Occurrence and Habitat Use of Bats in Central Alabama Forests

Abstract

Limited information is available on the relationship between characteristics of landscape and seasonal use of habitat for forest-dwelling bats in central Alabama. This study was designed to clarify these relationships and to provide information for managers charged with restoring or maintaining native habitat. Bats were surveyed in randomly selected plots on lands administered by the U.S. Fish and Wildlife Service. Standard sampling techniques were used, primarily bat detectors and mist nets. Land use, type of land-cover, and vegetative and physical features of each plot were sampled and recorded. Occupancy analysis was used to examine use of habitat and distribution of species. The following taxa were detected and identified: Tadarida brasiliensis, Eptesicus fuscus, Lasiurus borealis, L. cinereus, L. seminolus, Nycticeius humeralis, Perimyotis subflavus, Myotis grisescens, and various unidentified species of Myotis. Temperature was the best indicator for detection for all groups and species. Species with echolocation frequency ≤29 kilohertz (kHz) selected open habitats, specifically rivers, streams, and fields. Bats with echolocation frequencies 30-39 kHz selected open habitats and showed a strong affinity for certain types of forested habitats. The group used pine stands and hardwood stands, but did not select for mixed forest stands. Use by species with echolocation frequencies ≥40 kHz was greater in open habitats as opposed to closed forests. Individual species showed varied probability of use to key types of habitat, type of forest, structure of forest, and slope.