Looks like a Red Tail. I have seen Crows mob Owls but never knew Hummers got into the act.I know two spots near me where red tails routinely set beside the road and wait for something to get run over.I also have a Blue Jay in the yard that comes every year and he mocks Red Tails.One day I thought man that Blue Jay is really getting good,I looked up and it was a red tail.he has been making appearances ever since.