Habitat Preferences of Five Sympatric Species of Long‐Tailed Sherws

Abstract

Long—tailed shrews of 5 species were captured throughout four years at a single 60—acre at 9,700 ft elevation in western Larimer County, Colorado. Interspecific differences in the proportions of captures in 3 main habitats, sedge marsh, subalpine forest, and clear—cut forest were significant. All species except one, Sorex palustris, were captured in all three types however. S. palustris was taken only adjacent to bodies of water. Sorex cinereus and Sorex vagrans were captured with the greatest relative frequency in marsh situations. The frequency of captures of the former species in the clear—cur habitat was proportionally lower than for the latter species. Sorex nanus and Microsorex hoyi were taken with high frequency in the forest. S. nanus was taken with the greatest frequency of any species in the clear—cut area and also at the greatest mean distance from permanent surface water. M. hoyi was captured more frequently than any other species at sites intermediate in character between marsh and forest. It was captured much less frequently in the clear—cut area and more frequently in the marsh than S. nanus but less frequently in the marsh than either S. cinereus or S. vagrans. Indices of relative abundance of S. cinereus and S. vagrans synchronously declined sharply in 1963 from high points in 1962 but increased again in 1964. Indices for S. nanus and M. hoyi remained approximately uniform throughout the four years.