 Cassowaries use claws on their inner toe (digit II) for defence, and have been known to disembowel people.All birds however have claws, which are used as general holdfasts and protection for the tip of the digits.The hoatzin and turaco are unique among extant birds in having functional claws on the thumb and index finger (digit I and II) on the forelimbs as chicks, allowing them to climb trees until the adult plumage with flight feathers develop.