POPULATION REGULATION IN THE WOOD MOUSE APODEMUS-SYLVATICUS (L)

Watts (1969) described the population cycle of the Wood Mouse Apodemus sylvaticus as a decline in numbers in spring, a stable period in summ er and an increase phase in autumn. Aggression by adult males was cons idered an important aspect of population regulation limiting male surv ival in spring and juvenile recruitment in summer. However, recent stu dies of range behaviour and experimental investigations suggest that m ale A. sylvaticus are not relevant in population regulation and that t he principal regulating factors act on female reproductive success. Fe male reproductive activity is determined by spatial interactions which , in turn, are determined primarily by the density of females and the proportion of female immigrants in the population. The only impact adu lt males may have on population size is through infanticide and compet ition with the females for food.