Bird Censuses in the Oze Area in Non-breeding Season, 1974-1980

Abstract

The avifauna of Oze area, Gunma Prefecture, in non-breeding season (autumn) was investigated from 1974 to 1980. (See TAKAHASHI et al., 1978, for the avifauna of breeding season.) The line transect method was employed for the estimation of the numbers of species and of individuals. Results obtained are as follows :(1) A total of 76 species was recorded in the autumn months from September to early November when the area was not covered with snow. The avifauna was extremely poor in winter from mid November to early April as the ground was covered with thick snow.(2) In the forests of Oze area Parus ater, Parus montanus, Aegithalos caudatus, Cettia diphone, Turdus naumanni, and Phylloscopus borealis were dominant species in non-breeding season (autumn). Particularly a large number of P. ater, P. montanus, and A. caudatus were recorded.(3) Tits were chief constituents of birds in various forests. The number of individuals of tits occupied 31.2% of the total number of birds observed. P. montanus and A. caudatus appeared to prefer deciduous and P. ater to prefer coniferous forests.(4) Of 76 species recorded, 48 species were residents (dominance 70.0%). The other 28 species (dominance 30.0%) belonged to summer visitors, winter visitors, and transient passages.