Scent counter-marking by male meadow voles: Females prefer the top-scent male
Scent counter-marking, in which one individual deposits scent in close proximity to the scent of another individual, is a widespread but poorly understood aspect of olfactory communication. Recent work with golden hamsters suggests that animals may have specially evolve mechanisms for determining which individual has marked most recently, and this work emphasizes the need for studies with other species. In Experiment 1 it was shown for the first time that male meadow voles, Microtus pennsylvanicus, scent mark with urine and anogenital scents and probably also counter-mark with these scents. Female meadow voles, after investigation of an are marked by two males, preferred the whole-body odours of the male that had marked the arena most recently (Experiment 2). After females investigated a male's home cage that had just been marked by another male, they again preferred the whole-body odours of the male that had marked in the cage most recently (Experiment 3). These results demonstrate that female voles, like male hamsters, can distinguish the top or most recent individual's scent from the bottom or older scent in places marked by two male, and further indicate that female voles may prefer the individual that deposited the top scent. Taken together, the results suggest that counter-marking by male voles may be a type of comparative advertising and that females may base mate-choice decisions on information from the pattern of such counter-marks.
Johnston, R., Sorokin, E., & Ferkin, M. (1997). Scent counter-marking by male meadow voles: Females prefer the top-scent male. Ethology, 103 (6), 443-453. https://doi.org/10.1111/j.1439-0310.1997.tb00159.x