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The Nauru reed warbler ((ナウル語:itsirir)), ''Acrocephalus rehsei'', is a passerine bird endemic to the island of Nauru in the Pacific Ocean. It is one of only two native breeding land-birds on Nauru, the other being the Micronesian pigeon, and it is the only passerine found on the island. It is related to other Micronesian reed warblers, all of which evolved from one of several radiations of the genus across the Pacific. Related warblers on nearby islands include the Carolinian reed warbler, with which the Nauru species was initially confused, and the nightingale reed warbler, which was formerly sometimes considered the same species. A medium-sized warbler, the Nauru reed warbler has dark brown upperparts, cream underparts and a long, thin beak. It makes a low, cup-shaped nest into which it lays two or three white eggs, and it feeds on insects. However, details about its behavior and ecology are little known. It is found throughout Nauru, which has changed substantially in recent decades due to phosphate mining. The Nauru reed warbler is potentially threatened by introduced predators and habitat loss, and its small range means that it could be vulnerable to chance occurrences, such as tropical cyclones. Reports of a similar warbler from nearby islands suggest that it might previously have been found elsewhere, but was driven to local extinction by introduced cats. ==Taxonomy and systematics== Otto Finsch was the first naturalist to visit the island of Nauru, stopping for six hours on 24 July 1880 while travelling from the Marshall Islands to the Solomon Islands. His 1881 report included a warbler he initially identified as the Carolinian reed warbler. By 1883 he considered it to be a new species, ''Calamoherpe rehsei''.〔Buden 2008a, p. 8.〕 The generic name ''Calamoherpe'' is now recognised as a synonym of ''Acrocephalus'',〔Jobling 2010, p. 84.〕 leading to the current binomial name. The generic name ''Acrocephalus'' derives from the Greek ''akros'', meaning "topmost", and ''kephale'', meaning "head". The ''akros'' part of the name may have been given through confusion with ''acutus'', and taken to mean "sharp-pointed", referring to the angular head shape typical of this genus.〔Jobling 2010, pp. 30–31.〕 The synonym ''Calamoherpe'' is from the Greek ''kalamos'', meaning "reed", and ''herpes'', meaning "creeping thing".〔 Finsch named the species after Ernst Rehse, a German ornithologist and collector and one of Finsch's travelling companions.〔Finsch 1883, p. 142.〕〔Jobling 2010, p. 332.〕 Since the original descriptions, little has been written about the species,〔Buden 2008a, p. 16.〕 and details about its ecology and behaviour are poorly known.〔 Though the Nauru reed warbler is generally accepted as a species, some authorities, such as H. E. Wolters in ''Die Vogelarte der Erde'' (1980) and Howard and Moore in ''A Complete Checklist of the Birds of the World'' (1991), have considered it a subspecies of ''Acrocephalus luscinius'', the nightingale reed warbler. Recent DNA studies have affirmed its status as a separate species.〔 It is considered monotypic, meaning there are no recognised subspecies.〔 The species is known by the English common names Finsch's reed-warbler, Nauru warbler, pleasant warbler, the Nauru reed-warbler, and the Nauru reed warbler.〔 In the native Nauruan language, it is known as ''Itsirir''.〔 A 2009 phylogenic study of the family Acrocephalidae did not include this species, and as recently as 2010 its relation with other members of the genus was unknown.〔 A 2011 analysis of mitochondrial DNA showed that the Nauru reed warbler forms a clade with the Australian reed warbler, the bokikokiko, the southern Marquesan reed warbler and a now-extinct species from Pagan Island in the Marianas. The closest relative of the Nauru reed warbler appears to be the extinct warbler from Pagan. This is currently named as a subspecies of the nightingale reed warbler, ''A. luscinius yamashinae'', but that species is polyphyletic, and the Pagan form, which has been proposed as a new species, the Pagan reed warbler, is in a different clade to nightingale reed warblers from other islands.〔 The pattern of colonisation of the Pacific islands and eventually Australia by the ''Acrocephalus'' warblers from Asia was complex, with multiple colonisations of even remote archipelagos. Although the Hawaiian islands were colonised about 2.3 million years ago, the other islands were reached much more recently, in the mid-Pleistocene (between 0.2–1.4 million years ago) or even later. The nearest other warblers geographically to Nauru are the Carolinian reed warbler and the nightingale reed warbler.〔〔Spenneman 2006, p. 258.〕 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「Nauru reed warbler」の詳細全文を読む スポンサード リンク
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