Mating-Behavior and Sexual Competition in the Regent Bowerbird Sericulus chrysocephalus

Abstract

Male Regent Bowerbirds Sericulus chrysocephalus build small, meagrely decorated avenue bowers for courtship displays and copulation. In order to study the social behaviour of males and females at bowers, in particular the patterns of female visits and male interactions, bower activities were monitored for 1516 hours at 33 active bowers in the Sarabah Range, south-eastern Queensland. Adult males spent only 3.2% of daylight hours in bower attendance. Most courtship displays (96.3%, n = 54), including all successful displays which led to a copulation, were observed after a female had been escorted to a bower by its owner. This suggests that the initial interactions between males and females take place in the canopy. The duration of female visits was correlated with a measure of the overall quality of the bower construction, but not with numbers of decoration objects. Bower destruction and decoration stealing by intruding males occurred at a mean rate of 0.034 and 0.022 times per h, respectively. Bower damage caused by intruders frequently led to the abandonment of a bower by its owner who changed his bower location. Similarities to and differences from other bowerbird species and the position of the genus Sericulus in bowerbird evolution are discussed.