title: Antioxidants in the egg yolk of a wild passerine: differences between breeding seasons.
abstract: Carotenoids and fat-soluble vitamins play crucial roles in several physiological processes. Yolk carotenoid composition may be influenced by the bird's dietary intake and by the possible discrimination during carotenoid metabolism. Information regarding the pigment composition of passerine eggs is very limited. In the present 2-year study, we determined the carotenoid and vitamin concentrations and the percentage profile of carotenoid components in collared flycatcher (Ficedula albicollis) eggs. The major carotenoid was lutein in both years, followed by cis-lutein, zeaxanthin and beta-carotene as other significant components. Carotenoid concentration was higher in 2000 than in 2001. As caterpillar abundance and ambient temperature was lower in 2001 than in 2000, we suggest that the decreased availability of carotenoid-rich resources and the elevated antioxidant demand of the female restricted the carotenoid allocation to the eggs. Our study is the first to indicate that the concentration and profile of yolk carotenoids may considerably vary in the same wild bird population between breeding seasons with different environmental conditions. Compared to other birds, the yolk of this species was relatively rich in vitamins A and E. Vitamin E concentration was positively correlated with total carotenoid concentration, which may be beneficial for the nestlings as these antioxidants synergistically provide better protection.
authors.affiliation: Behavioural Ecology Group, Department of Systematic Zoology and Ecology, Eötvös Loránd University, Pázmány P. sétány 1/C, H-1117 Budapest, Hungary. harrita@freemail.hu
authors.forename: Rita
authors.initials: R
authors.lastname: Hargitai
authors.forename: Zoltán
authors.initials: Z
authors.lastname: Matus
authors.forename: Gergely
authors.initials: G
authors.lastname: Hegyi
authors.forename: Gábor
authors.initials: G
authors.lastname: Michl
authors.forename: Gyula
authors.initials: G
authors.lastname: Tóth
authors.forename: János
authors.initials: J
authors.lastname: Török
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000032:analysis*; D001947:Breeding; D002338:Carotenoids / Q000032:analysis; D004032:Diet; D004530:Egg Yolk / Q000737:chemistry*; D005247:Feeding Behavior; D007915:Lepidoptera; D014975:Lutein / Q000032:analysis; D010063:Ovum / Q000737:chemistry; D046109:Passeriformes; D012621:Seasons; D014815:Vitamins / Q000032:analysis; D024341:Xanthophylls / Q000032:analysis; D065146:Zeaxanthins; D019207:beta Carotene / Q000032:analysis
chemical_list: D000975:Antioxidants; D014815:Vitamins; D024341:Xanthophylls; D065146:Zeaxanthins; D019207:beta Carotene; D002338:Carotenoids; D014975:Lutein