Plumage Redness and Pigment Symmetry in the House Finch

Abstract

The redness of carotenoid pigmentation has been shown to be an indicator of individual condition. I tested whether the asymmetry of carotenoid pigmentation of male House Finches Carpodacus mexicanus, an indicator of developmental stability, decreases with plumage redness. Consistent with predictions, I found a significant relationship between the symmetry of carotenoid-based crown pigmentation and the redness of body plumage redder plumage was more symmetrical. There was no significant relationship between the symmetry of the outer rectrices and either crown symmetry or plumage redness. The energetic cost of having asymmetrical carotenoid pigmentation is no greater for males with elaborate ornamentation (red plumage) than for males with less elaborate ornamentation (orange or yellow plumage). These observations are consistent with the idea that the magnitude of fluctuating asymmetry of an ornamental trait reflects the phenotypic or genotypic condition of the individual.