The ferruginous duck (Aythya nyroca), also known as ferruginous pochard, common white-eye or white-eyed pochard, is a medium-sized diving duck from Eurosiberia. The scientific name is derived from Greek aithuia an unidentified seabird mentioned by authors including Hesychius and Aristotle, and nyrok, the Russian name for a duck. The breeding male is a rich, dark chestnut on the head, breast and flanks with contrasting pure white undertail coverts. In flight the white belly and underwing patch are visible. The females are duller and browner than the males. The male has a yellow eye and the females have a dark eye.