関東地方における秋期のヒヨドリの渡り‐齋藤（１９３５‐１９４３）の観察記録の解析

DOI Web Site 被引用文献2件 参考文献4件

書誌事項

タイトル別名
  • Autumn Migration of the Brown-eared Bulbul Hypsipetes amaurotis in Kanto District, Japan: Analysis of the Data Recorded by Saito (1935-1943)
  • 関東地方における秋期のヒヨドリの渡り--齋藤(1935-1943)の観察記録の解析
  • カントウ チホウ ニ オケル シュウキ ノ ヒヨドリ ノ ワタリ サイトウ 1935 1943 ノ カンサツ キロク ノ カイセキ
  • Analysis of the Data Recorded by Saito (1935-1943)
  • —齋藤(1935-1943)の観察記録の解析

この論文をさがす

抄録

In the plains of Kanto district, Japan, flocks of the Brown-eared Bulbul Hypsipetes amaurotis often undertake a southern autumn migration. From 1934 to 1942 Mr. Genzaburo Saito made daily observations throughout the annual autumn migrations at Chiba City, Chiba Prefecture, and recorded values of several migration parameters. I analyzed his data to clarify the migration status c. 70 years ago and to assess whether the status differed from the present one. Results showed the annual number of migrating individuals to vary from c. 400 to c. 1,700 with a median of c. 900 and c. 14 individuals in a flock. Flights began in late September and finished in early November, with most flocks flying in October. Comparison with the data of Yamaguchi (2004, 2005) revealed the values obtained at Chiba City c. 70 years ago do not differ greatly from those occurring at the present time. Therefore, even though part of the H. amaurotis population has begun to breed in the plain regions in west-southern districts in Japan over the past 70 years, the migration status has remained unchanged. During each migration period, the number of migrating birds showed at least two peaks. The mean time at which peaks occurred differed between days, suggesting that the site at which each flock had started to fly was respectively different. Flocks arrived from the northwest and departed in a southeasterly direction, and the variance of the direction was very small. As this direction is parallel to the coastline at Chiba City, the birds may fly along the coastline towards the southern part of Boso peninsula where Chiba City is located. However, some flocks may visit forests en route, and remain there for a time. Therefore, autumn migrating flocks of H. amaurotis are thought to show a flexible behaviour responding to environmental conditions.

収録刊行物

  • 山階鳥類学雑誌

    山階鳥類学雑誌 39 (2), 69-86, 2008

    公益財団法人 山階鳥類研究所

被引用文献 (2)*注記

もっと見る

参考文献 (4)*注記

もっと見る

キーワード

詳細情報 詳細情報について

問題の指摘

ページトップへ