Reproductive status of adult daughters in family groups of common marmosets (Callithrix jacchus jacchus).

Urine samples were collected from 6 pubertal female common marmosets at approximately 3-day intervals over a period of 3-7 months. All 6 females were the eldest daughters in their family groups. 3 of these females were subsequently removed from their families and sampled in isolation for another 2-3 months. Levels of urinary pregnanediol-3 alpha-glucuronide were measured by radioimmunoassay in order to establish whether these females showed ovarian cyclicity. No cyclical fluctuations in the levels of pregnanediol were observed in the females housed with their families even though the females were of a reproductively mature age. Cyclicity was quickly established (within 18-22 days) when the females were removed from the family. These results are discussed in the light of similar recent investigations on callitrichid reproduction and the behavioural implications are considered.