SEASONAL HABITAT SELECTION BY ELK IN NORTH CENTRAL UTAH

Understanding anthropogenic and environmental factors that influence seasonal habitat selection is critical in establishing conservation objectives for wildlife populations. However, many resource selection studies provide inferences only for single seasons, potentially masking factors essential to populations during other times of the year. Our objective was to model elk (Germs elaphus) habitat selection for 4 seasons to identify factors influencing selection within and across seasons. Using aerial relocation data, we evaluated seasonal habitat selection for 46 radio-marked, migratory adult female elk in a 6123-km(2) landscape in north central Utah, USA, from 1993 to 1997. We evaluated habitat use and availability within estimated seasonal range boundaries by using binary logistic regression to model habitat selection. Habitat use was measured as a response to predictor variables collected from analysis regions around elk locations. Habitat use was compared to habitat availability by measuring those same variables collected from randomly located analysis regions. Our results showed that roads, topography, and vegetation cover influenced elk habitat selection within and across seasons. Roads did not influence elk habitat selection in spring; rather, elk selected areas with aspen (Populus tremuloides) at higher elevations. In summer, elk selected forage-rich habitats, particularly aspen and mountain brush at higher elevations and on cooler aspects. In fall, elk selected sites with steeper slopes at higher elevations in areas with greater cover of aspen and mountain brush than was available in seasonal range boundaries. In winter, elk selected sagebrush (Artemisia spp.)-meadow cover on steeper slopes at lower elevations away from major roads. The full array of seasonal habitat selection patterns we found provides managers with greater options for setting conservation objectives for elk on a year-round basis.