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Although oxidative stress is a central topic in biochemical and medical research, the number of reports on its relevance in life-history studies of non-human animals is still low. Information about oxidative stress in wild birds may help describe functional interactions among the components of life-history traits. Currently available evidence suggests that(More)
We evaluated the oxidative cost paid by birds when coping with an immune challenge. We used the phytohaemagglutinin skin test (PHA) to assess the effects of the T-cell-mediated immune response on the concentration of reactive oxygen metabolites (ROMs), total antioxidant barrier (OXY) and total serum carotenoid concentration in wild nestlings of the Eurasian(More)
In recent years ecological research has focused on the relevance of antioxidants and oxidative stress in the evolution of life-history strategies and physiological trade-off in birds. Some studies sought to evaluate whether a consequence of immune response is oxidative stress. In a meta-analysis of 16 studies of ten species of birds including 49 estimates(More)
Carotenoids are considered a limited resource for animals because they are not synthesised by the body. Birds use carotenoids, mainly xanthophylls, for physiological functions, such as anti-oxidant activity, and for colour expression; hence, they need to shunt carotenoids between competitive demands. Recent studies suggest that the anti-oxidant role of(More)
Carotenoid-based skin colorations vary seasonally in many bird species and are thought to be honest sexually selected signals. In order to provide more insight in the potential signal function and underlying mechanisms of such colorations we here quantified patterns of variation of leg coloration in adult male and female Eurasian kestrels (Falco tinnunculus(More)
Oxidative stress has been suggested as a mechanism underlying the costs of reproduction and life history trade-offs. Reproductive activities may lead to high production of pro-oxidants, whose activity can generate oxidative damage when not countered by adequate antioxidant defenses. Because inter-individual differences in the efficiency of the antioxidant(More)
In this review, it is our aim 1) to describe the high diversity in molecular and structural antioxidant defenses against oxidative stress in animals, 2) to extend the traditional concept of antioxidant to other structural and functional factors affecting the "whole" organism, 3) to incorporate, when supportable by evidence, mechanisms into models of(More)
1. Initial work on oxidative stress and antioxidant defences described basic chemical and biochemical properties and processes and applied this information to issues of animal health and husbandry. Seminal experimental investigations on the damaging effects of oxidative stress and the mitigating effects of antioxidant defences were conducted primarily in(More)
Despite extensive research, the potential costs that keep secondary sexual traits honest and evolutionary stable remain somewhat elusive. Many carotenoid-based signals are regulated by testosterone (T), which has been suggested to impose a cost to the signaller by suppression of the immune system or an increase in oxidative stress. Results are, however,(More)
Recent ecological studies have shown that oxidative status could have a significant impact on fitness components in wild animals. Not only can oxidative status reflect the environmental conditions that animals experience, but it can also predict their chances of reproduction and survival in the future in their natural habitat. Such important characteristics(More)