Biologists since Darwin have sought to understand how extreme male display traits function. Among species with exaggerated male display, bowerbirds are especially well suited for analysis because (1) their unique display allows experimental manipulation of display components, (2) patterns of display differ greatly in closely related species, and (3) they are one of the few kinds of animals for which the details of female choice are well known. Dr. Borgia will develop a biochemical phylogeny of bowerbirds based on comparisons of mitochondrial DNA. In the field, he will observe display and experimentally manipulate conditions under which it occurs for four species. This comparative information can be used (1) to reconstruct the historical sequence by which complex display traits evolved and (2) to carry out novel tests of hypotheses about the operation of female choice. This project is the first attempt to use comparisons within a group of related species to evaluate recent models for the evolution of female choice and extreme male display. This study should help provide critical information for developing a general model for mate-choice patterns in animals. Such knowledge can have important economic applications in species preservation, pest control, game management, and animal breeding.
