The amount of time (mean ± sem) that male and female meadow voles spent investigating the scent mark of the opposite-sex, top-scent donor of a mixed-sex over-mark with which they had four days of olfactory experience and that of a novel, opposite-sex conspecific as well as the time they spent investigating the scent mark of the opposite-sex, bottom-scent donor of a mixed-sex over-mark and that of a novel, opposite-sex conspecific. * indicates a statistical difference in investigation time between scent mark pairings (p < 0.05; multiple paired comparisons, Holm-Sidák Method).