%0 Journal Article
%T Resource selection of mule deer in a shrub坼steppe ecosystem: influence of woodland distribution and animal behavior
%A Alisa Ellsworth
%A Kelley M. Stewart
%A Sabrina Morano
%A Thomas Dilts
%A Vernon C. Bleich
%J Ecosphere - Wiley Online Library
%D 2019
%R https://doi.org/10.1002/ecs2.2811
%X Ungulates inhabiting arid ecosystems are reliant on productive forb and shrub communities during summer months to meet nutritional demands for survival and reproduction. In the western United States, expansion of woodland vegetation into shrub坼dominated communities and the potential loss of habitat are of concern with regard to animal populations reliant on robust sagebrush shrub and forb vegetation. We used mixed坼effects logistic regression to model resource selection of female mule deer (Odocoileus hemionus) during the summers of 2005每2008. We considered selection at two spatial scales, and during three daily activity periods (night, crepuscular, and mid坼day) corresponding to resting and foraging. We evaluated habitat variables related to vegetation type, site productivity, terrain attributes, and fine坼scale abundance of pinyon每juniper cover. Those attributes allowed us to account for variation in site productivity and animal behaviors that could obscure the true relationship between density of pinyon每juniper woodland and habitat use by mule deer. We detected observable differences in habitat use by mule deer among the three activity periods with significant differences in movement rates. Deer were most active during crepuscular periods corresponding with foraging activity, and least active mid坼day when temperatures were highest. Summer habitat consisted of sites with high potential productivity, greater shrub abundance, and greater proximity to riparian areas. Deer avoided high levels of tree cover (>40% coverage) at all spatial and temporal scales, and in general selection declined with increasing pinyon每juniper cover, particularly during foraging periods. Nonetheless, mule deer selected areas with low to intermediate tree cover (10% to 40%) during resting periods and avoided areas of productive shrub and forb vegetation and riparian areas, when surrounded by denser stands of pinyon每juniper cover. These results emphasize the importance of productive shrub and forb vegetation to mule deer inhabiting semi坼arid regions and suggest that low levels of tree cover are beneficial, especially during resting periods. Nevertheless, dense pinyon每juniper cover was generally avoided even in areas of high site productivity. These relationships lend support to the concern that increases in large, dense stands of pinyon每juniper reduce availability of summer habitat and alter patterns of resource selection for mule deer, a shrub坼dependent ungulate. Vegetation changes have the potential to influence animal populations through shifts in dominant plant communities, loss
%U https://esajournals.onlinelibrary.wiley.com/doi/full/10.1002/ecs2.2811