First species of the day for 2014! This time, Ava, Miles and Anna are here, so this is for other kids (big and small) that enjoyed the photos last year – you know who you are. Chestnut-mandibled toucan! Why is the toucan bill so large? People have wondered about this for a long time, but recently scientists found that they use it partly to stay cool. They can change their own temperature as much as 10 degrees C in a few minutes using the beak as a sort of radiator.