sheathbill

White-plumaged shore bird of the southern hemisphere, family Chionididae. The snowy or greater sheathbill Chionis alba occurs in the Antarctic region and grows to a length of 39 cm/15 in. It feeds on penguin and seal excrement, and by stealing what it can from penguins feeding their young with half-digested krill.

At breeding times, sheathbills eat unattended penguin eggs. Their own nests are conglomerations of litter – bone, guano, and the remains of dead chicks. They lay two or three eggs but only raise a single chick, probably sacrificing the weaker chick as food for the stronger. Sheathbills are unique as Antarctica's only genuine land-bird, spending most of their time scavenging in penguin colonies.