北海道の低地におけるホシガラスの越冬
1989 年 38 巻 2 号 p. 104-106
詳細
1989 年 38 巻 2 号 p. 104-106
One to three Nutcrakers Nucifraga caryocatactes were observed in residential areas and wood islands of suburban areas in Obihiro City and its environs, central Hokkaido, from mid-October 1988 to late June 1989. Besides, Nutcrackers were recorded from Hakodate, Sapporo and Furano from October 1988 to mid-June 1989. Poor cone production of the Japanese Stone Pine Pinus pumila in 1988 was considered to be one of causes of their wintering at low altitudes.
