FOREST EDGE—HIGH OR LOW QUALITY HABITAT FOR WHITE-FOOTED MICE (PEROMYSCUS LEUCOPUS)?

Abstract

Based on evidence of negative relationships between forest fragment area and mouse density, earlier studies suggested that forest edge might be high quality habitat for white-footed mice (Peromyscus leucopus). However, we have found lower densities of this species and higher prevalence of parasitism near woodland edges. To examine the overall effect of edge habitat, we measured food availability (tree seeds and litter invertebrates), reproductive effort, and risk of predation along edge-to-interior gradients in eastern deciduous forests. We also compared woods adjacent to restored prairies to woods adjacent to agricultural fields to determine if the type of habitat adjacent to the edge affected these factors. Results showed slightly higher production of tree seeds in forest interior but no edge-to-interior pattern in abundance of invertebrates. Reproductive effort did not differ between edge and interior either. Risk of predation, however, showed a significant increase with proximity to the woodland edge. Type of adjacent habitat did not consistently affect factors determining edge-to-interior patterns. Mass of tree seeds differed little between woodland edges adjacent to different habitats in spring but was greater adjacent to agriculture in fall. Invertebrate abundance did not differ between woodland edges with different adjacent habitats. Risk of predation was higher at edges adjacent to restored prairies than at edges adjacent to agricultural fields. We conclude that forest edges are generally lower quality habitat than forest interior for white-footed mice because of increased predation, and that relatively natural edges are likely to have higher risk of predation than anthropogenic edges.