Occurrence and Distribution of Mammals on the McChord Air Force Base, Washington

In the fall of 2005 and spring and summer of 2006, The Nature Conservancy, in cooperation with the Washington Department of Fish and Wildlife and Cascadia Research Collective, conducted a mammal inventory on McChord Air Force Base (MAFB). The military has a vested interest in maintaining habitat and species by congressional mandate and the corresponding burden of recovery. Six major habitat types were designated for trap-line transects; additional directed efforts were employed to target specific species. The resulting effort documented the presence of 36 species, eight of which were bats. Documented species of note include the western gray squirrel (Sciurus griseus), a state “threatened” species, detected by hair-snag tubes; long-eared myotis (Myotis evotis); long-legged myotis (Myotis volans); and the Yuma myotis (Myotis yumanensis). Mammalian diversity on MAFB was influenced by three factors: water (either open water or wetland habitat); large, contiguous tracts of undeveloped acreage; and continuity with Fort Lewis, a large military base immediately adjacent to MAFB. Additionally, Scotch broom (Cytisus scoparius), an invasive woody shrub, was found to support limited mammalian diversity, with the fewest species documented in this habitat type. Given the impending changes due to development, ownership, and climate, this survey will be useful to managers as a baseline for focused species efforts and future comparisons.Environmental Practice 10:116–124 (2008)