The Appalachian Region is known for its extensive tracts of mature hardwood forest and high biodiversity, including that of songbirds. The region is a stronghold for the cerulean warbler, containing about 75 percent of the population. The USGS West Virginia Cooperative Fish and Wildlife Research Unit, in collaboration with the Cerulean Warbler Technical Group, National Council for Air and Stream Improvement, National Fish and Wildlife Foundation, Appalachian Mountains Joint Venture (AMJV), and researchers and managers from universities, state agencies, U.S.