Comparison of infant care in family groups of the common marmoset (Callithrix jacchus) and the cotton-top tamarin (Saguinus oedipus).

The involvement of parents and siblings in infant care in similarly composed groups of common marmosets (Callithrix jacchus) and cotton-top tamarins (Saguinus oedipus) was compared during the infants' first 8 weeks of life. The results indicate an earlier infant independence in C. jacchus than in S. oedipus due primarily to a more frequent rejection of carried infants in C. jacchus. There was no species difference in extent of maternal involvment in carrying infants. However, S. oedipus fathers carried infants significantly more often during weeks 5-8 than did C. jacchus fathers. Siblings were generally more involved in infant care at an earlier infant age in C. jacchus than in S. oedipus.