Oxidative status and social dominance in a wild cooperative breeder

1. Oxidative stress has been proposed as a key mediator of life-history trade-offs, yet the social factors that affect patterns of oxidative states amongst individuals in animal societies remain virtually unexplored. 2. This is important, as rank-related differences in reproductive effort in many social species have the potential to generate, or indeed arise from, differences in oxidative state across dominance classes. 3. Here, we examine rank-related variation in oxidative states before and after a lengthy breeding season in a wild cooperatively breeding bird with high reproductive skew in the semi-arid zone of Southern Africa; the white-browed sparrow weaver (Plocepasser mahali). 4. Our findings reveal that prior to breeding, neither sex showed rank-related differences in markers of oxidative damage or antioxidant protection, suggesting that dominants’ reproductive monopolies do not arise from superior pre-breeding oxidative states. 5. After breeding, however, females (who provision ...