Display rate by male fairy-wrens (Malurus cyaneus) during the fertile period of females has little influence on extra-pair mate choice

Empirical and theoretical studies have only recently begun to examine how f emales use complex multi-component displays when selecting mates. Superb fa iry-wrens are well suited to the study of female choice because females hav e control over extra-group paternity and cuckold their mates at high rates, while males possess a variety of sexually selected traits. Available evide nce suggests that females base their extra-group mate choice on the timing of male moult into breeding plumage or the onset of display. However, males continue to perform elaborate displays throughout the season, and direct m ost displays to females during their fertile period. We therefore conducted focal observations on fertile females to quantify the frequency of male di splay and used microsatellite genotyping to compare the role of display rat e during the breeding season and the timing of male moult on female mate ch oice. We show that the addition of data on male display rate does not impro ve our ability to predict which males obtain extra-group paternity. The tim ing of male moult into breeding plumage remains the only predictor of male extra-group reproductive success. Nevertheless, we found that males dis pla yed more to females that were unable to select extra-group mates on the bas is of the timing of moult or the onset of display. This raises the possibil ity that there are circumstances when females use display rate to discrimin ate between potential extra-group sires. Overall this study supports the th eoretical prediction that females are more likely to base their mate choice on reliable indicators of male quality such as fixed morphological traits and displays of endurance, in this case an early moult into breeding plumag e and the performance of an elaborate display during the winter, than a fle xible behavioural trait such as display rate during the breeding season.