Aerial insectivorous bats of the Caatinga: integrated acoustic and voucher specimen analysis in the Chapada Diamantina, Bahia, Brazil

We present the results of an acoustic survey of aerial insectivorous bats in Chapada Diamantina National Park, Brazilian Caatinga. The study complements previously published taxonomic information based on mist-net captures and evaluates the bat fauna associated with semideciduous forests. During 10 sampling nights at a remnant water pool along a seasonally drying river, we recorded 28 species belonging to four families: Emballonuridae, Noctilionidae, Molossidae, and Vespertilionidae. Acoustic monitoring detected 12 species exclusively (42.9%), whereas eight (28.6%) were recorded only through mist-netting, and eight were detected by both methods. Acoustic data provided the first record of Lasiurus villosissimus for the Caatinga and documented regional range extensions for Lasiurus egregius and Myotis riparius. Five species, including one emballonurid, three molossids, and one vespertilionid, showed the highest activity levels. Three functional guilds were represented, with uncluttered-space aerial insectivores dominating the assemblage, largely due to the high representation of Molossidae. This pattern contrasts with previous Caatinga surveys, where high-flying bats were often underrepresented. Our results demonstrate the importance of integrating acoustic monitoring and capture-based methods to improve assessments of bat diversity and community structure in conservation-priority areas and highlight the need for additional acoustic surveys across the Caatinga.