Roost-site Selection by Eastern Red Bats (Lasiurus borealis)

(Uploaded by Plazi for the Bat Literature Project) To investigate natural roost-site selection by eastern red bats (Lasiurus borealis) in an urban area we equipped 12 bats with radio-transmitters and located them at 75 individual roost sites in central Illinois from 16 July to 30 September 1996. Bats used a diversity of roosts including mature trees, leaf litter, dense grass and the shingles of houses, but the majority of roosts (89%) were in the foliage or on the trunks of large deciduous trees (Ͼ45 cm dbh). Sweetgum (Liquidambar syraciflua) and oaks (Quercus spp.) were commonly used. Most roosts were located in foliage, Ͼ5 m above the ground, within 1.5 m of the edge of the crown and with few branches beneath to obstruct flight paths. Red bats showed fidelity to roost sites within a small geographic area, but not to particular roosts. Individuals rarely used the same roost on consecutive days, but 82% of roosts used on successive days were within 100 m of each other. In the cornbelt region of the Midwest, where forests have been extensively cleared and fragmented, large urban trees provide important roosting habitat for red bats.