A VERY timely article for me. About a month ago here in Silicon Valley, I noticed that a crow had been violently torn apart and the pieces scattered all over my backyard lawn. I assume the killer was a raccoon--another improbably intelligent animal. How those fat, little ninjas do what they do is beyond me, but one had apparently caught a crow. A few hours after I noticed the carnage, I grabbed a paper grocery bag and some rubber gloves and went outside to collect the crow parts.
As soon as I touched the first piece (a large, black, detached wing), a dozen crows appeared out of nowhere flying in tight circles over my head (about the height of the roof of my 2-story house) and shrieking. They must have been standing watch for hours waiting to see what would happen. Within a minute or so, their numbers had doubled, swarming like bees and screeching. They went so berserk that I thought for sure they would swoop down and peck at me like Alfred Hitchcock's "The Birds", but they didn't. They stayed up there and screeched the whole time I was cleaning up (maybe ten minutes).
I took the bag over to the recycling bin on the side of the house. Property is expensive, so the houses are close together leaving only a narrow slit of sky above me. The crows followed me and flew back and forth right above the gap, still screeching at me. I hadn't killed the bird, but they were acting like an angry mob blaming the wrong guy.
I was already aware of the studies showing that crows recognize individual people and can bear grudges for years. I was afraid that's what I was going to end up with, but after that event, they never bothered me again, and I see crows around my house frequently. Maybe they DID know that I wasn't the killer, but they had some other agenda. From my perspective, they (and raccoons) are essentially alien intelligences living among us that I always underestimate and still don't understand.