Roost sites of the silver-haired bat (Lasionycteris noctivagans) in the black hills, south Dakota

We investigated the roosting ecology of silver-haired bats (Lasionycteris noctivagans) in the Black Hills of western South Dakota. Using radiotelemetry, we located 39 roosts, 10 of which were maternity aggregations contain- ing 6 to 55 bats. The roosts were mostly in ponderosa pine (Pinus ponderosa) snags that averaged 39 cm diameter at breast height. Solitary bats preferred roosting under loose bark or in crevices in trees, regularly moving among trees. All maternity aggregations were found in tree cavities, primarily those created by woodpeckers. Roost trees were located in patches of forest with relatively high snag densities, about 21 snags/ha. This study suggests that snags play an important role in maintaining silver-haired bat populations in ponderosa pine ecosystems.