秋田県に渡来したハクガンの長期記録(1971/72年冬〜2010/11年冬)

摘要

By the 1940s, the Snow Goose Anser caerulescens was considered to be extinct in Japan. From 1970 to 1993, it was recorded as an irregular visitor in Honshu, while from 1969 to 1991 twelve geese were recorded in Hokkaido. In 1993, an international project was carried out to restore the Far East population of the Snow Goose. We had monitored the number of Snow Geese at Ogata Reclaimed Land, Akita Prefecture, for 40 winter seasons from 1971/72 to 2010/11. This species had been recorded as an irregular visitor until the 1990/91 season. Since 1993， when the restoration project started, this species has been recorded regularly, and the number of individuals has shown a general increase, reaching 39 individuals in 2010/11. They were observed mainly along the west channel of Hachiro-gata, and 728 foraging sites were recorded in this area.%ハクガンAnser caerulescensは，北アメリカ大陸北部，グリーンランド，シベリア東北部コマリ川下流域やウランゲリ島など北極圏で繁殖し，北アメリカ大陸中部，中国，日本などで越冬する冬鳥である(高野1989)。