Osmond, Matthew Miles, Reudink, Matthew W., Germain, Ryan R., Marra, Peter P., Nocera, Joseph J., Boag, Peter T., and Ratcliffe, Laurene M. 2013. "Relationships between carotenoid-based female plumage and age, reproduction and mate colour in the American Redstart (Setophaga ruticilla)." Canadian journal of zoology 91 (8):589-595. https://doi.org/10.1139/cjz-2013-0017
Most studies investigating the function and evolution of ornaments have focused on males. Variation in ornaments may also reflect individual quality and convey information in females. We examined correlations between female plumage colour and reproductive variables in the sexually dichromatic songbird, the American Redstart (Setophaga ruticilla L., 1758). Female American Redstarts display yellow, carotenoid-based plumage patches on their tails, wings, and flanks. Using reflectance spectrometry we quantified brightness (feather structure) and 'yellowness' (hue/chroma) of tail and flank feathers to examine whether female plumage colour varies with age, reproductive success, parental care, and the plumage colour of mates. Female plumage varied with age, with adult (after second year) females having brighter tail feathers than first-year females. We failed to find a relationship between female plumage colour and pairing or first-egg dates. However, adult females with brighter tails visited their nests less fr...
