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The little raven (''Corvus mellori'') is a species of the family Corvidae that is native to southeastern Australia. An adult individual is about 48–50 cm (19–20 in) in length, with all-black plumage, beak and legs and a white iris, as do the other members of the genus ''Corvus'' in Australia and some species from the islands to the north. Like those of the other two species of raven in Australia, its black feathers have grey bases. Although the little raven was first named by Gregory Mathews in 1912, it was only in 1967 that there was consensus to separate it from the Australian raven (''C. coronoides'') as a distinct species. ==Taxonomy== In the 1960s, the CSIRO were intensively studying Australian raven populations and their relationship to lambing and sheep in southeastern Australia. It became evident that there was a smaller species of raven living alongside the Australian raven. These birds lived in smaller trees, had smaller throat hackles and lacked the bare skin of their larger relative. They were also nomadic and made different calls. Ian Rowley investigated old scientific names assigned to type specimens and concluded that they matched ''Corvus mellori'' as described by Gregory Mathews in 1912. The type specimen was collected from Angas Plains in South Australia in 1901. It disappeared in transit in 1966. The little raven is closely related to the other four species of Australian corvid, which include the Torresian crow and little crow as well as the forest raven and Australian raven. Initial single gene genetic analysis of the genus using mitochondrial DNA showed the three raven species to belong to one lineage and the two crows to another. The genetic separation between species is small and there was a suggestion the little raven may be nested within the Australian raven, though the authors conceded more genetic work was needed. Subsequent multigene analysis using nuclear DNA by Jønsson and colleagues in 2012 showed the forest and little raven are each other's closest relatives, with the Australian raven an earlier offshoot. Rowley proposed that the common ancestor of the five species diverged into a tropical crow and temperate raven sometime after entering Australia from the north. The raven diverged into the ancestor of the forest and little ravens in the east and Australian raven in the west. As the climate was cooler and dryer, the aridity of central Australia split them entirely. Furthermore, the eastern diverged into nomadic little ravens as the climate became dryer and, in forested refuges, forest ravens. As the climate eventually became warmer, the western ravens spread eastwards and outcompeted forest ravens on mainland Australia but coexisted with little ravens. Rowley proposed the name "little raven" for the new species, conceding it was generic but noting it was demonstrative, and that "little crow" had been adopted over "Bennett's crow" for ''Corvus bennettii''.〔 The term "crow" is colloquially applied to any or all species of Australian corvid.〔 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「little raven」の詳細全文を読む スポンサード リンク
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