Comparing cognitive flexibility between queen and worker bumblebees

Being good at learning can come at the cost of other cognitive traits. One such cognitive trait is flexibility - overriding old information with new information - which can trade-off with learning in some species. Bumblebees (Bombus spp.) are useful models to study trade-offs in cognition since closely related individuals have distinct behavioral phenotypes with known differences in cognitive abilities. Foraging queens are better at learning than foraging workers (‘foragers’), but it is unclear if this comes at the expense of cognitive flexibility. In this study, we compared queen and worker bumblebees of two species (B. vancouverensis and B. flavifrons) on their learning and reversal learning performance using a visual learning assay. While B. vancouverensis queens were better at reversal learning than workers overall, indicating no trade-off in learning and flexibility between the two groups, B. flavifrons queens were better at reversal learning than workers for one of the two rewarding stimuli. These findings suggest that species-specific differences may influence the relationship between learning and cognitive flexibility, highlighting that the presence or absence of trade-offs in cognition can vary across bumblebee species. A potential mechanism to explain this variation among species is the bidirectional pathway between the brain and the gut since it is involved in altering the expression of biogenic amines that affect learning and perception, but remains comparatively understudied. To explore this link, we will analyze the gut microbiome composition of wild bumblebees and its association with cognitive performance.