Fig. 6. Upper panels: auto-correlograms illustrate signal patterning of a single fish for (A) Type 2 chirps (N=22), (B) AFRs (N=31) and (C) Type 2 chirps and AFRs (N=18). Means for all fish for all trials in which fish produced 10 or more signals are plotted, except in the case of Type 2 chirps where only male counts are used in the analysis. The horizontal line denotes the null distribution: the distribution expected if signals are produced at random. Lower panels: bin-by-bin statistical analysis of the correlograms. The fraction of individual fish in which the corresponding bin height is either greater than expected by chance (P>0.95, black line) or less than expected by chance (P<0.05, grey line).