Scientists studying kea, New Zealand’s alpine parrot, revealed that the famously mischievous birds could understand probabilities, an impressive mental feat.

The pair of researchers put six birds through a series of trials to see how they made decisions when faced with uncertainty. When prompted to choose, the kea generally opted for scenarios where they were more likely to earn a reward. This work is further evidence of some birds’ general intelligence, according to the paper published in Nature Communications.