Population dynamics of Japanese monkeys with special reference to the effect of artificial feeding

Population dynamics of Japanese monkeys (Macaca fuscata) have been studied at Mt. Ryozen, central Japan, between 1969 and 1980. The troop had been artificially fed until August 1973 and, since then, has been living in its natural habitat without artificial feeding. Increase in body weight, primiparous age, age-specific natality, survivorship and mortality, population and biomass growth rate, and age of disappearance of young males were compared between the two study periods, with and without artificial feeding. Comparison of population parameters in each study period was also done between social classes, central and peripheral. As shown, in table VII, it was revealed that artificial feeding was an important factor in population growth and, furthermore, that this effect was mainly on the kin-groups of the central class of the troop. In the natural habitat without artificial feeding most of the population parameters showed almost the same figure for kin-groups of central and peripheral classes.