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Pittas are a family, Pittidae, of passerine birds mainly found in tropical Asia and Australasia, although a couple of species live in Africa. Pittas are all similar in general structure and habits, and have often been placed in a single genus, although as of 2009 they are now split into three genera, ''Pitta'', ''Erythropitta'' and ''Hydrornis''. The name is derived from the word ''pitta'' in the Telugu language of South India and is a generic local name used for all small birds. Pittas are medium-sized by passerine standards, at in length, and stocky, with strong, longish legs and long feet. They have very short tails and stout, slightly decurved bills. Many, but not all, have brightly coloured plumage. These are fairly terrestrial birds of wet forest floors. They eat snails, insects and similar invertebrate prey. Pittas are mostly solitary and lay up to six eggs in a large spherical nest in a tree or shrub, or sometimes on the ground. Both parents care for the young.〔 Many species of pittas are migratory, and they often end up in unexpected places like house-gardens during migration. A number of species of pitta are threatened with extinction. One of these, the Gurney's pitta, is listed as endangered by the IUCN, a further eight species are listed as vulnerable. The main threat to pittas is habitat loss in the form of rapid deforestation. ==Taxonomy and systematics== Pittas were first described scientifically by Carl Linnaeus in 1766 in his revised 12th edition of the ''Systema Naturae''. He placed the Indian pitta in the crow family and genus ''Corvus''. Ten years later it was placed in the thrush family, due to similarities of morphology and behaviour, before being placed in its own genus, ''Pitta'' in 1816 by Louis Vieillot. Vieillot was also the first to consider the genus a family in its own right.〔 The family's closest relatives have for a long time assumed to be the other suboscine birds, and particularly the Old World broadbills and asities (formerly treated as two families, now either lumped into one or split into four). A 2006 study confirmed that these were the closest relatives of the pittas. The number of pitta genera has varied considerably, ranging from one to as many as nine. In his 1863 work ''A Monograph of the Pittidae'' Daniel Elliot split the pittas into two genera, ''Pitta'' for the species with comparatively long tails and ''Brachyurus'' for the shorter tailed species. Barely two decades later, in 1880/81, John Gould split the family into nine genera, to which he also included the lesser melampitta (''Melampitta''), a species which despite uncertain affinities is now at least no longer considered related to the pittas. Soon afterwards Philip Sclater's ''Catalogue of the Birds of the British Museum'' brought the number back down to three. Modern treatments vary as well. A 1975 checklist included six genera, whereas the 2003 volume of the ''Handbook of the Birds of the World'', which covered the family, placed all the pittas in a single genus.〔 The family was not well studied using modern anatomical or phylogenetic techniques; two studies, in 1987 and 1990, each used only four species, and comparisons amongst the family as a whole have relied mostly on external features and appearances.〔 A 2006 study of the nuclear DNA of the pittas, using study skins from museums, was the first to examine most representatives of the family, and found evidence of three major clades of pitta. Based on the study it proposed splitting the pittas into three genera. The first clade, using the genus name ''Erythropitta'', includes six species that had previously been considered closely related on external features. They are all generally small species with small tails, extensive amounts of crimson or red on the underparts, and greenish or blueish backs. The second genus, ''Hydrornis'', includes a number of variable Oriental species. These species are unified morphologically in exhibiting sexual dimorphism in their plumage, as well as in possessing cryptic juvenile plumage (in all the species thus far studied). Into this second clade is included the eared pitta, which had often been placed into its own genus, ''Anthocincla'', on account of its apparent primitive characteristics. The third genus, ''Pitta'', is the most widespread clade. Most species in this genus have green upperparts with a blue wing-patch, dark upperparts and cinnamon-buff underparts. This clade contains all the migratory species of pitta, and it is thought that many of the pitta species from islands are derived from migratory species.〔 This division of the pittas into three genera has been adopted by the International Ornithological Congress' ''Birds of the World: Recommended English Names''. As with genera, there has been considerable variation in the number of recorded pitta species. The checklists of Sclater and Elliot at the end of the 19th century contained 48 and 47 species each. More recent checklists have had fewer than this, one listing just 24 species. Since the 1990s the figure has been between 30 and 32 species; the ''Handbook of the Birds of the World'' recognises 30. Two potential species not recognised by the Handbook include the black-crowned pitta, which is treated as a subspecies of either the garnet pitta or the graceful pitta, and the Sula pitta, which can be treated as a subspecies of the red-bellied pitta.〔 More recently the banded pitta has been split into three new species, one endemic to Java and Bali, one endemic to Borneo and one found in Sumatra and the Thai-Malay Peninsula. 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「Pitta」の詳細全文を読む スポンサード リンク
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