Long-term memory for a learned behaviour in a wild bird

Long-term memory is a crucial adaptation for long-lived species. However, there have been few tests of the long-term retention of learned behaviours in free living, wild animals. Here, we demonstrate that the North Island robin (Petroica longipes; hereafter toutouwai) can recall a learned foraging behaviour for close to 2 years, with no intervening reinforcement. Birds that had been trained to peck open lids to retrieve a concealed food reward spontaneously solved a lid opening task between 10 and 22 months since they had last encountered the lid opening apparatus. By contrast, naive individuals could not solve the task. This long-term retention of a learned skill with no reinforcement, spanning over a quarter of the median age for wild toutouwai in our population, suggests that this threatened species may be an ideal candidate for conservation management strategies aimed at teaching individuals about novel threats and resources.