カラスの就塒行動について : 第I報 長野県下での秋冬の塒について
1962 年 12 巻 2 号 p. 54-59
詳細
1962 年 12 巻 2 号 p. 54-59
YAMAGISHI, Satoshi (Tenryu Low. Sec. School, Nagano Pref.) Roosting behaviour in crows. 1. Autumnal and wintry roosting behaviour in Nagano Prefecture. Jap. J. Ecol. 12,54〜59 (1962) The roosting behaviour of crows was observed in Nagano Prefecture, and the results are as follows : (1) In the daytime in autumn crows form small flocks in their habitat and feed there. Before sunset they gather at their regular assembling places, and then move to roost in groups. The group at the farthest assembling place from the roost move first, joining the nearest group, one by one, and at last all of the crows reach the roost. (Fig. 1) (2) There are three roosts in autumn in Upper Ina-gun and Lower Ina-gun ; in winter one of these three is used as their wintry roost, and the other two are canelled, being used only as their assembling places. Crows' number in each of these three autumnal roosts is about 900,and the number in one wintry roost is about 3,000. (Fig. 2) (3) The numbers of the above-mentioned wintry roosts are seven in Nagano Prefecture ; crows' number in each of them is 1,000〜3,000. Only ever-green woods are used as the wintry roosts, the main tree species of which is Japanese red-pine. (Fig. 3,Table 1) (4) In the future I intend to investigate on crows' roost in their breeding season and the actual organization of their society.
