Plants and Animals:
Mammals

Early settlers described both deer and coyotes (Canis latrans), which they referred to as prairie “wolves” or “gray wolves” (Hoffmeister, 1989). Pioneers and explorers also noted beaver (Castor canadensis), raccoon (Procyon lotor), and foxes, which they trapped for furs. The red fox (Vulpes vulpes) inhabits the grasslands and open shrublands, whereas the gray fox (Urocyon cereoargenteus) prefers forest habitat, including the wooded margins of streams. All of theses mammals occur at Midewin, along with mink (Mustela vison), which live along streams and rivers. The long-tailed weasel (Mustela frenata), which is on the Illinois watch list (may become threatened), is also present at Midewin. It occurs in a number of habitats in the State, from brushy grasslands to woodlands and disturbed farmlands (Hoffmeister, 1989).

Big Brown Bat John L. Tveten

The red bat (Lasiurus borealis) and the big brown bat (Eptesicus fuscus) are present at Midewin. Red bats roost in trees, shrubs, brush and weeds. The big brown bat prefers vacant buildings.

Whereas the settlement of the prairie and its conversion to agricultural lands severely depleted prairie bird populations, mammals have not suffered to as great a degree. None of the prairie mammals, according to Hoffmeister (1989), have been eradicated as a result of the conversion of the prairie to farmlands. Some species, in fact, have either become more abundant or extended their ranges because of the greater diversity of habitats.

The mammals present at Midewin thrive in the diversity of habitats that exist at the site. Some of these are true prairie species. The thirteen-lined ground squirrel (Spermophilus tridecemlineatus) is restricted to the Grand Prairie division and the northern part of the state. It prefers prairies with shorter grasses or disturbed, weedy areas. Its distribution coincides with the extent of prairie to the west, and it has become more abundant in the state (Hoffmeister, 1989). The plains pocket gopher (Geomys bursarius) is a prairie species found in medium and fine-textured soils along the Illinois River and east and south of the Kankakee River (Hoffmeister, 1989). It is on the Illinois watch list and occurs at Midewin. The meadow vole (Microtus pennsylvanicus) and western harvest mouse (Reithrodontomys megalotis) also occur at Midewin.

Prairie mammals affect prairie habitat in a variety of ways. The plains pocket gopher reduces the nitrogen content of the surface soil depositing the less nitrogen-rich subsoils at the surface while burrowing. They simultaneously increase the nitrogen content of the lower levels of the soil by creating dens at greater depth where they store food and deposit waste (Zimmel, et al., 1990).

Thirteen-lined Ground Squirrel John L. Tveten