Figure 1: Sonagrams of typical echolocation and communication calls from two subspecies of greater horseshoe bats.

R. f. tragatus (two individuals in a and b, respectively) and R. f. nippon (two individuals in c and d, respectively). Individual resting frequencies (RF2) of echolocation pulses (marked by ‘E’) given for each bat and indicated by pink hatched lines. Note the large frequency differences between RF2 and the second harmonic of communication calls, which are indicated as numbers (kHz) above the white vertical pairs of arrows.