I suspect that climate isn’t the only factor that influences where bears choose to den. Habitat may be just as critical. In a study from Yellowstone (Judd et al. (1986) Denning of grizzly bears in the Yellowstone National Park area. ), the authors found that “Dens occurred on all aspects, although northerly exposures were most common.” A study in Scandinavia (Manchi and Swenson. (2005) Denning behaviour of Scandinavian brown bears Ursus Arctos.) found that the most common den type used by Scandinavian brown bears was dug under anthills. The authors state, “This preference may be due to the combined effects of high insulation efficiency and high availability.” Since north facing slopes in Yellowstone are cooler and wetter, those slopes can also harbor a different assemblage of plants. Perhaps, certain plants and soils are preferred by denning bears.