LAUSR

Abstract Core activity areas are the most important sites within an animal’s home range as they contain the greatest density of critical resources. Because these areas are small and intensively used, they can affect the total distances covered by animals searching for resources. Our objective was to document which habitat variables affect core area selection by female mule deer (Odocoileus hemionus) in an arid environment, and to learn which variables affect their displacement within these areas. Using radiotelemetry, from 2012 to 2014 we monitored seven female mule deer. We estimated their core areas, and with this information we identified and classified the location records as inside or outside of the core area. For each record, we also recorded variables related to time (month, time of day), environmental conditions (temperature, relative humidity), and habitat characteristics (plant association, distance to the nearest water body, slope), and used them to predict the presence of the deer in the core area using Classification and Regression Trees (CART). The same variables were analyzed using a GLM to determine which factors explain variations in displacement distance. The most important variable in core area selection was the distance to the nearest body of water (