Females have a perceptual bias towards the first call of a sequence. The males have evolved tomake call-timing adjustments to their own free-running call period in response to competitors in their immediate environment. This is a short segment of a recording of the advertisement calls of two males. The frogs were approximately four feet apart; the microphone was held equidistant between the two. In this trace, one frog delays his call until he becomes the leading caller. As this calling bout continued, the other frog subsequently adjusted his timing to become the first caller; this pattern repeates througout the recording. The original audio can be found by clicking on the title of this post. Our next step is a stereo recording with two microphones as the live effect is striking.
