I fed crows for 4 years before I moved to another area. It started with just a family. I noticed the one I called the watcher who would let everyone know when I put out peanuts . The watcher also stood guard while they ate. This family would take turns eating the peanuts. I also noticed grooming of each other. They would sit on the telephone wires and groom themselves or a pair would groom each other. During the fall and winter when crows aren't as territorial and join together in larger social groups I would go out in the morning to as many as 40 crows waiting for food. It always amazed me that they were so territorial when bringing up their families and yet so social at other times.
I'm confident in being able to distinguish between crows and ravens. I've only seen a raven in captivity but the size difference was amazing. I have actually heard a crow that sounded a lot like a raven. His voice was totally different from all the other crows in my area (SF Bay Area).