Abstract:

Callithrix jacchus is a diurnal non-human primate with elaborate vocal repertoires, sophisticated acoustic communication, and highly social behaviours. Boasting high fecundity and a short developmental cycle, this species regularly bears litters of genetically similar siblings, rendering it a powerful laboratory model to disentangle how intrinsic and extrinsic factors shape vocal development. Newborn Callithrix jacchus are capable of producing the majority of species-typical adult vocalizations on postnatal day 1, and profound remodelling of infant vocal repertoires takes place over the first two postnatal months. Juveniles with frequent vocal interactions with their parents exhibit faster vocal development, while socially isolated individuals show delayed vocal maturation. Therefore, genetic factors lay the foundational template for vocal production in Callithrix jacchus, with postnatal social interactions serving to further calibrate and refine these vocal signals. Additionally, ecological factors strongly shape mother–infant vocal communication in this species. Habitat characteristics govern sound propagation; predation risk fuels the evolutionary specialization of alarm vocalizations; social structure and cooperative breeding create intricate social contexts for acoustic exchange; and resource availability directly regulates the intensity of vocal signals. As one of the most widely used non-human primate laboratory animals, Callithrix jacchus displays remarkably human-like traits in socially guided vocal learning, which renders it an invaluable experimental model for dissecting the convergent and divergent mechanisms governing vocal development and communication across non-human primates and humans, while also advancing investigations into language evolution and clinical voice disorders. This paper focuses on vocal development and ecological adaptive evolution of Callithrix jacchus, and underscores its distinctive advantages as a laboratory model for biomedical research. It is expected to offer a theoretical framework and an experimental reference for evolutionary investigations of acoustic communication in non-human primates, as well as translational research on human speech disorders.

Key words: Callithrix jacchus, Vocal development, Acoustic communication, Socialization, Non-human primates