What do you think of this fact?
Ever messed with a crow? Better hope it didn’t get a good look at your face. Crows recognize individual people and remember for years who gave them trouble.
The mask experiment
A team led by researcher John Marzluff at the University of Washington in Seattle showed this. Starting in 2006, the researchers netted American crows on campus and at other sites around Seattle, banded them and let them go. While doing it, they wore rubber masks of human faces.
The “dangerous” mask was a caveman mask. As a control, they used a second, neutral mask that was never worn while catching birds. The result was clear: whoever walked around campus in the caveman mask got loudly scolded by crows, no matter who was underneath. The control mask barely got a reaction.
When the researchers wore the caveman mask upside down, some crows even turned their heads upside down to get a proper look at the face.
A grudge that spreads
Nearly 7 years after the study began, the birds were still harassing the mask, even though they only saw it twice a year for a few hours. Even more surprising: the share of crows joining in on the scolding had roughly doubled. Most of them had never been caught and likely never saw the original event. They apparently learned it from other crows, both from their parents and from their peers.
In a follow-up study, the team looked at the brains of 12 wild crows. Seeing the threatening mask lit up a region that works much like the amygdala in mammals.
According to Marzluff, it all makes sense. In the same neighborhood, one person might feed the birds while another wants them gone. Knowing friend from foe is a real advantage.
So crows basically keep a blacklist, and they share it with family and neighbors. Being nice to them pays off.