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The scarlet ibis (''Eudocimus ruber'') is a species of ibis in the bird family Threskiornithidae. It inhabits tropical South America and islands of the Caribbean. In form it resembles most of the other twenty-seven extant species of ibis, but its remarkably brilliant scarlet coloration makes it unmistakable. This medium-sized wader is a hardy, numerous, and prolific bird, and it has protected status around the world. Its IUCN status is Least Concern. The legitimacy of ''Eudocimus ruber'' as a biological classification, however, is in dispute. Traditional Linnaean taxonomy classifies it as a unique species, but an increasing number of scientists have moved to reclassify it as a subspecies of a more general American ibis species, along with its close relative ''Eudocimus albus''. ==Taxonomy== The species was first classified in 1758. Initially given the binomial nomenclature of ''Scolopax rubra''〔 (the name incorporates the Latin adjective ''ruber'', "red"), the species was later designated ''Guara rubra'' and ultimately ''Eudocimus ruber''. Biologically the scarlet ibis is very closely related to the American white ibis (''Eudocimus albus'') and is sometimes considered conspecific with it, leaving modern science divided over their taxonomy. The two birds each have exactly the same bones, claws, beaks, feather arrangements and other features – their one marked difference lies in their pigmentation. Traditional taxonomy has regarded the two as separate and distinct.〔 Early ornithological field research revealed no natural crossbreeding among the red and white, lending support to the two-species viewpoint.〔 More recent observation, however, has documented significant crossbreeding and hybridization in the wild. Researchers Cristina Ramo and Benjamin Busto found evidence of interbreeding in a population where the ranges of the scarlet and white ibises overlap along the coast and in the Llanos in Colombia and Venezuela. They observed individuals of the two species mating and pairing, as well as hybrid ibises with pale orange plumage, or white plumage with occasional orange feathers, and have proposed that these birds be classified as a single species.〔 Hybridization has been known to occur frequently in captivity. However, the two color forms persist in the wild despite overlapping ranges and hybrid offspring having a distinctive color type, so according to the cohesion species concept they would be functionally different species. Some biologists now wish to pair them with ''Eudocimus albus'' as two subspecies of the same American ibis.〔 Others simply define both of them as one and the same species, with ''ruber'' being a color variation of ''albus''. 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「scarlet ibis」の詳細全文を読む スポンサード リンク
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