Disentangling the environment in wildlife microbiom-behaviour interactions: Response to Davidson et al

There is growing evidence that the gut microbiome strongly influences animal physiology and behaviour. In their recent article in TREE, Davidson et al. call for research into the relationship between the gut microbiome and behaviour in free-living wildlife to better understand the mechanisms and evolution of behavioural plasticity. They provide a framework for investigating microbiome-mediated behaviour, including microbiome manipulation to infer causality. While the authors recognise that the environment influences both gut microbiomes and behaviours, we suggest that their proposed framework does not adequately capture the complexity and multiplicity of environment–microbiome–behaviour links. As we argue, any examination of the links between the gut microbiome and behaviour in free-living wildlife demands a more holistic perspective of the role of the environment in shaping gut microbiomes, behaviours, and their interactions.