The Smew (Mergellus albellus) is a species of duck, and is the only member of the genus Mergellus. This species breeds in the northern taiga of Europe and Asia. It needs trees for breeding. The Smew lives on fish-rich lakes and slow rivers. As a migrant it leaves its breeding areas and winters on sheltered coasts or inland lakes of the Baltic Sea, the Black Sea, northern Germany and the Low Countries, with a small number reaching Great Britain.
The only mutation, thus far, is the White Mandarin. White Mandarin males are white. They have the same markings as the Mandarin, and wherever there is a dark colour on the Mandarin, the White Mandarin haves a light chestnut/tan colour. The beak is a bright red. Females are all white. Some may have a chestnut/tan stripe in a few of the flight feathers.
Long-tailed Duck or Oldsquaw (Clangula hyemalis) is a medium-sized sea duck. It is the only living member of its genus, Clangula; this was formerly used for the goldeneyes, with the Long-tailed Duck being placed in Harelda.