When I lived on my farm, crows would raid the hen house and pinch eggs.
So I built a wire mesh tunnel that had a right angle in it, and when the crows landed to go into the hen house they could only see the mest and not the angle that would/could give them entry. The hens had no problem with it, but the crows? Not so smart after all.
I used to fire the odd shot gun shell in to the air to scare them away and they learned to discern between a shot gun, a broom handle or even a length of pipe.
If I walked out of my work shop with a shottie - they were out of there.
If I walked out with a length of pipe or similar, they just sat in the trees and looked at me. Maybe there is some degree of higher ornithological intelligence there.