Clangula hyemalis; the Long-tailed Duck is a duck of highland regions and northern Iceland coastal regions (also common at Mývatn). I have seen this species quite often also along Iceland's north coast. Only the male has elongated tail feathers. On the phot of the swimming male the elongated tail feathers can be seen behind the bird just under the water. Their color pattern makes it almost impossible to confuse them with other species. During winter it generally stays at sea where it feeds on small crustaceans.