Smew

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Image:Smew.JPG

Common Name: Smew
Scientific Name: Mergellus albellus

Size: 15-17 inches (38-44 cm); Wingspan: 30 inches (77 cm)

Habitat: Eurasia; breeds in the northern taiga of Europe and Asia. 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. Vagrants have been recorded in North America.

This species is highly migratory, often resting and feeding on inland water bodies when on passage. It arrives on the breeding grounds from April or early-May and breeds from mid-May onwards in single pairs or loose groups. Males gather in large flocks close to the breeding grounds after mating to undergo a flightless molting period. The species then leaves the breeding grounds in early-September and October. Outside of the breeding season the species is highly gregarious and occurs in small or large flocks usually not exceeding 100 individuals, although larger gatherings may form at major passage waters during migration and flocks of over 10,000 have been recorded during the winter.

Preferred breeding habitats are on freshwater, oligotrophic lakes, pools, oxbow lakes, backwaters of large slow-flowing rivers, bogs and flooded riverside woods in coniferous and mixed deciduous or evergreen forest. They show a preference for shallow water and require mature broadleaved trees with holes in which to nest. The species overwinters on large freshwater lakes and reservoirs, ice-free, brackish coastal lagoons, estuaries and sheltered coastal bays (although rarely on the open sea), often resting and feeding on small bodies of water or small streams when on migration.

Status: Least Concern. Global population: 130,000 adult individuals. The population is decreasing and is suspected to be much affected by availability of nest sites in suitable habitat. Populations are also subject to hunting pressure during migration and have been affected by pollution from oil spills. Populations declined in Europe throughout the 19th and 20th centuries due to habitat degradation and loss (e.g. the loss of mature trees in river valleys as a result of logging, conversion to agriculture and building of river canals). The species has also suffered local declines as a result of predation by American mink (Neovison vison) and is susceptible to avian influenza so may be threatened by future outbreaks of the virus.

The Smew is one of the species to which the Agreement on the Conservation of African-Eurasian Migratory Waterbirds (AEWA) applies.

Diet: Aquatic invertebrates (such as adult and larval insects), crustaceans, mollusks and polycheate worms, amphibians, fish and plant matter (such as seeds, leaves and roots) during breeding season. During the winter and in early spring, however, the species mainly feeds on fish. The species feeds diurnally by diving to depths of 1-4 m and forms gregarious nocturnal roosts.

Nesting: The drake Smew, with its panda-like 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.

It has oval white wing-patches in flight. The Smew's bill has a hooked tip.

The species nests in tree hollows up to 10 m or more above the ground and may use those excavated by Black Woodpeckers (Dryocopus martius) in mature broadleaved trees (e.g. oak, willow or aspen). It may also nest in artificial nest boxes, especially those erected to attract Common Goldeneye (Bucephala clangula). It lays 6–9 cream-colored eggs.

Cool Facts: It is the only member of the genus Mergellus and a seaduck fossil from the Middle Miocene shows that birds similar to Smew existed up to 13 million years ago (the extant species dates back to the Pleistocene).

Found in Songbird Remix Waterfowl Volume II: Diving and Sea Ducks

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