They're as smart as 5-year olds, have long lives and long memories. They've also been found to pass down obscure information through generations.
In the early 70's, a University of Washington study on Corvids involved students with rubber Richard Nixon climbing up into nests on campus, catching fledgeling crows, taking samples and banding them before putting them back in the nests.
After that, whenever someone wore a Nixon mask anywhere near the University, not only the campus corvids, but any within a 10 mile radius would attack the wearer of such a mask
Twenty years later - as in 5 to 10 generations later, someone decided to somewhat return to the study, and put on a Nixon mask.
Within minutes of stepping out of a building, he was attacked by crows, some of whom were rushing over from other parts of the campus as soon as the hue and cry by the birds was raised.
Mom was working on campus at the time, she saw part of what was going on. The crows surrounded the Zoology department building for months, waiting for "Nixon" to come back out.

Haele