Six of the eight crows in the study successfully fashioned tools from the paper cards, although the material lacked qualities that leaves have—like veins—making the task more difficult. The two who were unsuccessful were juveniles, indicating their cognitive capacity wasn’t fully developed.

One particularly clever crow, named Emma, was super skilled. Emma made modifications to the card tools so they more closely resembled the tools she first saw and were more uniform all around.

“Our results provide the first evidence to suggest that New Caledonian crows have the cognitive capacity to manufacture objects from a mental template,” the study states. Based on their findings, the researchers now believe crow culture evolves with memory. “Mental template matching is now the leading hypothesis to explain why New Caledonian crow tools show some of the hallmarks of cumulative cultural evolution,” they conclude.

📬 Sign up for the Daily Brief

Our free, fast, and fun briefing on the global economy, delivered every weekday morning.