Of the many stories about the uncanny ability of American crows to recognize human faces, my favorite is the one about the school bus driver in Bellevue, Wash., who fed seeds and peanuts to crows near her home and was briefly suspended from her job because the flock started following her to work.

Now, a new study explores wild crows’ talent for recognizing people. In general, it confirms long-standing farm tales and folklore about the ubiquitous birds. In particular, it shows that a crow definitely can tell the difference between former Vice President Dick Cheney and a caveman. 

In 2006, John Marzluff, an ecologist at the University of Washington, Seattle, was using nets to capture local crows as part of research on how expanding crow populations were affecting other birds, Science magazine reported.

His research team, however, learned that the crows weren't easily fooled twice. "We'd go back to recapture birds, and it seemed obvious that they had learned to recognize and fear us," he said.

So Marzluff launched experiments designed to test how much attention crows paid to human faces.

Here is how Science’s David Malakoff described the study: Working at five different sites in and around Seattle, Marzluff first had researchers record how the birds reacted when people walked by wearing several rubber masks-including one of Cheney and one of another craggy visage they dubbed the "caveman."

Some weeks later, a trapper wearing one selected mask — the caveman, for instance — moved in with a net launcher and captured and marked seven to 15 crows. Then, for nearly three more years, masked researchers periodically revisited the sites — often mixing with large crowds of other pedestrians — and again recorded how the crows reacted.

The results — reported recently in the journal Animal Behaviour — led the researchers to conclude that crows don't forget the face of the person who trapped them.

Prior to trapping, less than 5 percent of the crows scolded the person wearing the caveman mask. After a trapper wore that mask in some experiments, however, as many as two-thirds of the birds would become upset when they saw the mask and start scolding, mobbing and dive-bombing the wearer. It didn't matter who wore the mask; the birds appeared to ignore differences in age, height, gender, ethnicity and walking gait-they just focused on the faces.

In contrast, the birds essentially ignored researchers wearing "neutral" masks not associated with trapping-such as Dick Cheney's rubber double.

Moreover, the “dangerous” mask drew more reaction over time, suggesting that some crows learned from others to dread it. And they didn’t forget. Marzluff's students recently donned the masks to see if the crows still remembered their trappers.

"It's remarkable,” Marzluff told Science. “It's been 4 years now, but they see that mask and still go crazy."