Effects of recording media on echolocation data from broadband bat detectors

Bat detectors are an important tool for ecological studies of bats. However , quality and quantity of data may be affected by the devices used to recor d the output from the detector. We compared recordings of bat activity from audiocassette recorders and computers. Numbers of calls/hour, passes/hour, identifiable passes/hour, and feeding buzzes/hour were similar (all Ps >0. 1) among recording devices. All call characteristics, except for the minimu m frequency and characteristic frequency, differed (P <0.05) between tapes and computers. Species identification using discriminate function analysis was less reliable with tape data than with computer data, particularly when the model built with computer-recorded reference calls was tested with tap e-recorded calls. Therefore, we suggest that when tape recorders are used f or field recording, they also are used to record reference calls.