Observations on the Interaction between Adult Infant-Carrying Animals and Group Members without Rearing Experience in the Common Marmoset, Callithrix jacchus

Abstract

The behavior of animals without rearing experience towards adult, infant-carrying animals and towards the infants being carried, and the reactions of the adult, infant-carrying animals in the latter case are described here on the basis of the observations made of three family groups of Callithrix jacchus (marmosets). In about 50% of the episodes observed, the animals without rearing experience do not establish physical contact with either the infant carrier or the infant; up to 10% of the time they interact with other group members who are also in the vicinity of the infant-carrying animal, physical contact with either the infant carrier (a parent infant carrier is preferred) or the infant accounts for half of the remaining episodes, respectively. More than half of the time when an animal without rearing experience seeks contact with them, the infant carriers do not display any interactive behavior. The percentage of dissociative behavior is highest when the animals without rearing experience seek physical contact with the infants. The percentage of associative behavior is highest when these animals seek physical contact with the infant carrier. Infant carriers break off contact more frequently than do the inexperienced animals. The reaction spectra of the parents differ from those of the adult sons and daughters. The results point to a relatively high level of tolerance on the whole, on the part of the infant-carrying animals; they only react agonistically in situations that are potentially hazardous for the infant. Previous observations have to be qualified by means of the quantified data.