I saw a red-tailed hawk chase off a heron in flight on Saturday over one of the fields on my run. That was one territorial bird.
They are that-especially at this time of year when they have babies still unfledged. The ones here nest in the tall trees, and are always on the hunt in the morning, hovering over the little clearings in the woods.
I once saw a red tailed hawk drop into a dive and grab a dove right out of the air-dove feathers exploded everywhere, and the hawk flew away with dinner. They are so graceful when they are just cruising, though...