山階鳥類学雑誌
Online ISSN : 1882-0999
Print ISSN : 1348-5032
ISSN-L : 1348-5032
研究ノート
同一巣内で確認されたニホンイヌワシ Aquila chrysaetos japonica の雛2羽とその巣立ち
小澤 俊樹
著者情報
ジャーナル 認証あり

2025 年 57 巻 2 号 p. 142-150

詳細
抄録

The Golden Eagle Aquila chrysaetos is a raptor that inhabits mountainous areas. In Japan, the subspecies A. c. japonica is distributed throughout the country, mainly in Honshu. The population of Golden Eagles has been greatly reduced due to lack of food as well as reduction of hunting grounds. Furthermore, their reproductive rate is low. Most Golden Eagles in Japan lay two eggs per clutch; however, the number of chicks that fledge is almost always only one. Instances of two chicks fledging from the same nest are extremely rare, occurring in only 0.8% of successful breeding attempts. In June 2024, the author observed two chicks in a nest, and later confirmed the moment each chick departed the nest. The first chick left the nest at 16:51 on June 4th, and the second chick at 5:58 on June 8th. In addition, the two juvenile birds were observed flying every day during a juvenile bird field observation conducted from June 11th to June 15th. This is the first documented case in Japan where the moment two chicks fledged from the same nest was visually observed and recorded.

著者関連情報
© 2025 公益財団法人 山階鳥類研究所
前の記事 次の記事
feedback
Top