Poor Birdie

So we went on a walk last night and came across these birds. The big one we think was a hawk. So the little birds were making a lot of noise, so we sat there and watch for about 5 minutes. These three little birds were picking on that big bird flying into it and swaking at it. They did it over and over. They must of had a nest near by that they were trying to protect because they sure tried hard to get him off that pole. They would all take turns attacking him and trying to get him to move. It was so sad. They would run in to him over and over and he would just sit there and let them run into him. He didn't even make a noise or movement. I had never seen such little birds pick on a bird three times their size.