1966 年 4 巻 5 号 p. 269-279
1. Based on the request made by the Imperial Household to Yamashina Institute, monthly bird censuses were conducted by seven researchers in the Imperial and Akasaka Palaces in Tokyo during April, 1965 and March, 1966.
2. Census by line transect was made usually by two observers about 50m apart, once or twice per month: 15 times in the Imperial Palace (except August and September) and 11 times in the Akasaka Palace (except January to March).
3. In total 56 species (including wintering ducks and colonial herons) were recorded in the Imperial Palace and 46 species in the Akasaka Palace.
4. The number of species and individuals per census day varied 15-24 and 319-923 (2 hours course) in the Imperial and 9-24 and 150-306 (1 hour course) in the Akasaka Palaces respectively.
5. The result of each census day is shown by species in three tables (two for the Imperial and one for Akasaka Palace).
6. A comparative table is given showing the relative abundance of main species in the two palaces with indexes of: occurrence rate, mean number of occurrence, its dominance value in avifauna, recorded season and breeding evidence.
7. Specific accounts are only given briefly for main species. More migrants were recorded in spring and autumn in the Akasaka Palace, probably due to its elevated position.