We examined whether male plumage coloration signals parental quality in the American Redstart (Setophaga ruticilla), a highly ornamented, migratory warbler. We measured the relationship between both adult male arrival date and phenotype (morphology, melanin- and carotenoid-based plumage), and parental care levels of both parents. Males with brighter flank feathers made more visits to the nest and spent more time at the nest, consistent with the ‘good-parent hypothesis’. Female parental care (number of visits) was negatively correlated with intensity of red of her mate’s tail feathers and positively associated with her mate’s parental effort. These data indicate offspring of brighter males receive more care from both parents. Our results suggest carotenoid-based plumage traits of male American Redstarts may have an important role in intersexual signaling, and add to our understanding of the evolution of multiple ornaments.
