BOWERS ON THE SAVANNA - DISPLAY COURTS AND MATE CHOICE IN A LEKKING WIDOWBIRD

Individual display courts, constructed by lekking male Jackson's widowbirds, Euplectes jacksoni, were studied with respect to female mate choice. The court is a shaped tuft of grass, surrounded by a circular track on which displays and mating are performed. At the base of the tuft there are two cup-shaped recesses. Females sit in front of, and often pluck at, one of these recesses while males display at the opposite side for about 1 min before they approach and attempt to copulate. The vast majority of females visiting courts with experimentally destroyed or impaired recesses stayed shorter than the average time of male approach, whereas visits to improved courts lasted longer than visits to intact courts. All recorded copulations occurred at intact or improved courts. The display court is a weak predictor of male mating success compared to other choice cues such as display rate and tail length, but females may require the court quality to exceed a certain stimulus threshold to accept the male. Court quality correlates positively with male lek attendance and tail length. This paper discusses the implications of the results for sexual selection and considers the possibility that display courts are "external sexual ornaments." From comparative data on breeding behavior in related species, the display court and its associated behaviors are suggested to originate from male nest-initiation and female nest-inspection within an ancestral state of resource-defense polygyny.