Day-roost selection by rafinesque's big-eared bats (Corynorhinus rafinesquii) in Louisiana forests

Abstract

Availability of bridge roosts is a poorly understood but possibly important component underlying abundance and distribution of the potentially threatened bat Corynorhinus rafinesquii. We analyzed structural characteristics and surrounding habitat of 81 bridges in west-central Louisiana forests to determine which attributes of bridges influenced the selection of roosts by C. rafinesquii. Type of support structure under bridges, material with which bridges were built, proportion of surrounding habitat composed of mature deciduous forest, and road surface of bridges were significantly associated with selection of roost sites. On average, bats tagged with radiotransmitters roosted under bridges 50% of the time and in black gum trees (Nyssa sylvatica) 50% of the time. Preservation of bridges with beam supports and conservation of mature deciduous forest are likely to be important for maintaining populations of C. rafinesquii.