Oscillogram, spectrogram, and power spectrum showing the highly modulated advertisement call (A) and the almost non frequency modulated alarm call. (B) Some acoustic parameters are depicted. FpeakS is the peak frequency of the start and F0S is the fundamental frequency of the start. Figure produced in BatSound Pro 3.31 (Pettersson Elektronik AB, Uppsala, Sweden) according to Leliveld and colleagues . See Additional files 3 and 4 for more information.