Sources of scent used by prairie voles, Microtus ochrogaster, to convey sexual identity to conspecifics

The presence or absence of specific odor-producing tissues has been used to suggest phylogenetic relationships among microtine rodents, but has not been related to patterns of social organization. We examined the sources of sex-specific scents in prairie voles, Microtus ochrogaster, using a preference task. Prairie voles have eight sources of sex-specific scents. Four scents, namely those from the urine, feces, anogenital area, and mouth were more attractive to opposite- than same-sex conspecifics. Three scents were attractive to one sex but not the other. Scent from the back of females was attractive to males and scents from the chest and head–neck–ears of males were attractive to females. Scent from the male posterolateral region was attractive to both females and males. We then compared these eight sources of scent with the known sources of scent from meadow voles, Microtus pennsylvanicus, a species whose social system is unlike that of prairie voles. Prairie voles have more sources of sex-specific scent than meadow voles. This difference supports the hypothesis that the number of sources of sex-specific scent is greater in a social species (prairie voles) than in an asocial species (meadow voles).