Multiple paternity in meadow voles (Microtus pennsylvanicus): investigating the role of the female

Multiple paternity in single litters conceived in the wild was recently dem onstrated in meadow voles (Microtus pennsylvanicus). In this study, we used an experimental approach (males tethered and females allowed to mate freel y with one or several males) to investigate the role of female meadow voles in multiple paternity. We found that among 29 (of 39) females that copulat ed during our experiment, 79.3% chose to mate with more than one male. Fema le behavior in meadow voles thus clearly promotes multiple paternity and th eir role is an active one. Some of the hypotheses explaining promiscuity in meadow voles should be reconsidered in light of this result. We do not kno w the primary determinant of female mate choice, but male body mass played a secondary role in driving female preferences. The partial dependence betw een male body mass and female choice, coupled with the active role played b y females, indicates that intersexual selection has the potential for reinf orcing the effects of intrasexual selection (male-male dominance relationsh ips) in this species. Finally, we demonstrate that the time period over whi ch tests are conducted is an important part of the design of experiments ai med at understanding the role of females in multiple paternity.