Echolocation Calls of the Eleven Insectivorous Bats of Taiwan

Abstract

Insectivorous bat emits ultrasound and listens to its echo in flight, the so-called echolocation call, to detect surrounding and to identify prey. Information on its patterns of different species is useful for the inventory survey, particularly when capturing is difficult. There are over 30 species of insectivorous bats in Taiwan, but such information was scarce. This study was intended to collect basic characters of echolocation calls of common insectivorous bats in Taiwan to establish their reference database for the intra- and inter-species identification. In March 2005 to November 2006, 249 individuals of 11 species of bats were caught with harp traps and mist nets around Taiwan and on the Kinmen Island. Ten parameters of the echo pulses were recorded and analyzed with the AnaBat system bat detector. Among these species Rhinolophus monoceros and Hipposideros terasensis emitted constant frequency (CF) type echo-calls; whereas the other 9 species had frequency modulated (FM) type echo-calls. For the former, the mean frequency (Fmean) and the constant part of the CF calls were 111.14 ± 2.57 kHz, respectively, for R monoceros, and 67.56 ± 1.53 kHz for H. terasensis. For the latter the mean frequency was 50.40 ± 3.91 kHz for Pipistrellus abramus, 45.41 ± 5.26 kHz for Arielulus torquatus, 46.91 ± 3.96 kHz for Scotophilus kuhlii, 34.55 ± 4.86 kHz for Eptesicus serotinus horikawai, 51.30 ± 8.86 kHz for Miniopterus schreibersii, 86.84 ± 10.30 kHz for Murina puta, 54.77 ± 3.19 kHz for Myotis latirostris, 54.05 ± 4.65 kHz for Myotis sp.2, and 57.55 ± 4.46 kHz for Myotis sp.3. Jamming avoidance responses to echolocation calls were observed in some of the colonies of P. abramus and S. kuhlii. Dialects were found among colonies of Mi. schreibersii.