Memory retention of conditioned aversion training in New Zealand's alpine parrot, the kea

New Zealand pest control operations commonly deploy toxic sodium fluoroacetate (1080) baits to control introduced mammalian predators and protect vulnerable native fauna, yet the highly intelligent kea (Nestor notabilis) is at risk of mortality following ingestion of toxic baits intended for their protection. We tested the retention of conditioned aversion in 11 captive kea that had learned to avoid baits containing the bird repellent anthraquinone alongside color, olfactory, and taste cues. We revisited kea over increasing time intervals (3 days, 5 weeks, 3 months, 6 months, and 1 yr) offering them otherwise identical non-repellent baits. Kea retained their aversion until the final session, 1 year after previous exposure to reinforcement, and almost 2 years since previous exposure to repellent. Whether the kea forgot their aversion or the repeated exposures to non-repellent baits resulted in extinction of the aversion, our results indicate that kea are capable of remembering an aversion for long enough to be of practical use to conservation managers in reducing kea mortality through 1080 operations.