Oxidative status and fitness components in the Seychelles warbler

Oxidative damage, caused by reactive oxygen species during aerobic respiration, is thought to be an important mediator of life-history trade-offs. To mitigate oxidative damage, antioxidant defence mechanisms are deployed, often at the cost of resource allocation to other body functions. Both reduced resource allocation to body functions and direct oxidative damage may decrease individual fitness, through reducing survival and/or reproductive output.
The oxidative costs of reproduction have gained much attention recently, but few studies have investigated the long-term consequences of oxidative damage on survival and (future) reproductive output under natural conditions.
Using a wild population of the cooperatively breeding Seychelles warbler (Acrocephalus sechellensis), we tested the prediction that high levels of reactive oxygen species, or high antioxidant investments to avoid oxidative damage, have fitness consequences because they reduce survival and/or reproductive output.
We fo...