Meeting Abstract
When, how often, and with whom to mate are fundamental questions that directly impact the mating system of a population and that have tremendous implications for the evolutionary process in general. Although these questions have been fairly well studied in males, comparatively few studies have focused on investigating female mating tactics or reproductive decision-making. Here we asked how differential access to mates influences the occurrence of mixed paternity and overall reproductive success in socially monogamous female prairie voles ( Microtus ochrogaster ). We created male- and female-biased sex ratios of prairie voles living in semi-natural outdoor enclosures for approximately four weeks. After trapping, we ran paternity analyses to determine the identity and number of mating partners females had and the number of offspring each female produced. Counter to our original expectation, we found that when males outnumbered females, females had fewer mating partners and mixed paternity was rare. However, when females outnumbered males, females had multiple partners and high rates of mixed paternity. Although we did not determine which animals had formed pairbonds, these data are consistent with other studies that suggest that males preferentially impose pairbonding on females through mate guarding. This idea is reinforced by the result that females’ reproductive success (number of offspring) increased as a function the number of male mating partners they had, regardless of the sex ratio context.
