The bill of the keel-billed toucan may appear heavy, but it is actually very lightweight. Their bills consist of hollow bones and a protein called keratin, the same material found in human hair, nails and skin. #EarthCapture by praveensiddannavar . . . . #BBCEarth #Toucans #KeelBilledToucans #Birds #BirdBills #AmazingAnimals #WildlifePhotography