Scientific name: Gavia immer (Brunnich, 1764)
Bird group: Divers
Field characters. 69-91 cm. In breeding plumage with glossy black head and neck, striped black-and-white incomplete collar on neck and similar short throat band; upperparts entirely covered with white spots. Underparts white, with black streaks at sides of breast. Bill blue-grey with dark culmen. On the water, squarish head and bill are held horizontal. In winter plumage, upperparts dark grey-brown with characteristic faint dark band at base of neck; crown usually darker than upperparts.
Voice. In flight a low, "barking" "kwuk"; in breeding area a series of persistent, plaintive notes.
Distribution. In the area only regularly breeding on Iceland (100-300 pairs).
Habitat. Prefers medium-sized or large, undisturbed and remote lakes with deep and open water in the northern coniferous zone and in the tundra region.
Food. Chiefly fish (up to 28 cm), but captures also crustaceans, molluscs, annelids, and amphibians. Diving depths usually between 4-10 m.
Eggs. Irregular, small dark brown spots, occasionally a few larger black blotches; ground colour olive green/dark brown. Texture slightly glossy. Shape subelliptical/long elliptical. Size 90 x 58 mm (84-102 x 54-63), weight 167 g.