Behavioral, Seed Preference and Habitat Selection Experiments with Two Sympatric Peromyscus Species

Abstract

The woodland white-footed mouse Peromyscus leucopus noveboracensis cooccurs with the prairie deermouse P. maniculatus bairdi in old fields and prairies of southern Wisconsin. In order to examine possible mechanisms of this coexistence, fieldcaught individuals of both species were brought into the laboratory for testing. In a seed preference test in which mice were offered two species of old-field grass seeds and two species of native prairie grass seeds, all the mice preferred the old-field grass seeds. Neither species favored either habitat (field or woods) for activity during two 0.5-hr observation periods or for foraging. However, P. m. bairdi removed significantly less food from the woods habitat than did P. 1. noveboracensis and there was a significant difference in preferred nest location, with P. m. bairdi nesting primarily in the field and P. 1. noveboracensis in the woods. In 20 paired behavior trials, P. m. bairdi was dominant in two, P. 1. noveboracensis in 12, and there was mutual avoidance in six. The results suggest that interference competition may, in part, account for the distribution patterns of these species.