The Smew (Mergellus albellus) is a species of small duck that is somewhat-related to typical mergansers and the goldeneyes; it is more closely related to the goldeneyes. It breeds in the northern taiga (the coniferous evergreen forests of sub arctic lands) of Europe and Asia. It is found mainly on fish-rich lakes and slow moving rivers. It migrates away from this area and winters on sheltered coasts and inland lakes of the Baltic Sea, the Black Sea, northern Germany, and parts of Great Britain. On lakes, it is found mostly along the waters edge, and often under small trees.

The drake Smew is distinct with its “˜cracked ice’ appearance. It looks very black-and-white in flight. Females and young are mainly gray with chestnut foreheads and crowns. The female is sometimes mistaken for the Ruddy Duck when seen at a distance. It has oval white wing-patches in flight. The bill has a hooked tip and serrated edges that help it catch fish when it dives for them.

The Smew breeds in May. It needs trees in order to successfully breed. The female lays six to nine cream-colored eggs. It nests in abandoned tree holes, such as woodpecker nests. It is shy and flushes easily if disturbed. This species is not considered threatened by the IUCN.