title: Carotenoid-based colour expression is determined early in nestling life.
abstract: Carotenoid-based colours are widespread in animals and are used as signals in intra- and interspecific communication. In nestling birds, the carotenoids used for feather pigmentation may derive via three pathways: (1) via maternal transfer to egg yolk; (2) via paternal feeds early after hatching when females are mainly brooding; or (3) via feeds from both parents later in nestling life. We analysed the relative importance of the proposed carotenoid sources in a field experiment on great tit nestlings ( Parus major). In a within-brood design we supplemented nestlings with carotenoids shortly after hatching, later on in the nestling life, or with a placebo. We show that the carotenoid-based colour expression of nestlings is modified maximally during the first 6 days after hatching. It reveals that the observed variation in carotenoid-based coloration is based only on mechanisms acting during a short period of time in early nestling life. The experiment further suggests that paternally derived carotenoids are the most important determinants of nestling plumage colour.
authors.affiliation: Institute of Zoology, Evolutionary Ecology Division, University of Bern, Baltzerstrasse 6, 3012 Bern, Switzerland. patrick.fitze@esh.unibe.ch
authors.forename: Patrick S
authors.initials: PS
authors.lastname: Fitze
authors.forename: Barbara
authors.initials: B
authors.lastname: Tschirren
authors.forename: Heinz
authors.initials: H
authors.lastname: Richner
mesh_terms: D000222:Adaptation, Physiological; D000821:Animal Feed; D000818:Animals; D002338:Carotenoids / Q000008:administration & dosage*; D003116:Color; D019587:Dietary Supplements; D005241:Feathers / Q000502:physiology*; D005260:Female; D009425:Nesting Behavior; D010858:Pigmentation; D020308:Songbirds / Q000502:physiology*
chemical_list: D002338:Carotenoids