is transferred into it through the blood and can then be dissipated into the air.
By increasing the flow of blood to the beak, which comprises 30 to 50 per cent of the toucan’s surface area, the bird succeeds in getting rid of more heat. The beak is so big that it has been found to rival an elephant’s ears in helping to cool the animal down when the weather gets hot.