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.
The ferruginous duck prefers quite shallow fresh waterbodies with rich submerged and floating vegetation with dense stands of emergent vegetation on the margins. In some areas it will use saline or brackish pools or wetlands. On passage and wintering will also frequent coastal waters, inland seas and large, open lagoons.
The breeding range of the ferruginous duck is from Iberia and the Maghreb east to western Mongolia, south to Arabia, although in the west is now scarce and localised and locally extirpated in some countries. The duck winters throughout the Mediterranean Basin and the Black Sea, smaller number migrate into sub-Saharan Africa via the Nile Valley. Eastern birds winter in south and south-east Asia.