Figure 6.

Calling rates for the four different kinds of bouts for the four July chorus nights at the two chorus sites. (A) Rate of call alternation events. Call alternation was significantly more likely to occur between clusters compared to within clusters on all four nights. (B) Rate of call overlap events. The pattern of call overlap differed significantly between clusters compared to within clusters in all choruses. Call overlap was more likely to occur between clusters. (C) Rate of note alternation events. Note alternation occurred exclusively within clusters at pond 1 (7∕5∕05), so no statistical test could be performed on these data. At the other three choruses, note alternation was significantly more likely to occur within clusters than between clusters. (D) Rate of note overlap events. Note overlap was observed only within clusters and never between clusters at pond 1. At the other choruses, note overlap occurred significantly more often within clusters than between clusters.