1960 年 10 巻 4 号 p. 148-153
This paper forms a part of the studies reported in the'Miscellaneous Reports'of the Yamashina Museum of Birds. The summer roosts(including partly winter) of the grey starling and their feeding ranges in the city zone and western plains of Tokyo Prefecture were investigated chiefly in 1958〜59. The winter feeding habitat is almost exclusively the wet rice paddies of the north (Saitama Pref.) and very few of them are found on upland fields and in the city of Tokyo. In summer, the grown rice fields become unfit for feeding and the starling population increases in the city zone where there are abundant berries of the cherry (many cherry avenues), Morus, Elaeagnus, Machilus, etc. Also there is a rich insect fauna on the lawns of parks and gardens, where they find big old trees with available nesting holes. In the suburbs their distribution is local to the suitable nesting and feeding places. Subject to such movement of the flock, their summer roosts are rather concentrated to the periphery of the city zone (Fig. 1). They use them from May or June. The flock size is largest in July to August and they begin to scatter from October to finally abandon them in middle November. In the suburbs the roosts were few and these are partly used also in winter. In all, eleven roosts, mostly of 2000〜4000 birds, have so far been found within the habitat of the grey starling in Tokyo Prefecture. The counts of five roosts of city periphery indicate that at least 15,000 starlings are concentrated in the southeastern part in summer, while the populstion represented by three widely apart roosts of extensive suburbs is very low.