Behavioral flexibility is related to exploration, but not boldness, persistence or motor diversity

Behavioral flexibility, the ability to change behavior when circumstances change based on learning from previous experience, is thought to play an important role in a species' ability to successfully adapt to new environments and expand its geographic range. However, behavioral flexibility is rarely directly tested at the individual level. This limits our ability to determine how it relates to other traits, such as exploration or persistence, that might also influence individual responses to novel circumstances. Without this information, we lack the power to predict which traits facilitate a species' ability to adapt behavior to new environments. We use great-tailed grackles (a bird species; hereafter “grackles”) as a model to investigate this question because they have rapidly expanded their range into North America over the past 140 years. We evaluated whether grackle behavioral flexibility (measured as color reversal learning) correlated with individual differences in the exploration of new environments and novel objects, boldness towards known and novel threats, as well as persistence and motor diversity in accessing a novel food source. We determined that exploration of a novel environment across two time points and persistence when interacting with several different novel apparatuses were repeatable in individual grackles. There was no relationship between exploration or persistence and the two components of flexibility - the rate of learning to prefer a color option in the reversal learning task, and the rate of deviating from a preferred option. However, grackles that underwent serial reversal training to experimentally increase behavioral flexibility were more exploratory in that they spent more time in close proximity to the novel environment relative to control individuals. This indicates that, the more an individual investigated a novel apparatus, the more it was able to potentially learn and update its knowledge of current reward contingencies to adapt behavior accordingly. Our findings improve our understanding of the traits that are linked with flexibility in a highly adaptable species. We highlight the importance of using multiple different methods for measuring boldness and exploration to evaluate consistency of performance and therefore the methodological validity. We also show a link between exploration and behavioral flexibility that could facilitate adaptation to novel environmental changes.