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Aix (genus)
''Aix'' is a bird genus that contains two species of ducks: the wood duck (''Aix sponsa''), and the Mandarin duck (''Aix galericulata''). ''Aix'' is an Ancient Greek word used by Aristotle to refer to an unknown diving bird. Taxonomy The genus belongs to the family Anatidae in the waterfowl order Anseriformes. They were formerly placed in the "perching ducks", a paraphyletic group somewhat intermediate between shelducks and dabbling ducks, and it is not quite clear whether they should be placed in the Anatinae (dabbling duck) or Tadorninae (shelduck) subfamily. Extant species Habitat Both species migrate from the northern parts of their respective ranges to winter in the south of the range. They inhabit quiet wooded streams and ponds. Description The two species are generally considered to be very attractive, particularly the multi-coloured drakes. The genus shows marked sexual dimorphism (differences between the sexes), with the females being smaller and less colorful. D ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wood Duck
The wood duck or Carolina duck (''Aix sponsa'') is a species of perching duck found in North America. The drake wood duck is one of the most colorful North American waterfowl. Description The wood duck is a medium-sized perching duck. A typical adult is from ( or 1.5 feet max.) In length with a wingspan of between . The wood duck's weight ranges from 454-862 g (16.0-30.4 oz). This is about three-quarters of the length of an adult mallard. It shares its genus with the Asian Mandarin duck (''Aix galericulata''). The adult male has stunning multicolored iridescent plumage and red eyes, with a distinctive white flare down the neck. The female, less colorful, has a white eye-ring and a whitish throat. Both adults have crested heads. The male's call is a rising whistle, ''jeeeeee''; the females utter a drawn-out, rising squeal, ''do weep do weep'', when flushed, and a sharp ''cr-r-ek, cr-e-ek'' for an alarm call. Behavior Their breeding habitat is wooded swamps, shallow l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perching Duck
The term perching ducks is used colloquially to mean any species of ducks distinguished by their readiness to perch high in trees Until the late 20th century, perching ducks meant ''Cairinini'', a tribe of ducks in the duck, goose and swan family Anatidae, grouped together on the basis of their readiness to perch high in trees. It has been subsequently shown that the grouping is paraphyletic and their apparent similarity results from convergent evolution, with the different members more closely related to various other ducks than to each other. Perching duck species include: Plectropterinae *Spur-winged goose ''Plectropterus gambensis'' Tadorninae *Salvadori's teal ''Salvadorina waigiuensis'' (initially placed in Anatinae) *Blue duck ''Hymenolaimus malacorhynchos'' *Torrent duck ''Merganetta armata'' Anatinae *Brazilian teal ''Amazonetta brasiliensis'' Species that were formally in the Cairdinini tribe, and do not have an identified current subfamily include: *Comb duck ''S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territories, nine Minor Outlying Islands, and 326 Indian reservations. The United States is also in free association with three Pacific Island sovereign states: the Federated States of Micronesia, the Marshall Islands, and the Republic of Palau. It is the world's third-largest country by both land and total area. It shares land borders with Canada to its north and with Mexico to its south and has maritime borders with the Bahamas, Cuba, Russia, and other nations. With a population of over 333 million, it is the most populous country in the Americas and the third most populous in the world. The national capital of the United States is Washington, D.C. and its most populous city and principal financial center is New York City. Paleo-Americ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States Geological Survey
The United States Geological Survey (USGS), formerly simply known as the Geological Survey, is a scientific agency of the United States government. The scientists of the USGS study the landscape of the United States, its natural resources, and the natural hazards that threaten it. The organization's work spans the disciplines of biology, geography, geology, and hydrology. The USGS is a fact-finding research organization with no regulatory responsibility. The agency was founded on March 3, 1879. The USGS is a bureau of the United States Department of the Interior; it is that department's sole scientific agency. The USGS employs approximately 8,670 people and is headquartered in Reston, Virginia. The USGS also has major offices near Lakewood, Colorado, at the Denver Federal Center, and Menlo Park, California. The current motto of the USGS, in use since August 1997, is "science for a changing world". The agency's previous slogan, adopted on the occasion of its hundredt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
North America
North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Caribbean Sea, and to the west and south by the Pacific Ocean. Because it is on the North American Plate, North American Tectonic Plate, Greenland is included as a part of North America geographically. North America covers an area of about , about 16.5% of Earth's land area and about 4.8% of its total surface. North America is the third-largest continent by area, following Asia and Africa, and the list of continents and continental subregions by population, fourth by population after Asia, Africa, and Europe. In 2013, its population was estimated at nearly 579 million people in List of sovereign states and dependent territories in North America, 23 independent states, or about 7.5% of the world's population. In Americas (terminology)#Human ge ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Helm Identification Guides
The ''Helm Identification Guides'' are a series of books that identify groups of birds. The series include two types of guides, those that are: * Taxonomic, dealing with a particular family of birds on a worldwide scale—most early Helm Guides were this type, as well as many more-recent ones, although some later books deal with identification of such groups on a regional scale only (e.g., ''The Gulls Guide,'' which covers only species in Europe, Asia, and North America) * Geographic, including all bird species in an area (e.g., ''The Birds of the West Indies'') Early volumes were sometimes published under the Croom Helm or Christopher Helm imprints. In addition, a parallel set of guides, very similar in design, was published by Pica Press in the 1990s (marked ''Pica'' in the list below); Pica was later absorbed into A & C Black (now part of Bloomsbury Publishing Plc), and all guides are now marketed as a single series. Several of the books have won the British Birds ''Bird B ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Portable Document Format
Portable Document Format (PDF), standardized as ISO 32000, is a file format developed by Adobe in 1992 to present documents, including text formatting and images, in a manner independent of application software, hardware, and operating systems.Adobe Systems IncorporatedPDF Reference, Sixth edition, version 1.23 (53 MB) Nov 2006, p. 33. Archiv/ref> Based on the PostScript language, each PDF file encapsulates a complete description of a fixed-layout flat document, including the text, fonts, vector graphics, raster images and other information needed to display it. PDF has its roots in "The Camelot Project" initiated by Adobe co-founder John Warnock in 1991. PDF was standardized as ISO 32000 in 2008. The last edition as ISO 32000-2:2020 was published in December 2020. PDF files may contain a variety of content besides flat text and graphics including logical structuring elements, interactive elements such as annotations and form-fields, layers, rich media (including video con ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Auk (journal)
''Ornithology'', formerly ''The Auk'' and ''The Auk: Ornithological Advances'', is a peer-reviewed scientific journal and the official publication of the American Ornithological Society (AOS). It was established in 1884 and is published quarterly. The journal covers the anatomy, behavior, and distribution of birds. It was named for the great auk, the symbol of the AOS. In 2018, the American Ornithology Society announced a partnership with Oxford University Press to publish ''The Auk: Ornithological Advances'' and '' The Condor: Ornithological Applications'' ''.'' In January 2021, the journal was renamed ''Ornithology'', with the stated goal of improving descriptiveness, thematic focus, and ease of citation of the journal title. The society's sister publication '' The Condor'' was renamed ''Ornithological Applications'' at the same time. Editors The following have been editors-in-chief of the journal: See also * List of ornithology journals References External links ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subfamily
In biological classification, a subfamily (Latin: ', plural ') is an auxiliary (intermediate) taxonomic rank, next below family but more inclusive than genus. Standard nomenclature rules end subfamily botanical names with "-oideae", and zoological names with "-inae". See also * International Code of Nomenclature for algae, fungi, and plants * International Code of Zoological Nomenclature * Rank (botany) * Rank (zoology) In biological classification, taxonomic rank is the relative level of a group of organisms (a taxon) in an ancestral or hereditary hierarchy. A common system consists of species, genus, family, order, class, phylum, kingdom, domain. While ... Sources {{biology-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tadorninae
The Tadorninae is the shelduck-sheldgoose subfamily of the Anatidae, the biological family that includes the ducks and most duck-like waterfowl such as the geese and swans. This group is largely tropical or Southern Hemisphere in distribution, with only two species, the common shelduck and the ruddy shelduck breeding in northern temperate regions, though the crested shelduck (presumed extinct) was also a northern species. Most of these species have a distinctive plumage, but there is no pattern as to whether the sexes are alike, even within a single genus. Systematics Following the review of Livezey (1986), several species formerly classified as aberrant dabbling ducks or as "perching ducks" were placed in the Tadorninae. mtDNA sequence analyses cast doubt on the allocation of several genera; many supposed dabbling ducks and one peculiar goose may more correctly belong here, while some genera believed to be close to shelducks appear to have different relationships altogether ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anatinae
The Anatinae are a subfamily of the family Anatidae (swans, geese and ducks). 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. There has been much debate about the systematical status and which ducks belong to the Anatinae. Some taxonomic authorities only include the dabbling ducks and their close relatives, the extinct moa-nalos. Alternatively, the Anatinae are considered to include most "ducks", and the dabbling ducks form a tribe Anatini within these. The classification as presented here more appropriately reflects the remaining uncertainty about the interrelationships of the major lineages of Anatidae (waterfowl). Systematics The dabbling duck group, of worldwide distribution, was delimited in a 1986 study to include eight genera and some 50–60 living species. However, Salvadori's teal is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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