title: Carotenoids and egg quality in the lesser blackbacked gull Larus fuscus: a supplemental feeding study of maternal effects.
abstract: Egg quality is a phenotype of, and can profoundly influence fitness in, both mother and offspring. However, the physiological mechanisms that underlie this maternal effect are poorly understood. Carotenoids are hypothesized to enhance antioxidant activity and immune function, and are responsible for the pigmentation of egg yolk. The proximate basis and consequences of this maternal investment, however, have not previously been studied in wild birds. In this supplemental feeding study of lesser black-backed gulls, Larus fuscus, carotenoid-fed females are shown to have increased integument pigmentation, higher plasma concentrations of carotenoids and antioxidant activity, and lower plasma concentrations of immunoglobulins (Igs) in comparison with controls. In turn, carotenoid-fed females produced eggs containing high carotenoid but low Ig concentrations (i.e. passive immunity), whereas control females produced eggs containing low carotenoid but high Ig concentrations. Within-clutch patterns of these resources varied over the laying sequence in a similar manner in both carotenoid-fed and control nests. Our results suggest that carotenoids could be one resource responsible for egg quality maternal effects in birds. We discuss the possible implications of carotenoid-mediated effects on phenotype for fitness in mothers and their offspring.
authors.affiliation: Division of Environmental and Evolutionary Biology, Institute of Biomedical and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK. j.d.blount@udcf.gla.ac.uk
authors.forename: Jonathan D
authors.initials: JD
authors.lastname: Blount
authors.forename: Peter F
authors.initials: PF
authors.lastname: Surai
authors.forename: Ruedi G
authors.initials: RG
authors.lastname: Nager
authors.forename: David C
authors.initials: DC
authors.lastname: Houston
authors.forename: Anders Pape
authors.initials: AP
authors.lastname: Møller
authors.forename: Michael L
authors.initials: ML
authors.lastname: Trewby
authors.forename: Malcolm W
authors.initials: MW
authors.lastname: Kennedy
mesh_terms: D000821:Animal Feed; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D000835:Animals, Wild; D000975:Antioxidants / Q000008:administration & dosage / Q000494:pharmacology; D001717:Birds / Q000276:immunology / Q000502:physiology*; D002338:Carotenoids / Q000008:administration & dosage* / Q000097:blood / Q000494:pharmacology*; D019587:Dietary Supplements; D004530:Egg Yolk / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism; D005260:Female; D007074:Immunoglobulin G / Q000276:immunology; D010063:Ovum / Q000737:chemistry / Q000187:drug effects* / Q000502:physiology; D010641:Phenotype
chemical_list: D000975:Antioxidants; D007074:Immunoglobulin G; D002338:Carotenoids