Fig. 4: Female vocal response during the playback experiment in the nest box.

Female response is shown as the proportion of song bouts where females produced at least one copulation solicitation call, in relation to the total number of bouts played while the female was inside the nest box. For the same 13 female subjects and for 442 bouts, a shows that female vocal response was significantly higher during the Song treatment than during the Silence treatment. Box and whisker plots showing median, upper and lower quartiles and 1.5 interquartile range. Points overlaid represent individual females, as the proportion of bouts with vocal response out of all bouts presented. b The significant, positive correlation between female vocal response and vocal consistency of playback song. In (b), points represent the proportion of bouts with vocal response out of all song bouts played for each song type during each trial. Black lines connect the response of the same female to both song types presented within the same trial. The red line represents the predicted values derived from the model, with the 95% CI interval in the pink shaded area. Source data are provided in Supplementary Data 2.