Female and male plumage color is linked to parental quality, pairing, and extrapair mating in a tropical passerine

Abstract

Abstract Sexual selection has been proposed to drive the evolution of elaborate phenotypic traits in males, which often confer success in competition or mating. However, in many species, both males and females display such traits. Studies examining how selection acts on both sexes are scarce. In this study, we investigated whether plumage ornamentation is sexually selected in females and males lovely fairy-wren Malurus amabilis, a cooperatively breeding songbird. We found that female and male plumage color was correlated with parental quality but not with individual quality or survival. We also found evidence of positive assortative mating based on plumage color. Microsatellite analyses of paternity indicated that the lovely fairy-wren has high levels of extrapair paternity (EPP), with 53% of offspring (in 58% of broods of 57% of females) resulting from extrapair (EP) mating. Female and male plumage color did not predict reproductive success or the proportion of EP offspring in their own nest, but less colorful males obtained higher EPP when paired with more colorful females and gained overall higher total paternity (own nest and other nests). We argue that plumage color may be under sex-specific selection, highlighting the importance of looking at both sexes in studies of sexual selection and ornament evolution. The current findings together with the previous study suggest that plumage color in female and male lovely fairy-wrens appears to be an honest signal relevant in both intrasexual and intersexual competition contexts.