I was looking out the window this morning at my birdfeeders. There were about a half dozen birds and a few squirrels enjoying their breakfast. And then all of a sudden almost everyone scattered, except the squirrel in the sunflower tray. And then he took off like “his head was on fire and his was catching.” And I saw the hawk swoop by and it all made sense.
Years ago I was in the back lot of the shop and heard a bunch of crows making a heck of a racket. Probably 30 or more flying overhead. Then I saw an owl in the trees, just sitting there minding its own business. The racket continued for about 20 minutes until the owl flew away.
They must have had a good lookout that can talk bird and squirrel.
I once saw a hawk snatch a bird in mid fly, it was like someone shot the bird as feathers were flying everywhere. Nature never stops to amaze me.
Another dive bombing at the Bird Feeder Buffet. The squirrel got away.
Great squirrel evasion tactics. 
Squirrels act like it’s their first day on the job