This having been tested by having humans wear different masks when catching birds in different places:
The birds quickly learned that the masked bird-trapper was bad news and proceeded to scold the mask-wearer anytime they saw him or her. But over the years, the researchers found, the mobbing became more and more widespread. In February, Marzluff said, he ventured out of his office in a mask he’d worn five years earlier while trapping seven birds.
“I got about 50 meters [165 feet] out of my office and I had about 50 birds on me, scolding me,” he said. “I hadn’t worn that mask on campus for a year.”
The study itself is old news, but the final line of this particular account caught my attention:
The researchers … are now using brain-scanning techniques on captured birds to find out what’s happening in the crows’ brains when they see a dangerous face.
Crow pov summary: Crows know crow-catching humans are bad news. They warn them to back off. But the humans keep it up. So the crows get all our friends to warn said humans off, too. And they keep it up for a full five years, just to be safe.
So how do the humans respond? They amp the bird catching up and throw in some bonus brain scans.
Your move, crows.
One … doesn’t imagine this ending well for the two-leggers. (Except for the part where, apparently, it did.)