Social influences on sexual maturation of female Saguinus oedipus oedipus

The hypothesis tested was that Saguinus oedipus oedipus females housed with adult males would mature, sexually, at an earlier age than females remaining in their natal family groups. Six females were housed with strange, unrelated males. Five females remained in their natal groups. Blood samples were taken twice weekly, and the plasma was assayed for progesterone. Sexual maturation was operationally defined as that age at which plasma progesterone levels became consistently detectable. Females housing with males did mature at an earlier age than females remaining in their natal groups. In addition, it was noted that the presence or absence of a healthy, reproductive mother in the natal group was not related to the daughter's maturation age. However, whether the natal group, as a whole, inhibited maturation of young females, or an unrelated male accelerated maturation, or both, remains unknown.