Small Mammals in Prairie Wetlands: Habitat Use and the Effects of Wetland Modifications

Although well documented for other habitat types, small mammal habitat use patterns in prairie wetlands are poorly understood. The distribution of the mammal fauna of South Dakota is also not well known. Because of the lack of information in these areas, evaluation of the impacts of wetland modifications on the resident mammal community is not possible. The objectives of this study were (1) to document the species composition and abundance of small mammal communities inhabiting prairie wetland basins, (2) to determine the effects of small scale habitat modification on small mammals, (3) and to explain local species distribution patterns using habitat measurements. This study was conducted during the summers of 1981 and 1982. Meadow voles (Microtus pennsylvanicus) were the most common small mammal in prairie wetlands, followed by deer mice (Peromyscus spp.), masked shrews (Sorex cinereous), meadow jumping mice (Zapus hudsonius) and northern short-tailed shrews (Blarina brevicauda). Deer mine were more common in modified habitats within wetland basins than in undisturbed habitat. Modification of wetlands tended to reduce the species diversity of small mammals I the modified areas. Local distributions of species seemed to be largely determined by soil moisture. Meadow voles used the wettest habitats and deer mice used the driest. Both species of shrew seemed to use habitats intermediate in terms of moisture between wetlands and uplands