著者

今野 怜 今野 美和 佐藤 文男

出版者

公益財団法人 山階鳥類研究所

雑誌

山階鳥類学雑誌 (ISSN:13485032)

巻号頁・発行日

vol.50, no.1, pp.1-27, 2018-08-31 (Released:2019-08-31)

参考文献数

24

被引用文献数

1

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To facilitate the accurate description of plumage of the Short-tailed Albatross Phoebastria albatrus, we classified plumage into eight components, based on photos taken at a breeding colony on Torishima, Izu Islands. Plumage components of 20 individuals just before fledging and 729 individuals of known sex and ranging in age from 2 to 26 years were scored. The plumage color became more whitish with age. The underbody plumage became white earlier than the upper body, whereas on the thigh, tibia and a posterior part of undertail coverts, dark brown feathers remained even in older age. The upper body turned white from the uppertail coverts towards the front, whereas dark brown feathers remained on the mantle, scapulars and nape, even in older age. The upperwing and underwing were often the same score. The progress of the score was earlier for males than for females. At every age from 3 to 18 years, the summed score of seven components (the underwing score was excluded) was significantly different between sexes, although older age males and females could be considered to have the same score. Individuals with a dark brown mantle, scapulars, rump and uppertail coverts were of age of 5 or less years and had not yet bred, except for a few females. Many individuals started breeding after they had a white part on the rump and uppertail coverts. Males reached final plumage pattern at the age of 8 to 15 years, while females reached final plumage pattern at the age of 11 to 20 years or older.

著者

今野 怜 今野 美和

出版者

日本鳥類標識協会

雑誌

日本鳥類標識協会誌 (ISSN:09144307)

巻号頁・発行日

vol.32, no.1_2, pp.21-35, 2020-12-31 (Released:2021-10-01)

参考文献数

17

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マミチャジナイTurdus obscurus 29個体,シロハラT. pallidus 39個体,アカハラT. chrysolaus 79個体,アカコッコT. celaenops 16個体の翼式の要素(初列風切最長羽,p9の位置,初列風切の間隙,外弁欠刻)を比較した.4種の各要素は有意に異なっており,渡る距離が長い種ほど翼の形状が尖っていた.初列風切の間隙の見た目はマミチャジナイ・アカコッコとシロハラ・アカハラに大別された.アカコッコは間隙を形成する羽毛が独特で外弁欠刻はより近位にあると推察されたこと,マミチャジナイの外弁欠刻はより遠位にあったこととあわせ,翼式は4種の識別に有効であった.