Demography of the Formosan Wood Mouse, Apodemus semotus
Journal of the Faculty of Agriculture Kyushu University
The demography of two Apodemus semotus populations in a Cg$tomeria plantation and a small isolated renewed stand of Chamaecxbaris was studied from 1985 to 1989 in the Alisan area, Taiwan. The annual fluctuation in density was characterized by a highest peak in August (66.7/ha in the Cqbtomen'a habitat and 51.4/ha in the Chamaec@aris habitat), a slight peak in winter and declines in both autumn and spring. The high densities probably resulted largely from habitats having monospecific occupancy.
... pecific occupancy. Monthly survival rates and recruitment rates showed almost no significant correlation with the density values. There were some seasonal tendencies with a higher proportion of females in summer. Diet analysis in August revealed that fungi constituted the main part of the diet. Males with fully descended testes had two considerable peaks in April and August, and females were reproductively most active in late spring and autumn when the many were lactating. The highest peak at the onset of breeding in August was caused by the high percentage of new individuals including many male transients entering into the population. The spring decline in A. semotus was qualitatively similar to that in A. sylvaticus, and spacing behavior of adults might account for the modification in demographic parameters associated with the beginning of two peaks in the annual breeding cycle.