Gut microbial taxa are associated with problem‐solving success in house sparrows

Behavioral innovations are important traits that allow individuals to adapt to novel situations and changing environments. These behaviors require cognitive skills and behavioral flexibility but the mechanisms behind them are still poorly understood. The gut microbiome is the collection of microorganisms that reside in the gut, and it can influence the brain of the host organism through the gut–brain axis. We hypothesized that the richness and composition of the gut microbiome would relate to birds' abilities to solve novel problem‐solving tasks. For this study, we used wild‐caught house sparrows Passer domesticus , a species that is invasive in many parts of the world in part due to its flexible behavior and preference for urban habitats. We presented individuals with two food extraction tasks and measured their ability to solve them. We also measured the richness and composition of the birds' microbiomes from fecal samples. While microbial diversity did not significantly differ between solvers and non‐solvers, some microbial genera did differ between solvers and non‐solvers. We also found that persistence in solving the task was correlated with problem‐solving success. These results add to our understanding of the avian gut–brain axis; however, further research will be needed to understand how specific microbes impact the brain and behavior of birds.