No evidence for an adaptive role of early molt into breeding plumage in a female fairy-wren

The evolution of ornaments as sexually selected signals is well understood in males, but female ornamentation remains understudied. Fairy-wrens offer an excellent model system, given their complex social structure and mating systems, and the diversity of female ornamentation. We investigated whether early molt into ornamental breeding plumage plays an adaptive role in females of the monogamous purple-crowned fairy-wren Malurus coronatus, the only fairy-wren known to have female seasonal plumage. Using six years of monitoring, we found that timing of female molt was similar to males, but there was no evidence for assortative mating. Like males (previous study), older and dominant individuals acquired their breeding plumage earlier; however, in contrast to males, early molt did not seem to be costly since unfavourable environmental conditions or previous reproductive effort did not delay molt. Early female molt was not associated with any indicator of reproductive quality nor did it attr...