Resumption of sexual activity affects mother-infant interactions in Japanese macaques

This study evaluated the responses of infant Japanese macaques (Macaca fuscata) to their mother's resumption of mating. Mothers and infants were observed before, during and after the mating season. Observations carried out during the mating season were subdivided according to the mother's consort activity with mature males. During consorts, significant decrements in mother-infant ventroventral contact and proximity, and in the roles played by mothers in maintaining contact and proximity were observed, while maternal rejection increased significantly. Social behaviour of infants and allomaternal care they received were unaffected by the mother's consort activity. Effects of consorts were more evident in female than in male infants, but were not influenced by the infant age or by the quality of the relationship it had with its mother before the mating season. These results do not support the hypothesis that the effects of the mother's resumption of mating may parallel those of experimental mother-infant separation.