Document: GIN-3-52-53

Species interactions of Microtus pennsylvanicus, M. ochrogaster, and Peromyscus leucopus at a prairie restoration

TURNER-ERFORT, G.*

University of Illinois at Chicago, Chicago, IL 60607-7060 ¹

Abstract:
With the change in plant community composition of a prairie restoration experiment in northeastern Illinois, there has also been a change in the species compositon of small rodents. At planting, the experimental prairie and surrounding oldfield contained only meadow voles, (Microtus pennsylvanicus). But as community composition changed from hayfield to one of higher quality forbs and grasses, the densities of both the prairie vole, M. ochrogaster, and the white-footed mouse, Peromyscus leucopus increased at the site. I live-trapped small mammals seasonally from fall 1997 through spring 2000, identified each to species and ear-tagged each animal for future identification. No prairie voles or white-footed mice were trapped for the first two years of the study. However, since the winter of 1999, captures of prairie voles consistently comprise 5-9% of all captures, and white-footed mice comprise 20-40% of trapped animals. While the meadow vole has been shown to competitively exclude the deer mouse and the red-backed vole, less is known about the interactions between meadow voles and white-footed mice, or between prairie voles and white-footed mice. Interspecific aggressive behavior has been documented in competitive interactions between meadow voles and prairie voles. It is likely that the Microtus species and P. leucopus are able to coexist and share resources via habitat partitioning in space and time, so that competitive interactions between species are minimized. Habitat is segregated because meadow voles prefer areas of dense vegetative cover, prairie voles tolerate areas with less cover, and white-footed mice typically prefer areas of tall vegetation that provide a vertical structure within the habitat. Segregation in time occurs because white-footed mice forage only at night, while voles are active both day and night. Relative to the original oldfield the prairie plots offer much greater vertical structural complexity, satisfying the habitat requirements of the white-footed mice. And despite its higher relative structural complexity, the prairie plots retain much greater openness than the oldfield, satisfying the habitat preferences of the prairie vole.

Keywords: Microtus, Peromyscus, prairies

This abstract is being presented at: 3:30 PM in session:
ANIMAL ECOLOGY