OBSERVATIONS ON THE INTERACTION BETWEEN ADULT GROUP MEMBERS, GROUP MEMBERS WITHOUT REARING EXPERIENCE AND INFANTS IN THE COMMON MARMOSET, CALLITHRIX-JACCHUS

This study describes the reactions of adult, rearing-experienced members of three Callithrix jacchus families to interactions between animals without rearing experience and infants. The direct involvement of adult group members in situations in which inexperienced animals interact with infants decreases as the infants become older. Inexperienced animals will approach infants more seldom, if adult, rearing-experienced animals are nearby. Adult, rearing-experienced members of the group display primarily noninteractive behavior. This is especially true when no physical contact has taken place between an inexperienced animal and the infant, or if contact was initiated by the infant. Most of the dissociative reactons were observed in the context of competition for objects and play activity. However, there was a similarly high percentage of associative behavior towards inexperienced animals during play activity. In the episodes observed, the adult, rearing-experienced animals displayed mainly taking care behavior towards the infant but never any dissociative behavior. The following points appear to be of significance for the way adult, rearing-experienced members of the group behave: spatial distance between inexperienced animal and infant; which party was the initiator of the interaction; the level of experience already acquired by the animals without previous rearing experience, and the level of maturation of the infant.