Scientific name: Aythya ferina (Linnaeus, 1758)
Bird group: Ducks
Field characters. 42-49 cm. Long sloping forehead with high crown. Male with uniform chestnut-red head and neck, contrasting with vermiculated light grey body and black breast, under- and upper-tail. In flight with broad, pale grey stripe across entire upper-wing, contrasting with dark grey forewing. Bill dark grey with broad pale blue-grey band across middle and black tip. Female yellowish-brown, with dark brown crown and hoary areas round base of bill, on cheeks and throat; back, scapulars and sides vermiculated grey-brown; bill as male but duller. Male in eclipse resembles female but upperparts more grey. Juvenile resembles female but upperparts less vermiculated grey.
Voice. Generally silent. Female has harsh growl.
Distribution. Not a common breeding bird in Europe but locally a very common winter visitor.
Habitat. In the breeding season, occurs on open water of lakes, large ponds with floating vegetation and ample supply of submerged plant and animal food; prefers habitats with ample cover. Outside the breeding season, gathers on open, preferably fresh waters.
Food. Feeds mainly by diving up to 2.5 m deep, but feeds also with head and neck immersed and by dabbling on the surface. Takes seeds, rhizomes, buds, shoots, leaves, and tubers of aquatic plants, and animal matter (crustaceans, molluscs, annelids, insects, tadpoles).
Eggs. Unmarked, ground colour green-grey, seldom bright green. Texture smooth, not glossy. Shape subelliptical/short subelliptical/elliptical. Size 62 x 44 mm (56-68 x 39-47), weight 68 g (61-73).