Plants and Animals

Crow Brains Reveal Secrets of Their Intelligence

December 4, 2013 | by Lisa Winter

Photo credit: Felix Moll, Institute for Neurobiology, University of Tübingen

Crows are well known for their intelligence. In fact, the entire Corvidae family is renowned for being the smartest of all birds and some of the smartest of all animals. The secret to their superior intellect has been located in their brain for the first time, according to a new study from Lena Veit and Andreas Nieder from the Institute of Neurobiology at the University of Tübingen. The paper was published in Nature Communications.

Corvids like crows and ravens have been known for their intelligence long before much research was given to the subject. In addition to being one of the few animals capable of using tools to find food and solve problems, they have complex social structures. Information is shared within the murder so that group decisions can be made. They have incredible memories which allow them to recognize human faces. This is bad news for the people that aren’t well liked by the birds, because word can spread and the crows will dive and attack faces.

Unfortunately, because bird brains are so different from mammalian brains, not a lot has been known about how decisions are made and where avian intelligence actually comes from. For the study, the crows were trained to perform a series computerized memory tests. An image would flash on the screen and then disappear. Next, two more images would appear. One was the same as the first while the other was different. Some portions of the test required the crows to find a match with the first image and other sections wanted the image that was different. After a brief training period the crows were able to do the test effortlessly, even when unfamiliar images were used.

While the crows were busy selecting images, researchers were mapping the birds’ neurological function. They discovered that there was a great deal of activity in the nidopallium caudolaterale, which is somewhat analogous to the human prefrontal cortex. This is the region of the brain where higher-thinking occurs and executive decisions are made. The researchers also noticed activity in different areas based on if the crow was supposed to pick the item that was the same while a different area was used when the selected image was supposed to be different. After a while, the researchers could use the bird’s brain activity and see what it was going to select before the bird had a chance to submit its choice.

Because bird brains are so different from mammalian brains, there aren’t a lot of shared structures from before the divergence over 300 million years ago. Even though the structure isn’t the same, there are a lot of similarities in the decision-making cells. The researchers speculate that the intelligence seen in mammals (primates, specifically) and that found in birds could very well be a product of convergent evolution.