Oxidative stress and cognition in ecology

Abstract

AbstractOxidative stress occurs when the body's antioxidant system is unable to prevent reactive oxygen species from causing cellular damage, and over the last two decades, oxidative stress has received extensive attention from behavioural ecologists investigating its links with life‐history traits including reproduction, growth, and immunity. Despite the breadth of studies examining oxidative stress in relation to animal behaviour, life‐history, and health, the role of oxidative stress in shaping variation in the cognitive abilities of wild animals has been almost entirely neglected. Here, I discuss how oxidative damage in the brain may affect cognitive performance in the wild, both directly and by mediating links to other life‐history traits. First, I outline evidence that the brain is particularly susceptible to oxidative stress and highlight medical studies demonstrating that oxidative damage impairs cognitive ability in humans and other animals. I then explore how oxidative stress may similarly affect cognition and behaviour in an ecological context, and the far‐reaching consequences this could have on wild animals' lives, including their fitness. Finally, I suggest methodological tools that could clarify the role of oxidative stress in cognitive ecology and approaches that combine existing ecological assays of behaviour and cognitive performance with bio‐medical experimental designs. While challenging to investigate, oxidative stress in the brains of wild animals may have profound consequences for their cognition and health, which currently remain almost entirely unexplored.