1982 年 14 巻 2-3 号 p. 206-213
Bird populations were censused by the spot-mapping method in the natural mixed forest in Asahikawa, central Hokkaido, during breeding seasons of 1975 and 1976. Fifty species of birds were recorded during the study. Of these 31 species had stationary home ranges and the other 19 species were visitors in the study plot of 25ha. The total number of pairs for all species was 120.0 in 1975 and 125.0 in 1976. The dominant and subdominant species were Erithacus cyane, Cettia squameiceps, Phylloscopus occipitalis, Regulus regulus, Ficedula narcissina, Parus palustris, P. ater, P. major and Emberiza spodocephala. These 9 species accounted for 70% of the numbers of pairs for all species. The type of bird community structure was similar to that of the natural mixed forest described by Kuroda.