Natural habitats are disappearing at record speeds, and our world is becoming increasingly urbanised. Recently, researchers started exploring how cognitive abilities (the mechanisms by which animals acquire, process, store and act on information from the environment) may allow animals to adapt to urban environments. Many of these studies revealed cognitive differences between urban and non-urban dwelling animals and linked these to informational challenges related to the highly dynamic nature of urban environments. Here we hypothesized that urban diets also contribute to such cognitive differences. Although lab-based studies indeed showed important effects of diet on the development of cognition, this idea so far received little attention in the urban cognition literature. We addressed this important knowledge gap by combining theoretical frameworks and methodology from psychology, ecology, and microbial sciences. Specifically, we tested how high-fat high-sugar diets (as found in urban environments) shape cognition. Lab-based studies also showed that diet induced changes in the gut microbiota impacts cognition. Hence, we also tested how such high-fat high-sugar diets affect gut microbiota, and whether gut microbiota composition mediates the effect of diet on cognition. To do so, we used feral pigeons, a species that thrives in urban environments, and whose diet varies widely between urban and non-urban environments, as my model species. We collaborated with a pigeon breeder and racer to examine the relationship between diet, the gut microbiota and different aspects of pigeon’s learning to fly and navigate their environment.
