How Interacting Multiple Male Sexual Signals Influence Female Choice in the Great Bowerbird

Male courtship displays commonly involve multiple sexual signals. While there has been considerable interest in female choice for male multiple signals, few studies have investigated how these signals interact. We analyzed courtship behaviours of male Great Bowerbirds Chlamydera nuchalis, which include both acoustical elements, including ticking sounds of three types (SS, MS and LS), and locomotive elements, including dancing around the bower. Our results show that the ticking sounds played an important role in female choice. Males that uttered more LS sounds (louder and longer than the other two types) attracted more females, which suggests that intense display enhances mating success. In addition, males uttering more LS type calls had a larger bower, which suggests that a large bower provides females a safe protection against male's vigorous display and that the male can perform display more intensely. These results show that the multiple signals interacted with each other.