Figure 3
Timing parameters in male chorusing and female preference.
(A) Call delay histograms of representative males from 2 populations (Col de Chioula, Font Romeu; Fig. 4A). The numbers of calls produced during 50-ms bins beginning at the onset of a synthetic call stimulus broadcast at random intervals are shown. The post-stimulus delay of the earliest of the male’s 40 calls following inhibition is equivalent to m in Fig. 1. (B) Minimum post-stimulus call delay, m, for each of 8 males tested via playback in the 2 populations. A male’s m is determined as the average of his 3 shortest delays. The population’s m is the average of the individual male values. (C) Index of preference by females in the 2 populations for the leading of 2 synthetic call stimuli broadcast in close succession. For a given population, the maximum leader-follower call separation at which the index remained ≥50% of the highest index value observed across all call separations was designated as f; in all but one population this highest index value was significant (Ho: index = 0.0; 1-tailed sign test, α = 0.05; each female that preferred the leader in >50% of trials was labelled ‘+’ and labelled ‘−’ if < 50%; the sign test was performed on the labels of all females tested for responses to a given call separation). *Index of preference >0.0.
