Competition and Habitat Selection in a Forest-Floor Small Mammal fauna

Abstract

In a study of habitat exploitation in a forest-floor small mammal community, habitat and population data for Peromyscus leucopus (white-footed mouse). Ochrotomys nuttalli (golden mouse) and Tamias striatus (eastern chipmunk) were collected. Using multiple regression analysis, the effect of habitat selection and competition on the local distributions of these species during 3 seasons were estimated. Each of the partial regression coefficients relating the density of an independent species to the density of the dependent species is negative. Competion (i.e., mutual inhibition) is pervasive among these species. Competitive ability and habitat selectivity both increase in the order Peromyscus-Tamias-Ochrotomys. Peromyscs is a poorly competitive habitat generalist, Ochrotomys is a strongly competitive habitat specialist and Tamias is intermediate in both respects. The competitive hierarchy is stable between seasons. Conclusions from previous studies of this small mammal community and the design of experiments to further clarify the mode and consequences of interaction between these species were discussed.