Abstract
1. Daytime feeding dispersion, roosting activities and their correlations in Emberiza rustica (a winter visitor) and E. cioides (a resident), wintering in the same area, were comparatively studied in footzone to lowland in central Honshu.
2. During the daytime, E. cioides is found dispersed over alluvial dry area. Its sedentary population shows a strong site attachment living in pairs, while those which come down to winter from mountain slopes form small groups, which may be male groups or mixed flocks.
They spend the daytime along the edges of rice paddies. The roosts are formed by small groups in grass patches. The sedentary members form small communal roosts at the edges of rice paddies and those from mountain slopes return to their roosts up in the slopes.
3. E. rustica concentrates in a big flock on rice paddies or gathering at adjoining parts. However, some are dispersed by pairs. The roosts are formed concentrated within a roosting area of a diameter of about 1km in woodland slopes. Thus, they form a definite local population and a local population consisted of about seven hundred birds.
They roost in bushy or grassy patches dispersed in small groups. From about an hour before sunset, they return to the roosting area by singles or in small parties from the daytime feeding grounds on paddy fields, taking a fixed course of roosting flights.
4. The daytime dispersal of E. cioides and E. rustica is environmentally segregated and their behavior patterns and flock size are different. In the night dispersal, E. cioides roosts widely scattered over slopes and paddy fields, while E. rustica concentrates in a certain roosting area in the mountain slope.
5. E. spodocephala shows winter dispersal and migration patterns intermadiate between E. cioides and E. rustica. However, although there are specific different patterns in maintenance of pair units, site adherence, flock size and roosting assemblies in their wintering populations, they are of relative and quantitative differences, and rather represent a general common Emberiza pattern, versus flocking and roosting behaviors of finches or other groups of birds.
