Every year around this time, when I lived in the country, hundreds of crows would arrive (together) and alight in the trees in the woods behind my house. They made so much noise cawing a person couldn't hear themselves think. I'd take out the binoculars and get the dog and we'd watch them until they finally took off. I figured they were migrating because I didn't see them in winter. It was exciting for me, and the dog would stay quiet while watched the crows.
Sometimes in the summer the hawks try to get them. They do not succeed, at least while I've been watching. The lone crow is instantly rescued by the other crows (25 to 50 of them, I estimate). They all suddenly just swoosh out of the big tree across the road. The other crows chase off the hawk. It is quite exciting to see. Those hawks used to try to get my dog. I'd walk him, and flap my arms so they would think I was a bigger bird. When he was larger (too big for them), they'd sometimes fly right over him. I had to stand guard because I didn't want the dog to catch the hawk. That would have ended badly - probably with an injured dog. Aidan is really good at leaping into the air and catching birds. He's done it three times in 10.75 years. Luckily they die instantly. I didn't know birds would fly that low over a dog. I guess they don't know that terriers have high prey drives.