The Tufted Duck is a medium-sized diving duck with a population of around one million birds throughout temperate and northern Europe and Asia. It occasionally can be found as a winter visitor along both coasts of the United States and Canada. It is believed to have expanded its traditional range with the increased availability of open water due to gravel extraction, and the spread of freshwater mussels, a favourite food. These ducks are migratory in most of their range, and winter in the milder south and west of Europe, southern Asia and all year in most of the United Kingdom. They will form large flocks on open water in winter.
Males are all black except for white flanks and a blue-grey bill. It has an obvious head tuft that gives the species its name. Females are brown with paler flanks and more easily confused with other diving ducks.