A role for female ornamentation in the facultatively polygynous mating system of collared flycatchers

In a polygynous mating system, females settling with already mated males often experience low mating success due to the reduced parental contribution of the male. However, there are numerous factors that may still make it advantageous for some females to choose this mating status. Facultative polygyny is believed to be dominated by male advertisement and female choice. Although quality differences and competition among females are increasingly recognized as important determinants of polygynous settlement patterns, the importance of signals of female quality in this mating system is largely unknown. Here we examined the relationship of the white wing patch size (WPS) of female collared flycatchers, a phenotypically plastic and age-dependent ornament, with social mating status, while controlling for settlement date and age. At the population level, monogamous, primary, and secondary females did not differ in WPS. However, the primary female of individual males was more ornamented than the secondary female, and this difference declined with increasing distance between primary and secondary nests. Secondary female ornamentation increased, whereas that of the primary female did not change with nest distance. These results suggest a subtle role for female ornamentation at polygynous mating. Future studies should therefore take into account mating status when assessing the costs and benefits of female signals. Moreover, patterns in quality-indicating female traits may contribute to the explanation of differences in reproductive success among females of different mating status.