Response of Prairie Voles, Microtus ochrogaster (Rodentia, Arvicolidae), to Scent Over‐marks of Two Same‐sex Conspecifics: A Test of the Scent‐masking Hypothesis

Abstract

Previous work shows that after investigating a same‐sex over‐mark, two nonmonogamous species, meadow voles and golden hamsters, preferred the odor of the top‐scent donor to that of the bottom‐scent donor, and behaved as the odor of the bottom‐scent donor was not familiar. This finding supported the scent‐masking hypothesis; one of three hypotheses suggested previously to account for how an animal responds to the overlapping scent marks of two same‐sex conspecifics. The present experiments tested whether one of these hypotheses, either scent‐masking, scent‐bulletin‐board, or scent‐blending, predicts how a monogamous species, the prairie vole, responds to such over‐marks. Our data show that none of the three hypotheses adequately describes the way in which prairie voles respond to conspecific over‐marks. Although prairie voles preferred the top scent to the bottom scent, they behaved as if the latter scent was familiar and less important than a novel scent (a scent not part of the over‐mark). Overall, the data suggest that the manner in which males and females respond to same‐sex over‐marks reflects the different tactics they may use to attract and compete with conspecifics in monogamous and nonmonogamous species.