The toucan's bill, 1/3rd its body, has been theorized to attracted mates, peel fruits or for territorial defense. A new report says the beak acts like a radiator since birds don’t sweat. When a toucan needs to cool, its beak heats up. The beak's surface area allows heat to quickly dissipate; for example, when a toucan lowers its body temperature in preparation for sleep, it cools 10°C in minutes. When outside temperatures rose, the bill heated up, but the bird’s core body temperature did not.
