I was bowhunting about 15 years ago and had a similar experience. With a Coopers Hawk, I was sitting under a cedar tree on a scrub Oak Range, one afternoon, and after a while birds scattered, squirrels disapeared, and it was real quiet for what seemed like a long time. After a bit, a Junco flew down from a branch in front of me about 4 feet away, in a flash, the coopers hawk swooped in, grabbed the bird on the ground, wings spread out and adjusting his talons in the unfortunate bird’s body, and then flew awy with it.
NOW… it may sound like BS, but I swear it is true. I was sitting in my ground blind about 5 years ago, watching a small Oak Flat in front of me that had a few hemlocks mixed in. About 2:30 in the afternoon a small basket racked six pointer came feeding in, he was relaxed and feeding, I was about to draw waiting for him to take a couple more steps into my shooting lane, and this bloody red tail hawk swoops down and nails this gray squirrel in one of the hemlocks! They both made an awful racket and surprised the crap out of me and the Buck. Needless to say the buck jumped backwards and departed for friendlier territory.
The most profound thing I saw in a different area a few yeaers back, again I was deer hunting in a ground blind and watching this gray squirrel eat an acorn on top of a field stone fence. Here comes a redtail swoops down and carries the little guy away. Five minutes later, another squirrel, another acorn, same spot. Life goes on as if nothing happened.