They are highly intelligent, and seem to pass on the wisdom from elders to the youngsters.
Years ago we bought a small farm that had laid fallow for a number of years and had 'accumulated' a large crow population. They thwarted our
efforts at farming by methodically walking the corn rows, pulling up the newly sprouted plants and stripping the remaining part of the kernels.
(Among other stunts)
After much frustration, my husband was given some advice by an old-timer at the feed store. He said to kill one crow and hang it on a post or tree
limb where the other crows could see it. The other crows would recognize it as a warning and leave our field alone.
Even though it 'violated' our 'live and let live' policy, we shot one and hung it on a tall pole. After a considerable 'caw-fest' in the
surrounding trees, they left. Not only did they stay out of the garden, they would fly AROUND our entire pasture area!
It has been almost 25 years and they have just gotten to the point where one will occasionally land in the garden or yard. They usually land in the
pasture, walk up to the gate and look suspiciously toward the house. So it would seem that the warning was passed on to the younger generation.