Great tits show serial reversal learning in the perseverance phase but not in the new learning phase

An animal possessing reversal learning ability is capable of unlearning a previously learned association between a stimulus and a reward and learning a new contingency. It is a form of behavioural flexibility which can be advantageous in changing environments. Serial reversal learning occurs when an animal’s performance improves over repeated reversals of contingencies. In this study, we tested the serial reversal learning ability of great tits (Parus major) in an aviary experiment where they could choose between two laterally positioned locations marked with different symbols. One of the two locations contained hidden food reward, and the side that was rewarding and unrewarding was reversed several times for each bird. We divided the learning process after each reversal into two phases, the perseverance phase and the new learning phase, quantified by the number of visits before and after the first visit to the newly rewarding location respectively. We found that the length of the perseverance phase significantly decreased over repeated reversals. However, there was no corresponding decrease in the length of the new learning phase. This suggests that perseverance and new learning are separate cognitive processes, and that the former may be less challenging than the latter. Initially the birds also showed a colour preference for yellow over blue, but this did not affect their reversal learning ability. The high behavioural flexibility of great tits may help explain their success in exploiting challenging environments.