Early olfactory experience, novelty, and choice of sexual partner by male rats

After rearing by citral-scented or unscented dams, adult male rats were given simultaneous choices of citral-scented or unscented female partners in approach, contact, and sexual behavior tests. There was no evidence that mate choice had been affected by the early rearing experience. In Experiment 1, both citral and control males approached citral-scented females in a T-apparatus at slightly above chance levels and exhibited no differences in copulatory behavior during successive pairings. In Experiment 2, normally reared males directed their first mount more rapidly to a citral female, but otherwise mated equally with the scented and unscented females. In Experiment 3, citral-reared males approached citral and unscented females equally, whereas controls approached citral females less often. With 2 females in the same arena (Exp. 3), the first mount was more rapid when the odor of the partner matched that of the dam, but no other measure of sexual behavior was affected by the partner's odor. Despite the importance of early olfactory experience for the development of social behavior, a preference for estrous-related odors is evidently not learned before mating experience. Under some circumstances, a novel odor added to familiar conspecific odors may attract naive males to potential partners.