title: Nestling rearing is antioxidant demanding in female barn swallows (Hirundo rustica).
abstract: Reproduction is a demanding activity, since organisms must produce and, in some cases, protect and provision their progeny. Hence, a central tenet of life-history theory predicts that parents have to trade parental care against body maintenance. One physiological cost thought to be particularly important as a modulator of such trade-offs is oxidative stress. However, evidence in favour of the hypothesis of an oxidative cost of reproduction is contradictory. In this study, we manipulated the brood size of wild barn swallows Hirundo rustica soon after hatching of their nestlings to test whether an increase in nestling rearing effort translates into an increased oxidative damage and a decreased antioxidant protection at the end of the nestling rearing period. We found that, while plasma oxidative damage was unaffected by brood size enlargement, females rearing enlarged broods showed a decrease in plasma non-enzymatic antioxidants during the nestling rearing period. This was not the case among females rearing reduced broods and among males assigned to either treatment. Moreover, individuals with higher plasma oxidative damage soon after the brood size manipulation had lower plasma non-enzymatic antioxidants at the end of the nestling rearing period, suggesting that non-enzymatic antioxidants were depleted to buffer the negative effects of high oxidative damage. Our findings point to antioxidant depletion as a potential mechanism mediating the cost of reproduction among female birds.
authors.affiliation: Department of Biology, University of Antwerp, Universiteitsplein 1, 2610, Wilrijk, Belgium, davidcostantini@libero.it.
authors.forename: David
authors.initials: D
authors.lastname: Costantini
authors.forename: Andrea
authors.initials: A
authors.lastname: Bonisoli-Alquati
authors.forename: Diego
authors.initials: D
authors.lastname: Rubolini
authors.forename: Manuela
authors.initials: M
authors.lastname: Caprioli
authors.forename: Roberto
authors.initials: R
authors.lastname: Ambrosini
authors.forename: Maria
authors.initials: M
authors.lastname: Romano
authors.forename: Nicola
authors.initials: N
authors.lastname: Saino
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000032:analysis / Q000378:metabolism*; D052284:Clutch Size / Q000502:physiology; D005260:Female; D016014:Linear Models; D008297:Male; D009425:Nesting Behavior / Q000502:physiology; D018384:Oxidative Stress / Q000502:physiology; D012098:Reproduction / Q000502:physiology*; D046388:Swallows / Q000097:blood / Q000378:metabolism / Q000502:physiology*; D013997:Time Factors
chemical_list: D000975:Antioxidants