The oxidative cost of reproduction depends on early development oxidative stress and sex in a bird species

Abstract

In the early 2000s, a new component of the cost of reproduction was proposed: oxidative stress. Since then the oxidative cost of reproduction hypothesis has, however, received mixed support. Different arguments have been provided to explain this. Among them, the lack of a life-history perspective on most experimental tests was suggested. We manipulated the levels of a key intracellular antioxidant (glutathione) in captive zebra finches (Taeniopygia guttata) during a short period of early life and subsequently tested the oxidative cost of reproduction. Birds were allowed to mate freely in an outdoor aviary for several months. We repeatedly enlarged or reduced their broods to increase or reduce, respectively, breeding effort. Birds whose glutathione levels were reduced during growth showed higher erythrocyte resistance to free radical-induced haemolysis when forced to rear enlarged broods. This supports the hypothesis predicting the occurrence of developing programmes matching early and adult environmental conditions to improve fitness. Moreover, adult males rearing enlarged broods endured higher plasma levels of lipid oxidative damage than control males, whereas adult females showed the opposite trend. As most previous studies reporting non-significant or opposite results used females only, we also discuss some sex-related particularities that may contribute to explain unexpected results.

The role of the antioxidant system during intense endurance exercise: lessons from migrating birds

“…Alternatively, do birds consume antioxidants on their wintering grounds prior to migration and store them for use during spring migration, thus creating carryover effects? Because the breeding season is another life stage that may cause an increase in RS (Romero-Haro et al, 2016), it is also possible that birds in spring migration utilize their antioxidant system differently to reduce the costs of migration while preparing for breeding. These questions could be addressed via field experiments that longitudinally measure antioxidant capacity (both enzymatic and non-enzymatic) and oxidative damage in migratory birds across the year [i.e.…”

The Influence of Urban Environments on Oxidative Stress Balance: A Case Study on the House Sparrow in the Iberian Peninsula

“…Reproduction could increase oxidative stress as an inevitable consequence of increased reproductive effort (Romero-Haro et al, 2016) and/or because the developing offspring consume antioxidants otherwise allocated to selfmaintenance (Alonso-Alvarez et al, 2004;Moller et al, 2010;Berglund et al, 2014). Therefore, oxidative stress may have a dramatic effect on bird fitness during the breeding season.…”

Reproductive effort and oxidative stress: effects of offspring sex and number on the physiological state of a long‐lived bird

“…; Ołdakowski et al . ; Romero‐Haro, Sorci & Alonso‐Alvarez ), but with contradictory outcomes. Moreover, in a recent meta‐analysis, Blount et al .…”

“…; Costantini et al . ; Romero‐Haro, Sorci & Alonso‐Alvarez ). Offspring sex has also been shown to induce fitness and/or physiological costs (e.g.…”