THE FACILITATIVE INFLUENCE OF EXPERIENTIAL FACTORS ON THE PARENTAL BEHAVIOR OF MALE-MICE (MUS MUSCULUS) .1. THE EFFECTS OF THE EXPERIENCE OF COPULATION AND COHABITATION WITH A PREGNANT FEMALE

Effects of the experience of copulation and cohabitation with a pregna nt female on male parental behavior were examined in ICR-strain male m ice. The experience of copulation and/or cohabitation with a pregnant female promoted parental behavior, although the cohabitation with a pr egnant female per se failed to inhibit infanticide in male mice. There fore, it is possible that the facilitation of parental behavior is cau sed by a motivation independent from that of the inhibition of infanti cide in male mice. As to the facilitation of parental behavior, the ef fect of copulation was stronger than that of cohabitation with a pregn ant female, and these 2 effects seem to be additive. It is possible th at there are 2 independent mechanisms for the facilitation of parental behavior in male mice.