Infantile Calls of Silvery Marmosets (Callithrix argentata melanura) during the first 10 weeks

Abstract

Marmosets have a monogamous reproductive strategy that involves al members of the family; the ontogeny of communication and interaction of youngsters with members of the group is thus very important. The vocalizations and behaviour of five Callithrix argentata melanura infants during the first then weeks after birth were recorded, and the Calls they emitted analyzed spectrogaphically. Five Calls form the main part of their vocal repertoire: the infantile Call GECKER and NGA, PHEE, TSAK and TRILL. All Elements composing these are irregular and imperfect versions of some of the adult ones. Around the age of 4-6 weeks, when infants are acquiring their independance, GECKER nearly disappears and the other Calls are ultered at a progessively higher frequency. The peak of Call Rate coincides with the first two weeks that infants are spending most of their time off adults’ back. Vocal communication is closely interrelated with social behaviour during early stages of ontogeny, since the need arises to use specific Calls for each si uktion.