The Service defines suitable NLEB roost tree as any tree ≥3 inches in diameter (at breast height) with cracks, crevices, exfoliating bark, and/or cavities/hollows that is within 1000 feet of forested/wooded habitat.
Although NLEB roosts are often dead or dying trees, live trees with defects are also commonly used. NLEB have been reported to use over 35 roost tree species, but deciduous species are most frequently selected. Maternity roosts (roost trees used by reproductive female bats and their young) are typically higher-quality roosts (i.e., large-diameter, tall trees with peeling bark and/or notable defects and adequate solar exposure); however, compared to sympatric Indiana bat roosts, NLEB roosts (even maternity roosts) are often smaller, shorter trees with a higher degree of canopy cover and are more likely to be living.