Contribution of acoustic methods to the study of insectivorous bat diversity in protected areas from northern Venezuela

We present the results of an acoustic survey of aerial insectivorous bats c onducted in four protected areas in northern Venezuela. These areas represe nt localities where the taxonomic composition of the bat communities was re latively well known. We conducted field surveys using the Anabat II detecto r and analysis system. We compared acoustic inventories with previous lists obtained with conventional sampling methods (principally mist nets). We id entified 30 species acoustically (representing 15 genera of the families Em ballonuridae, Noctilionidae, Mormoopidae, Vespertilionidae, and Molossidae) on the basis of vocal signatures. Nineteen of these were verified by captu re and subsequent recording of released animals; the remainder were identif ied by comparison with verified vocalizations from other localities. An add itional 11 unidentified but distinct taxa were recorded and are referred to here as 'sonotypes' (based on similarities in call structure to known spec ies) representing eight genera of the families Emballonuridae, Vespertilion idae, and Molossidae. The short-term acoustic surveys nearly equaled or exc eeded the known species richness at three of the four localities, and added two to nine species to previous lists from all locations; many of these ba rs correspond to taxa difficult to detect with conventional capture methods .