Casey Devine-Rosser; Christopher Newport University; Dept. of Organismal & Env. Biology, 1 Avenue of the Arts, Newport News, VA, 23606; (757) 630-6187; casey.devinerosser.13@cnu.edu; Rick E. Sherwin, Jason Williams, Linda S. DeLay, Rick E. Sherwin
There has been growing concern regarding the long-term viability of bat colonies and even species that habitually roost in abandoned mines. Initially, managers were concerned that the concentration of large numbers of individuals in the same location leaves them susceptible to vandalism, abandoned mine reclamation, and/or stochastic perturbations. The simplest solution to this problem has been to install bat compatible closures over entrances of biologically important features, while sealing those which are biologically insignificant or cannot be safely secured. To date, thousands of bat compatible closures have been installed in the western United States and tens of thousands of dangerous abandoned mines have been permanently sealed. Despite the apparent success of these efforts, there is increasing debate regarding the acceptability by bats of different gate designs, construction materials, and structural enhancements. In recent years anecdotal observations that bats reject gates which include culverts (installed to maintain the integrity of the portal and structural support for the gate) have been used to suggest that culverts will not be used by bats. In this study we will present data from our long term monitoring of colonies of Townsend's big-eared bats in abandoned mines throughout the western U.S. This talk will focus on the short and long term response of bats to traditional bat gates compared with gates installed in culverts. Response variables include types of use (pre and post closure), numerical and/or behavioral changes, and spatio-temporal changes in dynamics of roost use. We compare sites closed with traditional bat gates and gates which include culverts in areas impacted by large scale abandoned mine reclamation programs (i.e., all mines either gated or closed), and in areas where the only treatments are the gates (i.e., no concurrent closures of other mines in the landscape).
Ecology and Conservation of Bats I