Measurements and Identification of the Japanese Northern Goshawk Accipiter gentilis fujiyamae
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- Shigeta Yoshimitsu
- Bird Migration Research Center, Yamashina Institute for Ornithology
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- Momose Hiroshi
- Landscape and Ecology Division, National Institute for Land and Infrastructure Management, Ministory of Land, Infrastructure and Transport
Bibliographic Information
- Other Title
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- 日本産オオタカAccipiter gentilis fujiyamaeの測定値と識別
- ニホンサン オオタカ Accipiter gentilis fujiyamae ノ ソクテイチ ト シキベツ
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Abstract
The subspecies fujiyamae of Northern Goshawk Accipiter gentilis breeds in Japan, Sakhalin, and Southern Kurile Islands as an endemic subspecies (OSJ 2000). This paper shows the measurements from 64 individuals of A. g. fujiyamae caught in central Saitama and southeastern Tochigi Prefectures, Honshu, along with the identification criteria of sex and age based upon measurements (Table 1), plumage features (Fig.1), and iris colour (Table 2). Adult males were significantly smaller than adult females for all measurements (Table 1). Tails of juveniles were significantly longer than adult tails for males (t-test, t=2.238, df=26, P<0.05) and probably also for females (Table 1). We could distinguish the age as juvenile, first winter, and adult plumages based on the plumages combined with iris colour (Fig.1). A few juvenile feathers of upper and under wing-coverts remained in first winter plumage until about two years old, which was the bird's third year. Measurements from live birds tended to be larger than the data reported in the literature, which were mostly taken from specimens. The difference was as large as 10 mm in the case of tarsus length. The iris was pale yellow (sulfur yellow) in juvenile plumage and tended to acquire an orange tinge as the bird aged, mainly spectrum yellow or orange yellow in first winter plumage, and orange yellow or orange in adult plumage after in the second winter plumage. We show for the first time that the iris may turn red for old males of Japanese Northern Goshawks A. g. fujiyamae (Table 2 and Fig. 1).
Journal
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- Journal of the Yamashina Institute for Ornithology
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Journal of the Yamashina Institute for Ornithology 38 (1), 22-29, 2006
Yamashina Institute for Ornitology
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Details 詳細情報について
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- CRID
- 1390001205224112512
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- NII Article ID
- 130000446344
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- NII Book ID
- AA11864856
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- ISSN
- 18820999
- 13485032
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- NDL BIB ID
- 8527523
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- Text Lang
- ja
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- Data Source
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- JaLC
- NDL
- Crossref
- CiNii Articles
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- Abstract License Flag
- Disallowed