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Steamer Duck
The steamer ducks are a genus (''Tachyeres'') of ducks in the family Anatidae. All of the four species occur at the southern cone of South America in Chile and Argentina, and all except the flying steamer duck are flightless; even this one species capable of flight rarely takes to the air. They can be aggressive and are capable of chasing off predators like petrels. Bloody battles of steamer ducks with each other over territory disputes are observed in nature. They even kill waterbirds that are several times their size. Taxonomy The genus ''Tachyeres'' was introduced in 1875 by the English zoologist Richard Owen to accommodate the Falkland steamer duck. The genus name ''Tachyeres'', "having fast oars" or "fast rower", comes from Ancient Greek ταχυ- "fast" + ἐρέσσω "I row (as with oars)". The common name "steamer ducks" arose because, when swimming fast, they flap their wings into the water as well as using their feet, creating an effect like a paddle steamer. They are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Falkland Steamer Duck
The Falkland steamer duck (''Tachyeres brachypterus'') is a species of flightless duck found on the Falkland Islands in the South Atlantic Ocean. The steamer ducks get their name from their unconventional swimming behaviour in which they flap their wings and feet on the water in a motion reminiscent of an old paddle steamer. The Falkland steamer duck is one of only two bird species endemic to the Falkland Islands, the other being Cobb's wren. Taxonomy and systematics The Falkland steamer duck is part of the Anseriformes order and the Anatidae family alongside ducks, geese, and swans. It is in the genus ''Tachyeres'' with the three other species of steamer ducks, all found in South America. The Falkland steamer duck is most closely related to the flying steamer duck which can also be found in and around the Falkland Islands. It is believed that they might still be able to interbreed. A study from 2012 established that these two species are genetically indistinguishable. Howeve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shelduck
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] |
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] |
Bronze-winged Duck
The bronze-winged duck (''Speculanas specularis'') also known as the spectacled duck, is a dabbling duck and the sole member of its genus ''Speculanas''. It is often placed in ''Anas'' with most other dabbling ducks, but its closest relative is either the crested duck or the Brazilian duck, which likewise form monotypic genera. Together they belong to a South American lineage which diverged early from the other dabbling ducks and may include the steamer ducks. Named after the "bronze" speculum this species is also known as "pato perro" or "dog-duck" after the harsh barking call of the female. The bronze-winged duck lives among forested rivers and fast-flowing streams on the lower slopes of the South American Andes, in central and southern Chile and adjacent parts of Argentina. The sexes are alike. As noted by Johnsgard (2010): "Most observers agree that heavily forested rivers that are relatively swift-flowing are the preferred habitat of this species, although they also occu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crested Duck
The crested duck or South American crested duck (''Lophonetta specularioides'') is a species of duck native to South America, the belonging to the monotypic genus ''Lophonetta''. It is sometimes included in ''Anas'', but it belongs to a South American clade that diverged early in dabbling duck evolution. There are two subspecies: ''L. specularioides alticola'' (Andean crested duck) and ''L. specularioides specularioides'' (Patagonian crested duck). The Patagonian crested duck is also called the southern crested duck and its range lies in the Falklands, Chile, and Argentina. Description The crested duck is a medium-sized waterfowl species, with adult males reaching up to just over a kilogram. Males and females look similar, with males having a slightly more prominent crest than females. The feathers of the mantle, back and scapulars are dark brown with pale centers, giving a mottled appearance. The abdomen, flanks and tail coverts are light gray, with the tail itself being dist ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brazilian Duck
The Brazilian teal or Brazilian duck (''Amazonetta brasiliensis'') is the only duck in the genus ''Amazonetta''. It is widely distributed in eastern South America. Taxonomy The Brazilian teal was formally described in 1789 by the German naturalist Johann Friedrich Gmelin in his revised and expanded edition of Carl Linnaeus's ''Systema Naturae''. He placed it with all the other ducks, swans and geese in the genus ''Anas'' and coined the binomial name ''Anas brasiliensis''. Gmelin based his description on the ''Mareca alia species'' (the second Mareca) that was described in 1648 by the German naturalist Georg Marcgrave in his ''Historia Naturalis Brasiliae''. The Brazilian teal is now the only species placed in the genus ''Amazonetta'' that was introduced by the German zoologist Hans von Boetticher in 1929. It was formerly considered a '' perching duck'', but more recent analyses indicate that it belongs to a clade of South American dabbling ducks which also includes the crested ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dabbling Duck
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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clade
A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English term, the equivalent Latin term ''cladus'' (plural ''cladi'') is often used in taxonomical literature. The common ancestor may be an individual, a population, or a species (extinct or extant). Clades are nested, one in another, as each branch in turn splits into smaller branches. These splits reflect evolutionary history as populations diverged and evolved independently. Clades are termed monophyletic (Greek: "one clan") groups. Over the last few decades, the cladistic approach has revolutionized biological classification and revealed surprising evolutionary relationships among organisms. Increasingly, taxonomists try to avoid naming taxa that are not clades; that is, taxa that are not monophyletic. Some of the relationships between organisms ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genes
In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a basic unit of heredity and the molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protein-coding genes and noncoding genes. During gene expression, the DNA is first copied into RNA. The RNA can be directly functional or be the intermediate template for a protein that performs a function. The transmission of genes to an organism's offspring is the basis of the inheritance of phenotypic traits. These genes make up different DNA sequences called genotypes. Genotypes along with environmental and developmental factors determine what the phenotypes will be. Most biological traits are under the influence of polygenes (many different genes) as well as gen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protein Subunit
In structural biology, a protein subunit is a polypeptide chain or single protein molecule that assembles (or "''coassembles''") with others to form a protein complex. Large assemblies of proteins such as viruses often use a small number of types of protein subunits as building blocks. A subunit is often named with a Greek or Roman letter, and the numbers of this type of subunit in a protein is indicated by a subscript. For example, ATP synthase has a type of subunit called α. Three of these are present in the ATP synthase molecule, leading to the designation α3. Larger groups of subunits can also be specified, like α3β3-hexamer and c-ring. Naturally-occurring proteins that have a relatively small number of subunits are referred to as oligomeric.Quote: ''Oligomer molecule: A molecule of intermediate relative molecular mass, the structure of which essentially comprises a small plurality of units derived, actually or conceptually, from molecules of lower relative molecular ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NADH Dehydrogenase
NADH dehydrogenase is an enzyme that converts nicotinamide adenine dinucleotide (NAD) from its reduced form (NADH) to its oxidized form (NAD+). Members of the NADH dehydrogenase family and analogues are commonly systematically named using the format ''NADH:acceptor oxidoreductase''. The chemical reaction these enzymes catalyze are generally represented with the follow equation; : NADH + H+ + acceptor NAD+ + reduced acceptor NADH dehydrogenase is a flavoprotein that contains iron-sulfur centers. NADH dehydrogenase is used in the electron transport chain for generation of ATP. The EC term NADH dehydrogenase (quinone) (EC 1.6.5.11) is defined for NADH dehydrogenases that use a quinone (excluding ubiquinone) as the acceptor. The EC term NADH dehydrogenase (ubiquinone) Respiratory complex I, (also known as NADH:ubiquinone oxidoreductase, Type I NADH dehydrogenase and mitochondrial complex I) is the first large protein complex of the respiratory chains of many organisms from bac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cytochrome B
Cytochrome b within both molecular and cell biology, is a protein found in the mitochondria of eukaryotic cells. It functions as part of the electron transport chain and is the main subunit of transmembrane cytochrome bc1 and b6f complexes. Function In the mitochondrion of eukaryotes 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 an analogous 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 Cytochrome b/b6 is an integral membrane protein of approximately 400 amino acid residues that probably has 8 transmembrane segments. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
