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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 lat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ruddy Shelduck
The ruddy shelduck (''Tadorna ferruginea''), known in India as the Brahminy duck, is a bird species in the family Anatidae. It is a distinctive waterfowl, in length with a wingspan of . It has orange-brown body plumage with a paler head, while the tail and the flight feathers in the wings are black, contrasting with the white wing-coverts. It is a migratory bird, wintering in the Indian subcontinent and breeding in southeastern Europe and central Asia, though there are small resident populations in North Africa. It has a loud honking call. The ruddy shelduck mostly inhabits inland water-bodies such as lakes, reservoirs and rivers. The male and female form a lasting pair bond and the nest may be well away from water, in a crevice or hole in a cliff, tree or similar site. A clutch of about eight eggs is laid and is incubated solely by the female for about four weeks. The young are cared for by both parents and fledge about eight weeks after hatching. In central and eastern As ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Common Shelduck
The common shelduck (''Tadorna tadorna'') is a waterfowl species of the shelduck genus, ''shelduck, Tadorna''. It is widespread and common in the Euro-Siberian region of the Palearctic realm, 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 Species description, formally named by the Swedish naturalist Carl Linnaeus in 1758 in the 10th edition of Systema Naturae, tenth edition of his ''Systema Naturae'' under the binomial nomenclature, binomial name ''Anas tadorna''. Linnaeus largely based his description o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anatidae
The Anatidae are the biological family (biology), family of water birds that includes ducks, goose, geese, and swans. The family has a cosmopolitan distribution, occurring on all the world's continents except Antarctica. These birds are adapted for aquatic locomotion, swimming, floating on the water surface, and, in some cases, diving in at least shallow water. The family contains around 174 species in 43 genus, 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 monogamy in animals, monogamous breeders. A number of species undertake bird migration, 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 elo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tadorninae
The Tadornini is a biological tribe that includes the shelducks and sheldgeese, which is placed in subfamily Anatinae of family Anatinae, which includes the ducks and most duck-like waterfowl such as the geese and swans. It has been treated as subfamily in the past. 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 Tadornini. mtDNA sequence analyses cast doubt on the allocation of several genera; many supposed dabbling ducks and one peculiar goose may more correctly belong here, wh ... [...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, the clade consisting of all other modern birds except the galliformes and paleognaths. 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, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Egyptian Goose
The Egyptian goose (''Alopochen aegyptiaca'') is an African member of the Anatidae family including ducks, geese, and swans. Because of their popularity chiefly as an ornamental bird, the species has also been introduced to Europe, the United States and elsewhere outside their natural range. Egyptian geese were regularly represented in ancient Egyptian art. Taxonomy The Egyptian goose was formally described in 1766 by the Swedish naturalist Carl Linnaeus in the twelfth edition of his ''Systema Naturae'' under the binomial name ''Anas aegyptiaca''. Linnaeus partly based his account on the "L'oye d'Egypte" that had been described and illustrated in 1760 by the French ornithologist Mathurin Jacques Brisson in his ''Ornithologie''. Brisson used the Latin name ''Anser Egyptiatiacus'' but although he coined Latin names for species, these do not conform to the binomial system and are not recognised by the International Commission on Zoological Nomenclature. The Egyptian goose ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alopochen
''Alopochen'' is a genus of the bird family (biology), family Anatidae, part of the subfamily Tadorninae along with the shelducks. It contains one extant species, the Egyptian goose (''Alopochen aegyptiaca''), and three which became extinct in the last 1,000 years or so. The Egyptian goose is native to mainland Africa, and the recently extinct species are from Madagascar and the Mascarene Islands. mtDNA cytochrome b, cytochrome ''b'' DNA sequence, 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 a subspecies of ''A. mauritiana'') – Madagascar, Late Pleistocene: see Late Quaternary prehistoric birds * †Mauritius sheldgoose (''Alopochen mauritiana'') (Newton & Gadow 1893) – Mauritius, late 1690s * †Réunion sheldgoose or Kervazo's Eg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
English Language
English is a West Germanic language that developed in early medieval England and has since become a English as a lingua franca, global lingua franca. The namesake of the language is the Angles (tribe), Angles, one of the Germanic peoples that Anglo-Saxon settlement of Britain, migrated to Britain after its End of Roman rule in Britain, Roman occupiers left. English is the list of languages by total number of speakers, most spoken language in the world, primarily due to the global influences of the former British Empire (succeeded by the Commonwealth of Nations) and the United States. English is the list of languages by number of native speakers, third-most spoken native language, after Mandarin Chinese and Spanish language, Spanish; it is also the most widely learned second language in the world, with more second-language speakers than native speakers. English is either the official language or one of the official languages in list of countries and territories where English ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paraphyletic
Paraphyly is a taxonomic term describing a grouping that consists of the grouping's last common ancestor and some but not all of its descendant lineages. The grouping is said to be paraphyletic ''with respect to'' the excluded subgroups. In contrast, a monophyletic grouping (a clade) includes a common ancestor and ''all'' of its descendants. The terms are commonly used in phylogenetics (a subfield of biology) and in the tree model of historical linguistics. Paraphyletic groups are identified by a combination of synapomorphies and symplesiomorphies. If many subgroups are missing from the named group, it is said to be polyparaphyletic. The term received currency during the debates of the 1960s and 1970s accompanying the rise of cladistics, having been coined by zoologist Willi Hennig to apply to well-known taxa like Reptilia (reptiles), which is paraphyletic with respect to birds. Reptilia contains the last common ancestor of reptiles and all descendants of that ancestor exc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DNA Sequence
A nucleic acid sequence is a succession of bases within the nucleotides forming alleles within a DNA (using GACT) or RNA (GACU) molecule. This succession is denoted by a series of a set of five different letters that indicate the order of the nucleotides. By convention, sequences are usually presented from the 5' end to the 3' end. For DNA, with its double helix, there are two possible directions for the notated sequence; of these two, the sense strand is used. Because nucleic acids are normally linear (unbranched) polymers, specifying the sequence is equivalent to defining the covalent structure of the entire molecule. For this reason, the nucleic acid sequence is also termed the primary structure. The sequence represents genetic information. Biological deoxyribonucleic acid represents the information which directs the functions of an organism. Nucleic acids also have a secondary structure and tertiary structure. Primary structure is sometimes mistakenly referred to as "prim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cytochrome B
Cytochrome b is a protein found in the membranes of aerobic cells. In eukaryotic mitochondria (inner membrane) and in aerobic prokaryotes, cytochrome b is a component of respiratory chain complex III () — also known as the bc1 complex or ubiquinol-cytochrome c reductase. In plant chloroplasts and cyanobacteria, there is a homologous protein, cytochrome b6, a component of the plastoquinone-plastocyanin reductase (), also known as the b6f complex. These complexes are involved in electron transport, the pumping of protons to create a proton-motive force ( PMF). This proton gradient is used for the generation of ATP. These complexes play a vital role in cells. Structure and function Cytochrome b/b6 is an integral membrane protein of approximately 400 amino acid residues that probably has 8 transmembrane segments. In plants and cyanobacteria, cytochrome b6 consists of two protein subunits encoded by the petB and petD genes. Cytochrome b/b6 non-covalently binds two heme ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
