Fig. 2From: Trade-offs in the production of animal vocal sequences: insights from the structure of wild chimpanzee pant hootsThe relationship between call duration and the number of calls in the four phases of a pant hoot and the entire sequence. a – introduction, b – build-up, c – climax, d – let-down, e – entire pant hoot. Black line represents regression line; circles represent data pointsBack to article page