From dependence to sexual maturity: the behavioural ontogeny of Callitrichidae

Abstract

This chapter reviews data on behavioural ontogeny in the four callitrichid genera, and presents more detailed data on five Callithrix jacchus infants. Callitrichids are unique in the intensity of their relations to infants. The newborn, usually twins, may be carried from the first day by group members other than the mother. Weaning occurs from 9-13 weeks, when most of the food ingested is obtained through sharing or stealing. Agonistic behaviours may appear, as well as scent-marking. At the juvenile stage (beginning at 4-7 months) ‘twin fights’ may occur; particularly between same-sexed twins, determining status differences. At the sub-adult stage (beginning at 9-14 months) the young animal has the size and appearance of an adult, has mastered most of the adult behavioural repertoire, and achieves puberty. Although puberty takes place at this time the young does not conceive. At the adult stage (beginning at 12-21 months) sexual maturity is attained. Approximately every five months a new set of twins is born. Interactions with infants depend on the animal’s age and previous experience. The behavioural ontogeny shows many similarities among the callitrichid genera, although some important differences call for further investigation.