The White-crested Duck is a species of duck found in Eurasia and North America. It is also known as the SMEW, which is a four letter word that can be used to solve a crossword puzzle. The White-crested Duck is a medium-sized diving duck with a white crest on its head. It has a black back and wings, and a white breast and belly. Its bill is red and its legs are grey. It is a migratory species, breeding in northern Europe and Asia and wintering in southern Europe and Africa.