Long-tailed Duck (Clangula hyemalis)
The Long-tailed Duck C. hyemalis is a circumpolar marine species that breeds mainly in the Arctic tundra and winters further south, often far out at sea. It is estimated that only around 3,500 birds winter in Britain; most of these are thought to breed in Fennoscandia or northwest Russia and Sussex is on the southern edge of their wintering range. During 1992-2009, wintering numbers in the Baltic Sea, which held 70% of the world population, declined by an alarming 65% for unknown reasons.
In Sussex it is a very scarce passage migrant and winter visitor and a rare non-breeder in summer. The above image, of a spring plumaged female, was recently taken in Lancashire.
Cowser, R., 2014. Long-tailed Duck. The Birds of Sussex. Thetford: British Trust for Ornithology (BTO) Books on behalf of the Sussex Ornithological Society, p. 125.
Wilson, T.J. 1996. Long-tailed Duck. Birds of Sussex. Sussex Ornithological Society, pp. 175-176.