I read that earlier on FB....really interesting. Especially the part about how they lay twigs and things on a dead crow, like a burial. I've also watched them form an attack on a hawk in my front yard....it was brutal, until I rushed out there.
With a broom? LOL! Seriously, I saw a group of crows form an attack on a dead owl in a tree years ago. They were going nuts. Some neighbors got the owl down, it was dead and it was banded but it was an owl and they must have regarded it as a threat because it was a mob scene. We called the proper wildlife agency, they picked it up as it was banded. So - they ain't dumb. I wonder if they could be trained to drop off pharmaceutical samples?
What other bird exchanges trinkets! The is a lot of crow lore out there too. http://www.perspectivesmagazine.sk/news/ravens-and-crows-in-mythology-folklore-and-religion/
No broom, I just opened the front door and went out there...they all scattered. As for training them, I'm sure they could be trained.
Crows are amazing birds. It might be cool if someone could rig up a "crow cam" similar to the "eagle cams" and watch them on the nest and raising their young.