The 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.
The Long-tailed Duck is gregarious, forming large flocks in winter and during migration. They feed by diving for mollusks, crustaceans and some small fish. Although they usually feed close to the surface, they are capable of diving to depths of 60m (200 feet). (source: Wikipedia)