Sea ducks | |
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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 |
The sea ducks (Mergini) are a tribe of the duck subfamily of birds, 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.
There are twenty-two species in ten genera:
Below is a phylogeny based on a mitogenomic study of the placement of the Labrador duck and the diving "goose" Chendytes lawi. [1]
Mergini | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
The Labrador duck is an extinct North American duck. 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 occurring in 1878 in Elmira, New York. It was already a rare duck before European settlers arrived, and as a result of its rarity, information on the Labrador duck is not abundant, although some, such as its habitat, characteristics, dietary habits and reasons behind its extinction, are known. There are 55 specimens of the Labrador duck preserved in museum collections worldwide.
The Anatidae are the biological family of water birds that includes ducks, geese, and swans. The family has a cosmopolitan distribution, occurring on all the world's continents except Antarctica. These birds are adapted for swimming, floating on the water surface, and in some cases diving in at least shallow water. The family contains around 174 species in 43 genera.
Anseriformes is an order of birds also known as waterfowl that comprises about 180 living species of birds in three families: Anhimidae, Anseranatidae, and Anatidae, the largest family, which includes over 170 species of waterfowl, among them the ducks, geese, and swans. Most modern species in the order are highly adapted for an aquatic existence at the water surface. With the exception of screamers, males have penises, a trait that has been lost in the Neoaves. Due to their aquatic nature, most species are web-footed.
The smew 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.
The Anatinae are a subfamily of the family Anatidae. Its surviving members are the dabbling ducks, which feed mainly at the surface rather than by diving. The other members of the Anatinae are the extinct moa-nalo, a young but highly apomorphic lineage derived from the dabbling ducks.
Mergus is the genus of the typical mergansers fish-eating ducks in the subfamily Anatinae. The genus name is a Latin word used by Pliny the Elder and other Roman authors to refer to an unspecified waterbird.
The surf scoter is a large sea duck native to North America. Adult males are almost entirely black with characteristic white patches on the forehead and the nape and adult females are slightly smaller and browner. Surf scoters breed in Northern Canada and Alaska and winter along the Pacific and Atlantic coasts of North America. Those diving ducks mainly feed on benthic invertebrates, mussels representing an important part of their diet.
Chendytes lawi is an extinct, goose-sized flightless marine duck, once common on the California coast, the California Channel Islands, and possibly southern Oregon. It lived in the Pleistocene and survived into the Holocene. It appears to have gone extinct at about 450–250 BCE. The youngest direct radiocarbon date from a Chendytes bone fragment dates to 770–400 BCE and was found in an archeological site in Ventura County. Its remains have been found in fossil deposits and in early coastal archeological sites. Archeological data from coastal California show a record of human exploitation of Chendytes lawi for at least 8,000 years. It was probably driven to extinction by hunting, animal predation, and loss of habitat. Chendytes bones have been identified in archaeological assemblages from 14 coastal sites, including two on San Miguel Island and 12 in mainland localities. Hundreds of Chendytes bones and egg shells found in Pleistocene deposits on San Miguel Island have been interpreted as evidence that some of these island fossil localities were nesting colonies, one of which Guthrie dated to about 12,000 14C years. There is nothing in the North American archaeological record indicating a span of exploitation for any megafaunal genus remotely as long as that of Chendytes.
The boreal forest or taiga of the North American continent stretches through a majority of Canada and most of central Alaska, extending spottily into the beginning of the Rocky Mountain range in Northern Montana and into New England and the Adirondack Mountains of New York. This habitat extends as far north as the tree line and discontinues in mixed deciduous-coniferous forests to the south. The "taiga", as it is called there, of Eurasia occupies a similar range on those continents. Throughout the Northern Hemisphere, the boreal forest covers 2.3 million square miles, a larger area than the remaining Brazilian Amazon rain forest. Although it is largely forest, the boreal forests include a network of lakes, river valleys, wetlands, peat lands and semi-open tundra.