Costs, benefits and the evolution of seasonal plumage colours

Female animals may use conspicuous colours of males to assess their quality as potential mates, if colours come at a cost. This thesis explores the costs of conspicuous colours in a wild bird (the superb fairy-wren), including the need to be cautious to avoid predators, physiological costs and costs of maintaining attractive colours. In addition, this thesis shows colour change between dull and conspicuous plumage in songbirds evolves under strong sexual selection and high predation risk. This work provides insight into sexual selection in animals.