Reproduction Rate Strategies in White-Footed Mice

A photoperiod is the measure of the length of daylight each day. This value can potentially determine the behavior and/or biological processes of many species of animals and plants. Peromyscus leucopus (white-footed mouse) responds to changes in photoperiods by altering its reproductive strategies. White-footed mice adjust their reproduction rates because of the high cost of reproduction in the winter and in short photoperiods. In our research we have looked at two groups of mice: responsive mice which reproduce March through November and non-responsive mice which reproduce all year around. Interestingly, in Williamsburg, VA there exists a mixture of the responsive and non-responsive mice. The coexistence of these two types of mice suggests some kind of genetic variation. We have created nonlinear discrete population models to better understand the population dynamics of the two phenotypes of mice and whether coexistence over time is possible using our assumptions on environmental conditions and mice characteristics. Using one of our models, it seems that the coexistence of these mice is sensitive to the genetic inheritance of photoresponsiveness