Not so birdbrained Auscape/Universal Images Group/Getty

New Caledonian crows have figured out how to move two things in one fell swoop. The adept tool users have been filmed inserting sticks into objects to transport both items at once – a feat that has never been seen in non-humans.

Ivo Jacobs of Lund University in Sweden and his team recorded the unique behaviour in a group of captive crows (Corvus moneduloides). They saw how one crafty individual slipped a wooden stick into a metal nut and flew off, carrying away both the tool and the object.

A few days later, another crow inserted a thin stick into a hole in a large wooden ball to move the items out of the room.


The team observed four other instances of the crows’ clever trick. One of these involved using a stick to transport an object that was too large to be handled by beak.

The birds’ novel mode of tool use may be a reflection of their intelligence and exceptionally large brains. Although we already knew crows could use tools, adapting this behaviour to other contexts involving novel objects and purposes shows behavioural flexibility, says Jacobs. “This is typically seen as a hallmark of complex cognitive abilities.”

Crafty crows

More research is needed to see whether the birds also use tools this way in the wild. One possible use could be transporting unwieldy food items that they then cache for later, the team speculates.

“It is really interesting,” says Corina Logan of the University of Cambridge. “It does seem to be a new form of how they use tools. I am really curious to see if they do this in the wild.”

But at this point it is difficult to say whether this is a big advance for animals, says Jolyon Troscianko of the University of Exeter. It is hard to draw firm conclusions from just two crows, he says.

Journal reference: Animal Cognition, DOI: 10.1007/s10071-016-1016-z

Read more: Crow cameras give a bird’s eye view of tool-making in the wild