Dietary overlap in sympatric populations of Pygmy Shrews, Sorex hoyi, and Masked Shrews, Sorex cinereus, in Michigan

Abstract

Summer (15 May - 20 August) foods of 29 Pygmy Shrews (Sorex hoyi) and 31 Masked Shrews (Sorex cinereus) were examined in a seven bog/peatland habitats in northern lower Michigan. Ants accounted for 45.5% and 50% of the prey items found in the stomach and intestinal tracts of Pygmy and Masked shrews, respectively. Non-formicid Hymenoptera, Arachnida, Coleoptera, and Lepidoptera larvae made up the remainder of the diet of both shrew species. Both Pygmy and Masked shrews seemed to prefer prey less than 5 mm in total body length. Data from this study indicate that there is a high degree of dietary overlap between sympatric populations of Pygmy Shrews and Masked Shrews in Michigan.