Local distribution of two swallows of genusHirundo, and breeding success ofH. rustica

Summary The distribution of nests of the swallows was investigated in 1957, 1962 and 1963 at Koriyama, Nara Prefecture. Roughly speaking, the nest ofHirundo rustica was located in the urban areas, and that ofH. daurica in the rural areas. This subdivision of the habitat seems to be due to the traditional system more or less depending on some interactions between them. The trend of the decrease in the nest number has not been found out from the 3-year studies. The observation on the breeding success ofH. rustica was done in 1963, and it was estimated that 869 youngs in total fledged out from the study area.