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The Galliformes are an order of heavy-bodied ground-feeding birds that includes turkey, grouse, chicken, New World quail and Old World quail, ptarmigan, partridge, pheasant, junglefowl and the Cracidae. The name derives from "gallus", Latin for "cock" or "rooster". Common names are gamefowl or gamebirds, landfowl, gallinaceous birds, or galliforms. "Wildfowl" or just "fowl" are also often used for the Galliformes, but usually these terms also refer to waterfowl (Anseriformes), and occasionally to other commonly hunted birds. This group has about 290 species, one or more of which are found in essentially every part of the world's continents (except for the innermost deserts and perpetual ice). They are rarer on islands, and in contrast to the closely related waterfowl, are essentially absent from oceanic islands—unless introduced there by humans. Several species have been domesticated during their long and extensive relationships with humans. This order contains five families: Phasianidae (including chicken, quail, partridges, pheasants, turkeys, peafowl and grouse), Odontophoridae (New World quails), Numididae (guineafowl), Cracidae (including chachalacas and curassows), and Megapodiidae (incubator birds like mallee fowl and brush-turkeys). They are important as seed dispersers and predators in the ecosystems they inhabit, and are often reared as game birds by humans for their meat and eggs and for recreational hunting. Many gallinaceous species are skilled runners and escape predators by running rather than flying. Males of most species are more colorful than the females. Males often have elaborate courtship behaviors that include strutting, fluffing of tail or head feathers, and vocal sounds. They are mainly nonmigratory. == Systematics and evolution == The living Galliformes were once divided into seven or more families. Despite their distinctive appearance, grouse and turkeys probably do not warrant separation as families due to their recent origin from partridge- or pheasant-like birds. The turkeys became larger after their ancestors colonized temperate and subtropical North America, where pheasant-sized competitors were absent. The ancestors of grouse, though, adapted to harsh climates and could thereby colonize subarctic regions. Consequently, the Phasianidae are expanded in current taxonomy to include the former Tetraonidae and Meleagrididae as subfamilies.〔Kimball ''et al.'' (1999), Dyke et al. (2003), Smith ''et al.'' (2005), Crowe ''et al.'' (2006a,b)〕 The Anseriformes (waterfowl) and the Galliformes together make up the Galloanserae. They are basal among the living neognathous birds, and normally follow the Paleognathae (ratites and tinamous) in modern bird classification systems. This was first proposed in the Sibley-Ahlquist taxonomy and has been the one major change of that proposed scheme that was almost universally adopted. However, the Galliformes as they were traditionally delimited are called Gallomorphae in the Sibley-Ahlquist taxonomy, which splits the Cracidae and Megapodiidae as an order "Craciformes". This is not a natural group, however, but rather an erroneous result of the now-obsolete phenetic methodology employed in the Sibley-Ahlquist taxonomy.〔Smith ''et al.'' (2005), Crowe ''et al.'' (2006a,b)〕 Phenetic studies do not distinguish between plesiomorphic and apomorphic characters, which leads to basal lineages appearing as monophyletic groups. Historically, the buttonquails (Turnicidae), mesites (Mesitornithidae) and the hoatzin (''Opisthocomus hoazin'') were placed in the Galliformes, too. The former are now known to be shorebirds adapted to an inland lifestyle, whereas the mesites are probably closely related to pigeons and doves. The relationships of the hoatzin are entirely obscure, and it is usually treated as a monotypic order Opisthocomiformes to signify this. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Galliformes」の詳細全文を読む スポンサード リンク
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