満1歳のニホンザルにおける長期間母子隔離と母子再出会わせ

抄録

Infant Japanese macaques are psychologically as well as nutritionally dependent upon their mothers. Near the age of one year, however, infants become independent of their mothers and increasingly involved in social interactions with other group members. Previous studies have shown that maternal separation during an infant's first year of life can produce social deficits and stereotyped behaviors. The present experiment was performed to determine the effects on infant behavior of prolonged maternal separation at 13 months of age. The subjects were three mother-infant pairs of Japanese macaques. Each of the three mothers was born and lived in the same free-ranging group for a period of time varying between 1 year and 5 years. One of the infants was born and lived in the free-ranging group for nine months. The two remaining infants were lab born. Data were collected during four weeks prior to separation, six months during separation, and four weeks following reunion in the laboratory. Individual differences were observed in certain aspects of infant behavior during each of the experimental stages. The present findings indicate that the behavioral differences between infants were correlated with the length of time the infants and their mothers had lived in the free-ranging group, the interactions between the infant and its mother during the pre-separation stage, and the interactions between the infant and its mother during the reunion stage.