The Roosting Ecology of the Silver-Haired Bat Lasionycteris noctivagans in the Black Hills of South Dakota

Abstract

The silver-haired bat Lasionycteris noctivagans occurs widely across North America (Kunz 1982a) at highly variable densities (Barbour and Davis 1969). Still, little is known of its ecology and behavior, especially of its summer roosting habits (Kunz 1982a). Summer roost sites have been alledged to be mostly in trees, but few reliable records are available (Kunz 1982a). Barclay et al. (1988) searched trees in Manitoba and found silver­haired bats roosting under folds of loose bark during the migration period. Likewise, Parsons et al. (1986) and Novakowski (1956) each reported finding a small maternity colony of silver-haired bats in hollow trees in Canada. Studies in the northwestern United States have suggested that silver-haired bats occur more frequently in late-successional forest dominated by trees over 200 yr old than in early seres (Perkins and Cross 1988, Thomas 1988). This association has been attributed to the presence of high concentrations of standing dead trees, some of which have exfoliated bark, cracks in the wood, and cavities excavated by birds sites that may be preferred by bats for roosting (Perkins and Cross 1988, Thomas 1988). To better understand roost selection and habitat requirements of silver-haired bats, we investigated the roosting ecology of this species in the Black Hills of South Dakota.