Dieter Lukas , Kelsey McCune, Aaron Blaisdell, Zoe Johnson-Ulrich, Maggie MacPherson, Benjamin M Seitz, August Sevchik, Corina J Logan 

Behavioral flexibility, adapting behavior to changing situations, is hypothesized to be related to adapting to new environments and geographic range expansions. However, flexibility is rarely directly tested in a way that allows insight into how flexibility works. Research on great-tailed grackles, a bird species that has rapidly expanded their range into North America over the past 140 years, shows that grackle flexibility is manipulatable using colored tube reversal learning and that flexibility is generalizable across contexts multi-access box). Here, we use these grackle results to conduct a set of posthoc analyses using a model that breaks down performance on the reversal learning task into different components. We show that the rate of learning to be attracted to an option (phi) is a stronger predictor of reversal performance than the rate of deviating from learned attractions that were rewarded (lambda). This result was supported in simulations and in the data from the grackles: learning rates in the manipulated grackles doubled by the end of the manipulation compared to control grackles, while the rate of deviation slightly decreased. Grackles with intermediate rates of deviation in their last reversal, independently of whether they had gone through the serial reversal manipulation, solved fewer loci on the plastic and wooden multi-access boxes, and those with intermediate learning rates in their last reversal were faster to attempt a new locus on both multi-access boxes. These findings provide additional insights into how grackles changed their behavior when conditions changed. Their ability to rapidly change their learned associations validates that the manipulation had an effect on the cognitive ability we think of as flexibility.