Abstract
1. A series of bird censuses was made during Oct., 1967-Oct. 1968 within 191.9km2 of cultivated farmlands in southern Kanto Plain. In total, 29 censuses, 1-5 times per month, covered 197.2km, 19.76km2 (with an observation width of 100m) and 4, 633 minutes, and 2-15km and 60-260 minutes per census.
2. Random census routes were selected so as to cover rather evenly the total study area.
3. Seasonally, 39 species in spring, 22 in summer, 31 in autumn and 27 in winter were recorded, with 39 species spring to summer and 37 species autumn to winter.
4. The avifauna consisted of 14 resident species, 9 summer visitors, 13 winter visitors and 13 transients, which varied by season.
5. The number of individuals recorded was 3, 456 birds in spring, 2, 662 birds in summer (spring to summer 6, 118 birds) as against 5, 600 birds in autumn, 5, 022 birds in winter (autumn to winter 10, 622 birds), thus showing a great increase of number in winter season. Therefore the study area had environmental value of winterquarter type for the bird community
6. In number of individuals, the resident species far outnumbered other groups occupying 93% (89% in summer and 96% in winter seasons) of the total bird community.
7. Among residents, Passer montanus occupied 47% (45% in summer, 49% in winter), and Sturnus cineraceus 28% (23% in summer, 31% in winter) far more outnumbering others, as compared with next ranked Cyanopica cyana 5%, followed by Streptopelia decaocto 4%, Alauda arvensis 3% and Egretta garzetta 1% then Corvus corone, Lanius bucephalus, Streptopelia orientalis, Chloris sinica, Cisticola juncidis, Corvus macrorhynchos, Phasianus colchicus and Bambusicola thoracica. Among birds of other group, only a few species, Hirundo rustica 10% in summer, Turdus eunomus 2% in winter and Sturnus philippensis 0.5% in late summer showed seasonal perceivable dominance among the bird community.
8. The distributional patterns of the above several main species were plotted on 1/50, 000 scale map of the study area, showing the concentration area, or dispersed pattern and the seasonal change.
