The calling song of male P. podagrosus consists of repetitive series of chirps, each composed of four to six pulses with a mean carrier frequency of 3.8±0.2 kHz and a pulse rate of 205±17 Hz (Fig. 1A). The total duration of the chirp series was highly variable, lasting from a few seconds up to 2 min. The perception of the song is complicated by other cricket species calling at the same time and location in the nocturnal tropical rainforest. In the spectral analysis of such background noise (Fig. 1C), the multiple peaks in the spectrum indicate the different carrier frequencies occupied by these sympatric species. By contrast, the task of detecting the calling song of a conspecific male in a European field cricket (G. campestis) is rather easy because there is no acoustic energy within the relevant frequency range other than that of its calling song (Fig. 1B). [1]
