Perhaps you have seen videos of the incredible flocking behavior sometimes shown by starlings. They’re on YouTube. What’s amazing is the cohesiveness of the flowing flight of the flock. Flock edges as it sways and swings are as exact as if drawn with a pen. An excellent example of this recently posted is called Dance of the Dunlins. A large flock of this shorebirds swirls into motion to avoid the attack of a falcon. Find it at http://birdnote.org/video/2013/10/dance-dunlins
Dunlins are shorebirds that migrate through Minnesota, but not in flocks that might display this flying behavior.