1. During 14-21, June, 1968, the habitat preference, home range and interspecific relations of four species of the genus Emberiza were investigated at Ishikari-Hutomi, Hokkaido.
2. The four species studied and their population densities were: E. schoeniclus, 1.6 bds/ha, E. aureola, 0.6 bds/ha, E. fucata, 0.5 bds/ha and E. spodocephala, 0.2 bds/ha.
3. The habitat had the following five types of vegetation: Sasa, Miscanthus, Phragmites, Myrica and bush. E. schoeniclus had the widest habitat tolerance except for bush-type vegetation, whereas the habitats of E. aureola, E. fucata and E. spodocephala tended to be confined to the areas of Sasa, mixed Sasa-Miscanthus and bush types respectively.
4. E. schoeniclus nested in the mixed Sasa-Miscanthus type and the feeding ground included Phragmites type with a tendency to form an oval-shaped home range extended toward reed bed. The singing area was around the nesting site and the song-post was selected on a stem of tall grass in most cases. Some nests were concentrated to form a loose colony with distances of about 20m. Such a colony was located near a wide reed bed where it used as feeding ground. A pair and also a bird of the same pair tended to have separate, and therefore not common, feeding grounds.
5. The home range of H. aureola was very large and less overlapped. It had two singing areas, the one was the central singing area near or around the nesting site and the other was used as the area for song-duels against the neighboring males. This area was 100 to 200m apart from the nesting site. The nest sites were in short grass areas of Sasa type, but the song-posts were at the top of small bushes. Nests tended to be concentrated but not forming a colony as in E. schoeniclus. At home range boundaries, some chases and actual combats were observed frequently.
6. The home range of E. fucata was selected in short grass areas of mixed Sasa-Miscanthus types, with song posts on the top of small bushes. The nest sites were dispersed at regular distances and never in the form of a colony. The singing area was around the nesting site. The feeding ground was both the short grass areas of Sasa type and bare grounds with scattered short grasses. Any direct relationships between the singing area and feeding ground or between the feeding grounds of female and male were noticed.
7. E. schoeniclus-E. yessoensis type home range related to tall grass area has a possibility to become compressed into a loose colony with wide feeding ground separated from the nesting site.
8. E. fucata-E. cioides type home range related to short grass areas with scattered bushes, has not the possibility to form a colony. Such home ranges are dispersed at regular distances within the habitat.
9. E. aureola and E. fucata selected similar habitat and competition seemed to exist between them, but not with E. schoeniclus. As a consequence, E. aureola and E. fucata tended to avoid the habitat overlap, but no competition was noticed either between E. aureola and E. schoeniclus or between E. fucata and E. schoeniclus.