Smew Duck

The smew (''Mergellus albellus'') is a species of duck and is the only living member of the genus ''Mergellus''. ''Mergellus'' is a diminutive of ''Mergus'' and ''albellus'' is from Latin ''albus'' "white". This genus is closely related to ''Mergus'' and is sometimes included in it, though it might be closer to the goldeneyes (''Bucephala''). The smew has hybridized with the common goldeneye (''B. clangula'').

Etymology

The smew was formally described in 1758 by the Swedish naturalist Carl Linnaeus in the tenth edition of his ''Systema Naturae'' under the binomial name ''Mergus albellus''. Linnaeus based his account on the description published in 1757 by another Swedish naturalist, Fredrik Hasselqvist. Linnaeus specified the type locality as Europe but this was restricted to the Mediterranean near Ä°zmir in Turkey. The smew is now the only living species placed in the genus ''Mergellus'' that was introduced in 1840 by the English naturalist Prideaux Selby. The species is monotypic: no subspecies are recognised. The genus name is the Latin word for an unknown seabird, perhaps a cormorant. The specific epithet ''albellus'' is a Latin diminutive of ''albus'' meaning "white".

The term ''smew'' has been used since the 17th century and is of uncertain origin. It is believed to be related to the Dutch ''smient'' ("wigeon") and the German ''Schmeiente'' or '' Schmünte'', "wild duck." It is probably derived from ''smee'', a dialectal term for a wild duck.

Description

The drake smew, with its 'cracked ice' or 'panda' appearance, is unmistakable, and looks very black-and-white in flight. The females and immature males are grey birds with chestnut foreheads and crowns, and can be confused at a distance with the ruddy duck; they are often known as "redhead" smew. It has oval white wing-patches in flight. The smew's bill has a hooked tip and serrated edges, which help it catch fish when it dives for them.

The smew is long, with a wingspan of 56–69 cm, and a weight 450–650 g.

Distribution and ecology

This species breeds in the northern taiga of Europe and the Palearctic. 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 (for example, at Dungeness), mostly at regular sites. Vagrants have been recorded in North America. On lakes it prefers areas around the edges, often under small trees. The smew breeds in May and lays 7–11 cream-colored eggs, incubated by the female for 26–28 days. Ducklings leave the nest soon after hatching and learn to fly within about 10 weeks.

It nests in tree holes, such as old woodpecker nests. It is a shy bird and flushes easily when disturbed.

The smew is one of the species to which the ''Agreement on the Conservation of African-Eurasian Migratory Waterbirds'' (AEWA) applies. It is not considered threatened on the IUCN Red List, though its population is decreasing.

Fossil history

Subfossils from this species are also found in the Early Pleistocene of West Runton, England indicate that the living species' range extended there a few thousand years ago.

Gallery

File:Smew RWD1.jpg , Male
File:Smew female RWD5.jpg, Female
File:Smew from the Crossley ID Guide Britain and Ireland.jpg, ID composite
Mergellus albellus MHNT.ZOO.2010.11.33.1.jpg, ''Mergellus albellus'' - MHNT

References

External links

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{{Taxonbar, from=Q200646

Mergansers
Birds of Europe
Birds of Russia
Birds of North Asia
Birds described in 1758
Taxa named by Carl Linnaeus