Physiological conditions and genetic controls of phaeomelanin pigmentation in nestling barn swallows

Lay Summary Many animals possess conspicuous traits that appear to be nonfunctional for survivorship but are used in communication. Such traits often provide information about the quality of the possessors to others. However, although empirical studies have found many signal traits that are associated with individual quality, the underlying mechanisms remain to be understood. In this study, we showed that high-quality individuals could produce colourful plumage without increasing oxidative stress through genetic control.