Figure 1

Courtship song and putative courtship song rhythms. (a) An example of a segmented single recording is shown at multiple scales, from 100 s to 100 ms. Each subsequent clip is derived from the region highlighted with the grey bar. A single inter-pulse interval (IPI) is illustrated in the 100 ms clip. (b) The IPI varies over an order of approximately two on a short timescale, even within a single pulse train. The example song trace is shown above and the IPI values are shown below. (c) The IPI displays similar high variation over a 5 min interval. The song trace is shown above and the IPI data below. (d, e) Examples of KH cycles produced by D. melanogaster (d) and D. simulans (e) reported in reference [6].