London, July 24 (ANI): Researchers in Brazil have unravelled the mystery of the toucan's enormous beak, which has perplexed scientists since Charles Darwin, by finding out that it acts as a natural air conditioning unit for the bird.
Darwin suggested that the toucan's beak was used as a sexual advertisement, while other scientists thought that it might be a specialist fruit peeler or visual warning system.However, Dr. Denis Andrade, of the Universidade Estadual Paulista in Sao Paulo, has finally determined that the beak is used to keep the bird cool.
He says that 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.
He says that the bird increases the flow of blood to the beak, which comprises 30 to 50 per cent of the toucan's surface area, to get rid of more heat.
According to him, 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.
Andrade studied the cooling ability of the toucan's beak by taking readings of the temperatures of six toco toucans, which have the biggest bill of all 38 species of toucans.
He found the bill "routinely accounted" for 30 to 60 per cent of the South American bird's heat loss, but adult birds are so adept at making the most of the beak that it can account for as much as 100 per cent or as little as five per cent.
"In retrospect, it's so obvious that the beak is used to cool the bird - it's large, it has a huge surface area, it's uninsulated," the Telegraph quoted him as saying.
A research article on the study has been published in the journal Science. (ANI)