Antioxidants in eggs of great tits Parus major from Chernobyl and hatching success.
Antioxidants are powerful protectors against the damaging effects of free radicals that constitute the inevitable by-products of aerobic metabolism. Growing embryos are particularly susceptible to the damaging effects of free radicals produced during rapid growth, and mothers of many species provide protection against such damage by allocating antioxidants to their eggs. Birds living in radioactively contaminated areas use dietary antioxidants to cope with the damaging effects of radiation, but females also allocate dietary antioxidants to eggs, potentially enforcing a physiological trade-off between self-maintenance and reproductive investment. Here we tested whether female great tits Parus major breeding in radioactively contaminated study areas near Chernobyl allocated less dietary antioxidants to eggs, and whether such reduced allocation of dietary antioxidants to eggs had fitness consequences. Concentrations of total yolk carotenoids and vitamins A and E were depressed near Chernobyl compared to concentrations in a less contaminated Ukrainian study area and a French control study area, and all antioxidants showed dose-dependent relationships with all three dietary antioxidants decreasing with increasing level of radiation at nest boxes. These effects held even when controlling statistically for potentially confounding habitat variables and covariation among antioxidants. Laying date was advanced and clutch size increased at nest boxes with high dose rates. Hatching success increased with increasing concentration of vitamin E, implying that hatching success decreased at boxes with high levels of radiation, eventually eliminating and even reversing the higher potential reproductive output associated with early reproduction and large clutch size. These findings are consistent with the hypothesis that radioactive contamination reduced levels of dietary antioxidants in yolks, with negative consequences for hatching success and reproductive success.
Møller
Anders Pape
AP
Laboratoire de Parasitologie Evolutive, CNRS UMR 7103, Université Pierre et Marie Curie, Bât. A, 7ème étage, Case 237, 75252 Paris Cedex 05, France. amoller@snv.jussieu.fr
Karadas
Filis
F
Mousseau
Timothy A
TA
D000818:Animals; D000975:Antioxidants / Q000378:metabolism*; D002338:Carotenoids / Q000378:metabolism; D047852:Chernobyl Nuclear Accident; D052284:Clutch Size / Q000528:radiation effects; D004032:Diet; D004307:Dose-Response Relationship, Radiation; D015536:Down-Regulation; D017753:Ecosystem; D004530:Egg Yolk / Q000378:metabolism / Q000528:radiation effects*; D005260:Female; D005298:Fertility / Q000528:radiation effects*; D046109:Passeriformes / Q000378:metabolism*; D014801:Vitamin A / Q000378:metabolism; D014810:Vitamin E / Q000378:metabolism; D015053:Zygote / Q000378:metabolism / Q000528:radiation effects*
D000975:Antioxidants; D014801:Vitamin A; D014810:Vitamin E; D002338:Carotenoids