Resource selection and movements by female mule deer Odocoileus hemionus: effects of reproductive stage

Recent declines of mule deer Odocoileus hemionus, ostensibly a result of low rates of recruitment, highlight the importance of understanding relationships between parturient females and their critical habitats. We estimated timing of parturition for 20 Mule deer ill northeastern Oregon, USA, using movement data from global positioning system (GPS) collars in 2005 and 2006. We then evaluated patterns of resource selection by female mule deer during late gestation, the week of parturition, and subsequent lactation to determine how different stages of reproduction influenced habitat selection. Movement rates of all but one deer declined sharply between late-May and mid-June, when female mule deer give birth in northeastern Oregon. Patterns of resource selection also varied Substantially relative to the estimated time of parturition. Prior to parturition, female Mule deer selected gentle south-facing slopes dominated by ponderosa pine Pinus ponderosa and avoided permanent water sources. Parturient females also selected areas used concurrently by elk Cervus elaphus. Following parturition, however, females selected steep north-facing slopes dominated by fir Abies spp., avoided elk and selected habitat located close to permanent water sources. Stage of reproduction clearly influenced choice of habitat by female mule deer. Mule deer management plans should consider potential seasonal variability in the relative importance of forage, risk of predation and competition.