The sea ducks (''Mergini'') are a tribe of the

duck Duck is the common name for numerous species of waterfowl in the family Anatidae. Ducks are generally smaller and shorter-necked than swans and geese, which are members of the same family. Divided among several subfamilies, they are a fo ...

subfamily of

bird Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweig ...

s, the Anatinae. The taxonomy of this group is incomplete. Some authorities separate the group as a subfamily, while others remove some genera. Most species within the group spend their winters near coastal waters. Many species have developed specialized salt glands to allow them to tolerate salt water, but these are poorly developed in juveniles. Some of the species prefer riverine habitats. All but two of the 22 species in this group live in far northern latitudes. The fish-eating members of this group, such as the mergansers and smew, have serrated edges to their bills to help them grip their prey and are often known as "sawbills". Other sea ducks forage by diving underwater, taking molluscs or crustaceans from the sea floor. The Mergini take on the eclipse plumage during the late summer and molt into their breeding plumage during the winter.

Species

There are twenty-two species in ten

genera Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial ...

: *Genus ''

Clangula The long-tailed duck (''Clangula hyemalis''), formerly known as oldsquaw, is a medium-sized sea duck that breeds in the tundra and taiga regions of the arctic and winters along the northern coastlines of the Atlantic and Pacific Oceans. It is t ...

'' **

Long-tailed duck The long-tailed duck (''Clangula hyemalis''), formerly known as oldsquaw, is a medium-sized sea duck that breeds in the tundra and taiga regions of the arctic and winters along the northern coastlines of the Atlantic and Pacific Oceans. It is t ...

(formerly oldsquaw) (''Clangula hyemalis'') *Genus ''

Histrionicus The harlequin duck (''Histrionicus histrionicus'') is a small sea duck. It takes its name from Harlequin (French ''Arlequin'', Italian ''Arlecchino''), a colourfully dressed character in Commedia dell'arte. The species name comes from the La ...

'' ** Harlequin duck (''Histrionicus histrionicus'') *Genus †''

Camptorhynchus The Labrador duck (''Camptorhynchus labradorius'') was a North American bird; it has the distinction of being the first known endemic North American bird species to become extinct after the Columbian Exchange, with the last known sighting occurr ...

'' ** † Labrador duck (''Camptorhynchus labradorius'') ( extinct) *Genus ''

Polysticta Steller's eider (''Polysticta stelleri'') is a migrating Arctic diving duck that breeds along the coastlines of eastern Russia and Alaska. It is the rarest, smallest, and fastest flying of the eider species. Amongst the Inupiat, Steller's eider is ...

'' ** Steller's eider (''Polysticta stelleri'') *Genus '' Somateria'', the eiders. These are large marine ducks. The drakes have body plumage showing varying amounts of black and white, and distinctive head patterns. Females are brown. ** Spectacled eider (''Somateria fischeri'') ** Common eider (''Somateria mollissima'') **

King eider The king eider (pronounced ) (''Somateria spectabilis'') is a large sea duck that breeds along Northern Hemisphere Arctic coasts of northeast Europe, North America and Asia. The birds spend most of the year in coastal marine ecosystems at high l ...

(''Somateria spectabilis'') *Genus ''

Melanitta The scoters are stocky seaducks in the genus ''Melanitta''. The drakes are mostly black and have swollen bills, the females are brown. They breed in the far north of Europe, Asia, and North America, and winter farther south in temperate zones of ...

'', the scoters. These are stocky marine ducks. The drakes are mostly black and have swollen bills. Females are brown. ** Common scoter (''Melanitta nigra'') ** Black scoter or American scoter (''Melanitta americana'') (sometimes considered a subspecies of ''M. nigra'') **

Velvet scoter The velvet scoter (''Melanitta fusca''), also called a velvet duck,Buczacki, Stefan (2005) ''Fauna Britannica'', Hamlyn, London. is a large sea duck, which breeds over the far north of Europe and the Palearctic west of the Yenisey basin. The gen ...

(''Melanitta fusca'') **

White-winged scoter The white-winged scoter (''Melanitta deglandi'') is a large sea duck. The genus name is derived from Ancient Greek ''melas'' "black" and ''netta'' "duck". The species name commemorates French ornithologist Côme Damien Degland. Description The ...

(''Melanitta deglandi'') (sometimes considered a subspecies of ''M. fusca'') ** Surf scoter (''Melanitta perspicillata'') *Genus '' Bucephala'', the goldeneyes. These are less marine than some species in this group, and will winter on fresh water. Drakes have white bodies with black backs and distinctive head markings. Females are grey with chestnut heads. ** Common goldeneye (''Bucephala clangula'') ** Barrow's goldeneye (''Bucephala islandica'') **

Bufflehead The bufflehead (''Bucephala albeola'') is a small sea duck of the genus ''Bucephala'', the goldeneyes. This species was first described by Carl Linnaeus in his landmark 1758 10th edition of ''Systema Naturae'' as ''Anas albeola''. The genus n ...

(''Bucephala albeola'') *Genus '' Mergellus'' (sometimes included in ''Mergus'') ** Smew (''Mergellus albellus'') *Genus '' Lophodytes'' (sometimes included in ''Mergus'') ** Hooded merganser (''Lophodytes cucullatus'') *Genus '' Mergus'', the typical mergansers. These are the least marine of this group, only red-breasted and common mergansers being common on the sea. These are large saw-billed ducks which dive for fish. ** Red-breasted merganser (''Mergus serrator'') ** † New Zealand merganser (''Mergus australis'') ** Common merganser or goosander (''Mergus merganser'') **

Brazilian merganser The Brazilian merganser (''Mergus octosetaceus'') is a South American diving duck in the Mergus genus. It is one of the six most threatened waterfowl in the world, with possibly fewer than 250 birds in the wild and a few kept in captivity ...

(''Mergus octosetaceus'') ** Scaly-sided merganser (''Mergus squamatus'') Below is a phylogeny based on a mitogenomic study of the placement of the Labrador duck and the diving "goose" '' Chendytes lawi''.

References

SeaDucks.org - Science and Management Reference
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