Use of vocal signatures for the inventory of free-flying Neotropical bats

An ongoing study is being conducted to test the efficacy of the Anabat II d etector and analysis system in obtaining reliable vocal signatures for the identification of non-phyllostomid species of bats. We sampled a wide range of elevations and associated habitat rr pes throughout Belize. Anabat prov ides an instantaneous output of echolocation call structure with a laptop c omputer. Select sequences can be saved directly to the hard drive, avoiding extraneous noise and sound distortion commonly associated with rape record ers. To dare, 18 of the 37 species known or expected to occur in the study region were identified by recognizable differences in the time-frequency ch aracteristics of echolocation calls. In general, each family is recognizabl e by call structure patterns and species readily separated by frequency ran ge parameters. Species that commute or forage at high altitudes are nor sus ceptible to capture bur are conspicuous by acoustic sampling. Further work is needed to determine limitations of the equipment, establish better sampl ing procedures, and develop a comprehensive library of vocal signatures inc orporating the range of variation inherent in each species. As this work pr ogresses, we predict the addition of hitherto unknown species occurring wit hin the study region.