ABSTRACT
From the standpoint of natural selection, reduction in age of first reproduction potentially will have major advantages, both by increasing the number of offspring and by reducing generation time. Relative to other mammals of comparable size, anthropoid primates might be considered as poor reproducers: in ecological jargon they are characterized as K-selected. That is, monkeys and apes have relatively long gestations and long infant and juvenile stages, small litter size and a long interval between successive births. The transition from the juvenile period to that of adolescence is delineated in many species by the presence of externally visible indicators of reproductive maturation. For females this usually means presence of sex skin swellings or particular other skin swellings or coloration, externally visible menstruation, or onset of estrous behavior. The main comparative studies of Japanese macaques are a result of different amounts of food provisioning, or absence of provisioning, in otherwise either wild or at least free-ranging animals.
