Ecological replacement of the Deer Mouse, Peromyscus maniculatus, by the White-footed Mouse, P. leucopus, in the Great Lakes region

Long, Charles A. 1996.Ecological replacement of the Deer Mouse, Peromyscus maniculatus, by the White-footed Mouse, P. leucopus, in the Great Lakes Region.Canadian Field-Naturalist 110(2): 271-277.The possible ecological replacement of the boreal, long-tailed Forest Deer Mouse Peromyscus maniculatus gracilis, by the White-footed Mouse, P. leucopus noveboracensis, in Wisconsin was studied by analysis of the zoogeography (parapatric distribution and relict populations of P. m. gracilis in the south and on islands), and by surveying relative population abundance on Washington Island, where competition probably commenced in 1987, upon the arrival of P. leucopus.In Wisconsin, the geographic range of P. leucopus is expanding northward, and P. maniculatus gracilis has vanished in the south and on the Door Peninsula.The White-footed Mouse thrives in brushy and dry forest habitats (often nesting in ground burrows), and the Forest Deer Mouse seems both adapted to high tree branches and cavities, to cold weather, and to boreal (conifer, mixed conifer) forests.On Washington Island, after an initial increase of P. Jeucopus and the concomitant near extinction of P. m. gracilis, both species have coexisted at low to medium densities during the mild winters of the past three years.