The Toco Toucan of South America has evolved to stay cool in the sweltering heat of the tropics. Relative to its body size, the Toco Toucan has the largest bill of any bird in the world, accounting for a third of the body’s entire surface area. It’s also laced with blood vessels and wholly without insulation — features that make it a superb structure for getting rid of excess body heat. Learn more at BirdNote.org.