Roost Characteristics of Hoary Bats in Arkansas

—We radiotracked nine hoary bats (Lasiurus cinereus) and characterized 12 roosts during late spring and early summer in the Ouachita Mountains of central Arkansas. Hoary bats generally roosted on the easterly sides of tree canopies in the foliage of white oaks (Quercus alba), post oaks (Q. stellata) and shortleaf pines (Pinus echinata). Roost heights averaged 16.5 6 2.2 m and all roost trees were .21 cm dbh and were taller and greater in diameter than random trees. Roost sites averaged 7.7 m/ha basal area (BA) of overstory pines, 4.4 m/ha BA of overstory hardwoods and 80% canopy cover. Roost sites had a greater number of understory stems than random sites. All roosts were located in stands dominated by mature (overstory .50 y old) overstory trees. Seven roosts were in relatively unmanaged mixed pine-hardwood and hardwood stands .50 y old and four roosts were in mature mixed pine-hardwoods stands that recently had been thinned and subjected to prescribed burning; one additional roost was located outside the study area in a mature shortleaf pine stand that was thinned approximately 10 y previously. Although not abundant during early summer in Arkansas (only 3% of our captures), hoary bats were confirmed to reproduce in the region.