An investigation into sexual motivation and behavior in female Goeldi's monkey (Callimico goeldii): effect of ovarian state, mate familiarity and mate choice.

Four adult female Callimico were studied in terms of their sexual motivation relative to three unrelated adult males using an operant paradigm followed by a pair test or a two-male choice test. Reductions in urinary cortisol concentrations and the duration of immobility were used as indicators of subjects' adjustment to the experimental situation. When females were tested with unfamiliar males there was no effect of ovarian state on operant or species-typical measures of female sexual motivation. When females were retested with the same males after a 1-week familiarization, sexual motivation was higher during the peri-ovulatory phase than during the post-ovulatory phase in terms of operant but not in terms of species-typical proceptive behavior or in terms of receptive behavior. During the familiarization periods, female sociopositive behavior and sexual motivation demonstrated marked variation depending on the identity of the male. Males with which females demonstrated high sexual motivation during familiarization were the object of equal amounts of female operant behavior during pair tests and two-male choice tests; males with which females had demonstrated low sexual motivation were the objects of less female sexual motivation under conditions of female choice than in pair tests.