Those tiny flecks against the sky are nighthawks, which really aren't hawks at all.
A small flock of nighthawks passed over sillydoggarden on Sunday. On their way to South America, the birds swooped and turned and counter-turned, all the while catching flying insects in their mouths. You can't tell by my miserable photo attempt, but they have white bands on their wings that are visible in flight. A change in season is imminent. Can the hummingbird migration be far behind?
The Star Tribune writes about nighthawks here. And John Latimer describes watching them as they move south.