Effects of Climate Change on the Distribution of White-footed mouse (Peromyscus leucopus), an Ecologically and Epidemiologically Important Species

Abstract

Peromyscus leucopus (White-footed mouse) is a common species found throughout the eastern United States and a key component of midwestern ecosystems. Recently, the species has been expanding its range from the Lower Peninsula of Michigan, to the Upper Peninsula, possibly due to increasing temperatures. Given the shifting environmental conditions, understanding current environmental determinants of current P. leucopus distribution can help predict how the species will respond to global climate change. Such insight in turn, is both important for understanding how N. American species communities are likely to be influenced by ongoing climate change and also for applied local conservation efforts. Data on the presence/absence of P. leucopus and environmental variables including elevation, land cover, and climate, such as temperature, and precipitation, were used to predict habitat suitability and current distribution in Michigan. We assessed the fit of a model that uses maximum entropy approach (MaxEnt) to relate presence to environmental variables by using a cross-validation process and the receiver operating characteristic. Response curves were used to illustrate the relationship between each of the environmental variables and the probability of presence of P. leucopus. And a jackknife test was used to identify those environmental layers that were most important in predicting White-footed mice distribution. Future temperature and precipitation layers were used to predict the possible future distribution of White-footed mice in Michigan and northward. Our analyses indicated that the final model provided a reasonably good fit to the current distribution of the species. Average minimum temperature of April was the environmental layer that contributed most to predicting the current distribution of White-footed mice, whereas, February precipitation reduced the gain of the model most when omitted from the analysis. April average minimum temperature and April precipitation were both positively related to the probability of presence of P. leucopus. The importance of temperature and precipitation suggests that the distribution of this ecologically important species is going to change under future climatic regimes. Indeed fitting the present model to future conditions indicates that the species will expand dramatically northward in the next 50-70 years with many Canadian areas north of Michigan becoming suitable habitat for P. leucopus by 2050.