ECHOLOCATION CALLS AND FIELD IDENTIFICATION OF THE EASTERN PIPISTRELLE (IPISTRELLUS-SUBFLAVUS, CHIROPTERA, VESPERTILIONIDAE), USING ULTRASONIC BAT DETECTORS

In the field, Pipistrellus subflavus produces 5-ms-long, broadband, ec holocation calls when flying in search of airborne prey. These calls t ypically have two strong harmonics, the first with energy between 35 a nd 19 kHz and the second with energy between 70 and 38 kHz. To an obse rver with two narrowband bat detectors, one tuned to 40 kHz and the ot her to 20 kHz, echolocation calls of P. subflavus are distinct from th ose of other sympatric species in the northern part of its geographic range.