Managing for Habitat Heterogeneity in Grassland Agro-Ecosystems Influences the Abundance of Masked Shrews (<i>Sorex cinereus</i>)

ABSTRACT Many agri-environment programs prescribe modified farming practices and provision of heterogeneous habitat types, such as fallow field edges and shelterbelts. The conservation benefit of these actions to biodiversity has been well described. However, the response of insectivorous small mammals to habitat heterogeneity in agro-ecosystems has received little empirical attention. We compared the abundance of the masked shrew (Sorex cinereus) between hayfields and adjacent mesic old-fields in Nova Scotia, Canada. Masked shrews were almost twice as abundant in old-field habitat and were linked closely to abundance of Aranea (spiders), Coleoptera (beetles), and Malacostraca (slugs). This implies that mesic old-field habitat is beneficial to masked shrews and is a likely population source for shrews that occur in hayfields. Because masked shrews consume large quantities of invertebrate prey (that are often considered agricultural pests), we suggest that old-fields are an important habitat to include in agro-ecosystems that should benefit both wildlife and agricultural producers.