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Tadorna
The shelducks, most species of which are found in the genus ''Tadorna'' (except for the Radjah shelduck, which is now found in its own monotypic genus ''Radjah''), are a group of large birds in the Tadorninae subfamily of the Anatidae, the biological family that includes the ducks and most duck-like waterfowl such as the geese and swans. Biology Shelducks are a group of large, often semi-terrestrial waterfowl, which can be seen as intermediate between geese (''Anserinae'') and ducks. They are mid-sized (some 50–60 cm) Old World waterfowl. The sexes are colored slightly differently in most species, and all have a characteristic upperwing coloration in flight: the tertiary remiges form a green speculum, the secondaries and primaries are black, and the coverts (forewing) are white. Their diet consists of small shore animals ( winkles, crabs etc.) as well as grasses and other plants. They were originally known as "sheldrakes", which remained the most common name until the late ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Common Shelduck
The common shelduck (''Tadorna tadorna'') is a waterfowl species of the shelduck genus, ''Tadorna''. It is widespread and common in the Euro-Siberian region of the Palearctic, mainly breeding in temperate and wintering in subtropical regions; in winter, it can also be found in the Maghreb. Fossil bones from Dorkovo (Bulgaria) described as ''Balcanas pliocaenica'' may actually belong to this species. More likely, they are an extinct species of ''Tadorna'' (if not a distinct genus) due to their Early Pliocene age; the present species is not unequivocally attested from the fossil record until some 2–3 million years later (Late Pliocene/ Early Pleistocene). Taxonomy The common shelduck was formally named by the Swedish naturalist Carl Linnaeus in 1758 in the tenth edition of his '' Systema Naturae'' under the binomial name ''Anas tadorna''. Linnaeus largely based his description on "The Sheldrake or Burrough-Duck" that had been described and illustrated in 1731 by the English ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Common Shelduck
The common shelduck (''Tadorna tadorna'') is a waterfowl species of the shelduck genus, ''Tadorna''. It is widespread and common in the Euro-Siberian region of the Palearctic, mainly breeding in temperate and wintering in subtropical regions; in winter, it can also be found in the Maghreb. Fossil bones from Dorkovo (Bulgaria) described as ''Balcanas pliocaenica'' may actually belong to this species. More likely, they are an extinct species of ''Tadorna'' (if not a distinct genus) due to their Early Pliocene age; the present species is not unequivocally attested from the fossil record until some 2–3 million years later (Late Pliocene/ Early Pleistocene). Taxonomy The common shelduck was formally named by the Swedish naturalist Carl Linnaeus in 1758 in the tenth edition of his '' Systema Naturae'' under the binomial name ''Anas tadorna''. Linnaeus largely based his description on "The Sheldrake or Burrough-Duck" that had been described and illustrated in 1731 by the English ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radjah Shelduck
The radjah shelduck (''Radjah radjah''), is a species of shelduck found mostly in New Guinea and Australia, and also on some of the Moluccas. It is known alternatively as the raja shelduck, black-backed shelduck, or in Australia as the Burdekin duck. Taxonomy The specific name ''radjah '' is from the Moluccan name ''Radja'' for the radjah shelduck on the island of Buru in Indonesia. Formerly placed in the genus ''Tadorna'', it differs markedly from other members in external morphology and mtDNA cytochrome ''b'' sequence data, suggesting its status should be reinvestigated.Sraml, M.; Christidis, L.; Easteal, S.; Horn, P. & Collet, C. (1996): Molecular Relationships Within Australasian Waterfowl (Anseriformes). ''Australian Journal of Zoology'' 44(1): 47–58. Current classification places it in its own monotypic genus ''Radjah''. Description Both the male and female of the species are mostly white, with dark wing-tips and a distinctive "collar" of dark feathers. Seen from ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anatidae
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. (The magpie goose is no longer considered to be part of the Anatidae and is now placed in its own family, Anseranatidae.) They are generally herbivorous, and are monogamous breeders. A number of species undertake annual migrations. A few species have been domesticated for agriculture, and many others are hunted for food and recreation. Five species have become extinct since 1600, and many more are threatened with extinction. Description and ecology The ducks, geese, and swans are small- to large-sized birds with a broad and elongated general body plan. Diving species vary from this in being rounder. Extant s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Egyptian Goose
The Egyptian goose (''Alopochen aegyptiaca'') is a member of the duck, goose, and swan family Anatidae. It is native to Africa south of the Sahara and the Nile Valley. Egyptian geese were considered sacred by the Ancient Egyptians, and appeared in much of their artwork. Because of their popularity chiefly as an ornamental bird, escapees are common and feral populations have become established in Western Europe, the United States, and New Zealand. Taxonomy The Egyptian goose is believed to be most closely related to the shelducks (genus ''Tadorna'') and their relatives, and is placed with them in the subfamily Tadorninae. It is the only extant member of the genus ''Alopochen'', which also contains closely related prehistoric and recently extinct species. mtDNA cytochrome ''b'' sequence data suggest that the relationships of ''Alopochen'' to ''Tadorna'' need further investigation. Etymology The generic name ''Alopochen'' (literally, ''fox-goose'') is based on Greek (''alōpós ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Waterfowl
Anseriformes is an order of birds also known as waterfowl that comprises about 180 living species of birds in three families: Anhimidae (three species of screamers), Anseranatidae (the magpie goose), 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. Evolution Anseriformes are one of only two types of modern bird to be confirmed present during the Mesozoic alongside the other dinosaurs, and in fact were among the very few birds to survive their extinction, along with their cousins the galliformes. These two groups only occupied two ecological niches during the Mesozoic, living in water and on the ground, while the toothed enantiornithes were the dominant bird ... [...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] |
Alopochen
''Alopochen'' is a genus of the bird family Anatidae, part of the subfamily Tadorninae along with the shelducks. It contains one extant species, the Egyptian goose (''Alopochen aegyptiaca''), and two or three species which became extinct in the last 1000 years or so. The Egyptian goose is native to mainland Africa, and the extinct species are from Madagascar and the Mascarene Islands. mtDNA cytochrome ''b'' sequence data suggest that the relationships of ''Alopochen'' to ''Tadorna'' need further investigation. Species * Egyptian goose, ''Alopochen aegyptiaca'' The extinct species of the genus are: * Malagasy shelduck or Madagascar shelduck, ''Alopochen sirabensis'' (Andrews 1897) (may be subspecies of ''A. mauritiana'') – Madagascar, prehistoric: see Late Quaternary prehistoric birds * Mauritius sheldgoose, ''Alopochen mauritiana'' (Newton & Gadow 1893)– Mauritius, late 1690s * Réunion sheldgoose or Kervazo's Egyptian goose, ''Alopochen kervazoi'' (Cowles 1994) Mourer-Ch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monophyletic
In cladistics for a group of organisms, monophyly is the condition of being a clade—that is, a group of taxa composed only of a common ancestor (or more precisely an ancestral population) and all of its lineal descendants. Monophyletic groups are typically characterised by shared derived characteristics ( synapomorphies), which distinguish organisms in the clade from other organisms. An equivalent term is holophyly. The word "mono-phyly" means "one-tribe" in Greek. Monophyly is contrasted with paraphyly and polyphyly as shown in the second diagram. A ''paraphyletic group'' consists of all of the descendants of a common ancestor minus one or more monophyletic groups. A '' polyphyletic group'' is characterized by convergent features or habits of scientific interest (for example, night-active primates, fruit trees, aquatic insects). The features by which a polyphyletic group is differentiated from others are not inherited from a common ancestor. These definitions have tak ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Canvasback
The canvasback (''Aythya valisineria'') is a species of diving duck, the largest found in North America. Taxonomy Scottish-American naturalist Alexander Wilson described the canvasback in 1814. The genus name is derived from Greek ''aithuia'', an unidentified seabird mentioned by authors, including Hesychius and Aristotle. The species name ''valisineria'' comes from the wild celery ''Vallisneria americana'', whose winter buds and rhizomes are the canvasback's preferred food during the nonbreeding period. The celery genus is itself named for seventeenth century Italian botanist Antonio Vallisneri. The duck's common name is based on early European inhabitants of North America's assertion that its back was a canvas-like color. In other languages it is just a ''white-backed duck''; for example in French, ''morillon à dos blanc'', or Spanish, ''pato lomo blanco''. In Mexico it is called ''pato coacoxtle''. Description It ranges from in length and weighs , with a wingspan of . ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MtDNA
Mitochondrial DNA (mtDNA or mDNA) is the DNA located in mitochondria, cellular organelles within eukaryotic cells that convert chemical energy from food into a form that cells can use, such as adenosine triphosphate (ATP). Mitochondrial DNA is only a small portion of the DNA in a eukaryotic cell; most of the DNA can be found in the cell nucleus and, in plants and algae, also in plastids such as chloroplasts. Human mitochondrial DNA was the first significant part of the human genome to be sequenced. This sequencing revealed that the human mtDNA includes 16,569 base pairs and encodes 13 proteins. Since animal mtDNA evolves faster than nuclear genetic markers, it represents a mainstay of phylogenetics and evolutionary biology. It also permits an examination of the relatedness of populations, and so has become important in anthropology and biogeography. Origin Nuclear and mitochondrial DNA are thought to be of separate evolutionary origin, with the mtDNA being derived from t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Madagascar
Madagascar (; mg, Madagasikara, ), officially the Republic of Madagascar ( mg, Repoblikan'i Madagasikara, links=no, ; french: République de Madagascar), is an island country in the Indian Ocean, approximately off the coast of East Africa across the Mozambique Channel. At Madagascar is the world's List of island countries, second-largest island country, after Indonesia. The nation is home to around 30 million inhabitants and consists of the island of Geography of Madagascar, Madagascar (the List of islands by area, fourth-largest island in the world), along with numerous smaller peripheral islands. Following the prehistoric breakup of the supercontinent Gondwana, Madagascar split from the Indian subcontinent around 90 million years ago, allowing native plants and animals to evolve in relative isolation. Consequently, Madagascar is a biodiversity hotspot; over 90% of wildlife of Madagascar, its wildlife is endemic. Human settlement of Madagascar occurred during or befo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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