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Aythyini
The diving ducks, commonly called pochards or scaups, are a category of duck which feed by diving beneath the surface of the water. They are part of Anatidae, the diverse and very large family that includes ducks, geese, and swans. The diving ducks are placed in a distinct tribe in the subfamily Anatinae, the Aythyini. While morphologically close to the dabbling ducks, there are nonetheless some pronounced differences such as in the structure of the trachea. mtDNA cytochrome ''b'' and NADH dehydrogenase subunit 2 sequence data indicate that the dabbling and diving ducks are fairly distant from each other, the outward similarities being due to convergent evolution. Alternatively, the diving ducks are placed as a subfamily Aythyinae in a subfamily Anatidae which would encompass all duck-like birds except the whistling-ducks. The seaducks commonly found in coastal areas, such as the long-tailed duck (formerly known in the U.S. as oldsquaw), scoters, goldeneyes, mergansers, buffle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aythya
''Aythya'' is a genus of diving ducks. It has twelve described species. The name ''Aythya'' comes from the Ancient Greek word (), which may have referred to a sea-dwelling duck or an auklet. ''Aythya shihuibas'' was described from the Late Miocene of China. Zelenkov (2016) transferred the species ''Anas denesi'' Kessler (2013), known from the late Miocene of Hungary, to the genus ''Aythya''. An undescribed prehistoric species is known only from Early Pleistocene fossil remains found at Dursunlu, Turkey; it might however be referrable to a paleosubspecies of an extant species considering its age (see also Greater scaup). The Miocene ''"Aythya" arvernensis'' is now placed in '' Mionetta'', while ''"Aythya" chauvirae'' seems to contain the remains of two species, at least one of which does not seem to be a diving duck. The genus ''Aythya'' was introduced in 1822 by the German zoologist Friedrich Boie. The type species is the greater scaup. ''Aythya'' species The genus contains ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Greater Scaup
The greater scaup (''Aythya marila''), just scaup in Europe or, colloquially, "bluebill" in North America, is a mid-sized diving duck, larger than the closely related lesser scaup. It spends the summer months breeding in Alaska, northern Canada, Siberia, and the northernmost reaches of Europe. During the winter, it migrates south to the coasts of North America, Europe, and Japan. Drake greater scaup are larger and have more rounded heads than the females; they have a bright blue bill and yellow eyes. Their heads are dark, with a green gloss; the breast is black, the belly white and the wing shows a white stripe. The females are mostly brown, again with white on the wing. They have dull blue bills and white on the face. Greater scaup nest near water, typically on islands in northern lakes or on floating mats of vegetation. They begin breeding at age two, but start building nests in the first year. The drakes have a complex courtship, which takes place on the return migration to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 form taxon; they do not represent a monophyletic group (the group of all descendants of a single common ancestral species), since swans and geese are not considered ducks. Ducks are mostly aquatic birds, and may be found in both fresh water and sea water. Ducks are sometimes confused with several types of unrelated water birds with similar forms, such as loons or divers, grebes, gallinules and coots. Etymology The word ''duck'' comes from Old English 'diver', a derivative of the verb 'to duck, bend down low as if to get under something, or dive', because of the way many species in the dabbling duck group feed by upending; compare with Dutch and German 'to dive'. This word replaced Old English / 'duck', possibly to avoid confusion with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Convergent Evolution
Convergent evolution is the independent evolution of similar features in species of different periods or epochs in time. Convergent evolution creates analogous structures that have similar form or function but were not present in the last common ancestor of those groups. The cladistic term for the same phenomenon is homoplasy. The recurrent evolution of flight is a classic example, as flying insects, birds, pterosaurs, and bats have independently evolved the useful capacity of flight. Functionally similar features that have arisen through convergent evolution are ''analogous'', whereas '' homologous'' structures or traits have a common origin but can have dissimilar functions. Bird, bat, and pterosaur wings are analogous structures, but their forelimbs are homologous, sharing an ancestral state despite serving different functions. The opposite of convergence is divergent evolution, where related species evolve different traits. Convergent evolution is similar to parallel evo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cosmopolitan Distribution
In biogeography, cosmopolitan distribution is the term for the range of a taxon that extends across all or most of the world in appropriate habitats. Such a taxon, usually a species, is said to exhibit cosmopolitanism or cosmopolitism. The extreme opposite of a cosmopolitan species is an endemic one, being found only in a single geographical location. Qualification The caveat “in appropriate habitat” is used to qualify the term "cosmopolitan distribution", excluding in most instances polar regions, extreme altitudes, oceans, deserts, or small, isolated islands. For example, the housefly is highly cosmopolitan, yet is neither oceanic nor polar in its distribution. Related terms and concepts The term pandemism also is in use, but not all authors are consistent in the sense in which they use the term; some speak of pandemism mainly in referring to diseases and pandemics, and some as a term intermediate between endemism and cosmopolitanism, in effect regarding pandemism as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eider
Eiders () are large seaducks in the genus ''Somateria''. The three extant species all breed in the cooler latitudes of the Northern Hemisphere. The down feathers of eider ducks, and some other ducks and geese, are used to fill pillows and quilts—they have given the name to the type of quilt known as an eiderdown. Taxonomy The genus ''Somateria '' was introduced in 1819 to accommodate the king eider by the English zoologist William Leach in an appendix to John Ross's account of his voyage to look for the Northwest Passage. The name is derived from Ancient Greek : ''sōma'' "body" (stem ''somat-'') and : ''erion'' "wool", referring to eiderdown. Steller's eider (''Polysticta stelleri'') is in a different genus despite its name. Species The genus contains three species. Two undescribed species are known from fossils, one from Middle Oligocene rocks in Kazakhstan and another from the Late Miocene or Early Pliocene The Pliocene ( ; also Pleiocene) is the epoch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 name is derived from ancient Greek ''boukephalos'', "bullheaded", from ''bous'', "bull", and ''kephale'', "head", a reference to the oddly bulbous head shape of the species. The species name ''albeola'' is from Latin ''albus'', "white". The English name is a combination of buffalo and head, again referring to the head shape. This is most noticeable when the male puffs out the feathers on the head, thus greatly increasing the apparent size of the head. Description The bufflehead ranges from long and weighs , with the drakes larger than the females. Averaging and , it rivals the green-winged teal as the smallest American duck. The bufflehead has a wingspan of 21.6 in (55 cm). Adult males are striking black and white, with iridescent green ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Merganser
''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 common merganser (''Mergus merganser'') and red-breasted merganser (''M. serrator'') have broad ranges in the northern hemisphere. The Brazilian merganser (''M. octosetaceus'') is a South American duck, and one of the six most threatened waterfowl in the world, with possibly fewer than 250 birds in the wild. The scaly-sided merganser or "Chinese merganser" (''M. squamatus'') is an endangered species. It lives in temperate East Asia, breeding in the north and wintering in the south. The hooded merganser (''Lophodytes cucullatus'', formerly known as ''Mergus cucullatus'') is not of this genus but is closely related. The other "aberrant" merganser, the smew (''Mergellus albellus''), is phylogenetically closer to goldeneyes (''Bucephala''). Although they are seaduck ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Goldeneye (duck)
''Bucephala'' is a genus of diving ducks found in the Northern Hemisphere. Taxonomy The genus ''Bucephala'' was introduced in 1858 by American naturalist Spencer Baird with the bufflehead as the type species. The genus name is derived from Ancient Greek ''boukephalos'', meaning "bullheaded", from ''bous'' "bull", and ''kephale'', "head", a reference to the crest of the bufflehead making its head look large. The bufflehead was formerly treated as the only member of the genus (sometimes unnecessarily changed to ''Charitonetta'') while the goldeneyes were incorrectly placed in ''Clangula'' (as ''Clangula americana''), the genus of the long-tailed duck, which at that time was placed in ''Harelda''.Report of the National conference on utilization of forest products. New national museum, Washington, DC, November 19 and 20, 1924. Issue 13. US Govt. print. off. 1925. It may yet be correct to recognise two genera, as the bufflehead and the two goldeneyes are well diverged. In this case, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scoter
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 those continents. They form large flocks on suitable coastal waters. These are tightly packed, and the birds tend to take off together. Their lined nests are built on the ground close to the sea, lakes or rivers, in woodland or tundra. These species dive for crustaceans and molluscs. Taxonomy The genus ''Melanitta'' was introduced by the German zoologist Friedrich Boie in 1822. The type species was designated in 1838 as the velvet scoter by Thomas Campbell Eyton. The genus name combines the Ancient Greek ''melas'' meaning "black" and ''netta'' meaning "duck". The genus contains six species: The presumed fossil "scoter" ''Melanitta ceruttii'', which lived in California during the Late Pliocene, is now placed in the genus ''Histrionicus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 the only member of the genus ''Clangula''. Taxonomy The long-tailed duck was formally described by the Swedish naturalist Carl Linnaeus in 1758 in the tenth edition of his ''Systema Naturae''. He placed it with all the other ducks in the genus ''Anas'' and coined the binomial name ''Anas hyemalis''. Linnaeus cited the English naturalist George Edwards's description and illustration of the "Long-tailed duck from Hudson's-Bay" that had been published in 1750 in the third volume of his ''A Natural History of Uncommon Birds''. This duck is now the only species placed in the genus ''Clangula'' that was introduced in 1819 to accommodate the long-tailed duck by the English zoologist William Leach in an appendix to John Ross's account of his vo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seaduck
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. Species There are twenty-two species in ten genera: *Genus ''Clang ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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