Selection of den sites and chronology of denning by black bears in the eastern Sierra Nevada and western Great Basin.

Use of dens during winter is an important strategy for American black bears () for both energy conservation and reproduction; and occupancy of suitable den sites has implications for reproductive fitness. Denning strategies may change as a result of changing climatic conditions and habitat loss. Black bears occupy arid environments in the eastern Sierra Nevada and the western ranges of the Great Basin Ecosystem.