Mergini

Sea ducks
Harlequin duck,Histrionicus histrionicus(male)
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Aves
Order:	Anseriformes
Family:	Anatidae
Subfamily:	Anatinae
Tribe:	Mergini Rafinesque,1815
Genera
Clangula Histrionicus Polysticta †Camptorhynchus Somateria Melanitta Bucephala Mergellus Lophodytes Mergus

Thesea ducks(Mergini) are a tribe of theducksubfamily ofbirds,theAnatinae.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 themergansersandsmew,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 theeclipse plumageduring the late summer and molt into their breeding plumage during the winter.

Species

There are twenty-two species in tengenera:

• GenusClangula
  • Long-tailed duck(formerlyoldsquaw) (Clangula hyemalis)
• GenusHistrionicus
  • Harlequin duck(Histrionicus histrionicus)
• Genus †Camptorhynchus
  • †Labrador duck(Camptorhynchus labradorius) (extinct)
• GenusPolysticta
  • Steller's eider(Polysticta stelleri)
• GenusSomateria,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(Somateria spectabilis)
• GenusMelanitta,the scoters. These are stocky marine ducks. The drakes are mostly black and have swollen bills. Females are brown.
  • Common scoter(Melanitta nigra)
  • Black scoterorAmerican scoter(Melanitta americana) (sometimes considered asubspeciesofM. nigra)
  • Velvet scoter(Melanitta fusca)
  • White-winged scoter(Melanitta deglandi) (sometimes considered a subspecies ofM. fusca)
  • Stejneger's scoter(Melanitta stejnegeri)
  • Surf scoter(Melanitta perspicillata)
• GenusBucephala,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(Bucephala albeola)
• GenusMergellus(sometimes included inMergus)
  • Smew(Mergellus albellus)
• GenusLophodytes(sometimes included inMergus)
  • Hooded merganser(Lophodytes cucullatus)
• GenusMergus,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 merganserorgoosander(Mergus merganser)
  • Brazilian merganser(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"Chendyteslawi.

Mergini	Clangula hyemalis Histrionicus histrionicus Polysticta stelleri †Camptorhynchus labradorius Somateria fischeri Somateria mollissima Somateria spectabilis Melanitta nigra Melanitta deglandi Melanitta perspicillata Bucephala albeola Bucephala clangula Bucephala islandica Mergellus albellus Mergus serrator Lophodytes cucullatus Mergus merganser Mergus octosetaceus Mergus squamatus

References

• SeaDucks.org - Science and Management Reference