关键词: 根田鼠, 配偶选择, 熟悉性, 婚配制度

Abstract: Many behavioral experiments compared monogamous species with polygamous one in microtine rodents show that the mating systems are associated with mate choice among individuals，and a major component determining nature of the sexual selection is familiarity between males and females. The long- and short-term effects of familiarity on both sexes’ mate choices of root voles (Microcus oeconomus) was examined by three kinds of laboratory experiments. They were mate preference of the experimental root voles for the familiar versus the unfamiliar，the partner versus the unfamiliar and the partner versus the familiar stimulus ones. Familiarity was established by housing amale with an unrelated female in a plastic breedingcage for 8 h each day until they were found todisplay sexual behaviors. Partnership referred as the relationship between a pair of male and female having bred at least one litter of offspring. During 30 min trial, two stimulus voles were tethered in two choice chambers of a Y-shaped maze respectively，while the experimental vole was allowed to enter either of the two choice chambers from the central arena. The experimental vole was scored for duration and frequency of visit，social-investigation, copulatory behavior, aggression and amiability with each stimulus vole. Behavioral comparison between the two stimulus voles was achieved by a Wilcoxon matched-pairs test. The results showed that the females preferred the familiar rather than unfamiliar males, the partner rather than unfamiliar males, the partner rather than familiar males in the social behaviors except for copulatory behavior with no significant level. However, the males made no a preference for the familiar versus the novel females，nor the partner versus the novel females. These data suggested that female preference for familiar males and males having nomate choice between familiar and strange females may be proximate behavioral processes underlying traits in mating system of root voles. Thus, female mating monogamously and male non-monogamously can be explained by the hypothesis that the mating system could be polygynous in root voles.

Key words: Root vole(Microtus oeconomus), Mate choice, Familiarity, Mating system