A population study of the japanese wood mouse,Apodemus speciosus (Mammalia: Muridae), with reference to its social behavior

The role of social behavior on the population regulation of the Japanese wood mouse, Apodemus speciosus, was studied in the Ashu Experimental Forest of Kyoto University by monthly trapping and direct observation on the social behavior at the artificial feeding site. The census was carried out from May to October in 1974 and 1975, and the direct observation in June, August and October, 1975. In the study area, the Japanese wood mouse has two breeding seasons in a year: in spring and in autumn. Minimum survival rate was high in the non-breeding season and low in the breeding season. It was negatively correlated to the number of sexually active adults in both sexes. Home ranges of females tended to be mutually exclusive, and female residents prevented the settlement of female immigrants. On the other hand, home ranges of males overlapped largely and males had a straight social hierarchy. Subordinate males tended to disappear more often than dominant males did, but male residents did not hinder the settlement of male immigrants. Males may regulate their number by driving out the subordinate males, while females by spacing behavior.