Day 70: Birds might know we’re watching them

Jackdaws, with eyes more like people than other birds, seem to be able to follow the human gaze and learn from it. Credit: John Haslam from Dornoch, Scotland

“Bird brain” might not be the worst insult you can hurl at someone.

It turns out birds notice and can respond to the human gaze. Hand-raised jackdaws (relatives of crows, ravens and jays) were found in a study to avoid food if an unfamiliar person was looking at it, thought to be a response to competition. But if an experimenter encouraged the birds toward food reward by looking at it intermittently, the birds took the clue.

And by that measure, the birds seem smarter than dogs and even chimps, which can pick up on other body language cues, like head orientation, but not as much on where people are actually looking.

It’s well known that people communicate their intentions and disposition using their eyes, but scientists have been puzzled about the communicative function of eyes in other animals. Many species show aversive reactions to eyes, and several animals follow the gazes of members of their own species in order to get information. But most animals are oblivious to such subtle signs of attention, and hardly any animals use them in a cooperative context.

Nathan Emery, of the University of Cambridge and Queen Mary University of London, led the new study. He and his co-authors experimented with hand-raised jackdaws, pair-bonded social birds that boast eyes more like people than other birds, with a dark pupil surrounded by a silvery white iris. In some trials, people either familiar or strange to the birds looked at a food rewards as the birds were given the opportunity to pursue them. In others, the study leaders tried to encourage the birds toward the food with directed looks at it, and other signals.

Hand-raised jackdaws took significantly longer to retrieve a food reward when a person was looking at it, rather than looking away. The birds hesitated only when the person in question was unfamiliar and thus potentially threatening.

In addition, the birds were able to interpret human communicative gestures, such as gaze alternation and pointing, to help them find hidden food. 

The researchers suggest the results could mean the birds have a natural tendency to attend to the eyes of their fellows — or, their abilities benefited from intense human contact during socialization. 

“Jackdaws seem to recognize the eye’s role in visual perception, or at the very least they are extremely sensitive to the way that human eyes are oriented,” said Auguste von Bayern, a co-author and a behavioral ecologist at the University of Oxford. The results appeared online this week in Current Biology, a Cell Press publication.

The researchers suspect that jackdaws are sensitive to human eyes because, as in humans, eyes are an important means of communication for them.

“We may have underestimated the psychological realms of birds,” von Bayern said. “Jackdaws, amongst many other birds, form pair bonds for life and need to closely coordinate and collaborate with their partner, which requires an efficient way of communicating and sensitivity to their partner’s perspective.”

Sources: a Eurekalert press release and the study.