They can also think abstractly enough to mimic paranoia, pretending to hide their food in one place, employing subterfuge to fool rivals, and cunningly moving their feast to another spot. It doesn’t always work, but other tests have shown that they behave differently if they think they are being watched.

In one case, ravens raised in captivity were placed in a room with a covered window with a small peephole flap that could be left open or closed. At first, the window was left uncovered so the birds had full view of anything happening outside the room. Once the window was blocked, the birds were trained that they could see and be seen through the peephole. When the hole was open, the birds took extra care in storing their food. If closed, they behaved normally, even if other birds could be heard in the distance. In light of such studies, researchers concluded the animals were aware of when they could be spied upon and acted accordingly.

Another point of interest is their capacity to think analogously. They have exhibited an aptitude for identifying like and unlike objects from one another. Testing with items of different shapes and colors suggested complex thinking once reserved only for warm-blooded creatures.

They manage these abstractions without the virtue of a mammalian neocortex, the layers of the cerebral cortex that are responsible for higher brain functions like emotions, language, cognition and computation, among others. They appear to have excellent memories too, and can recognize faces of both friend and foe.

How does the walnut-sized bird brain of a corvid mimic such human behaviors? It’s in the neurons, early studies suggest, busily transmitting messages to the nucleus NCL (nidopallium caudolaterale), an area that seems to mimic the neocortex.

Neuroscience has just begun to delve into the mysteries of the corvid brain, so there is likely much more to be discovered. It just goes to show, we aren’t really sure what a crow knows.

SCIENCE & NATURE