Carol and I were walking down Hamilton Street towards the river this afternoon, and just as we crossed First Street a small drama was enacted in the sky above us.

The first thing I noticed was three or four pigeons wheeling above the State Street bridge, and then flying low and fast upriver. Then a larger bird wheeled above us — it looked like a small hawk.

Twenty or so pigeons came from under the bridge, flying very close to one another, dropping quickly back down to cover by the bridge. The larger bird flapped twice, wheeled into the wind and soared for a second. As it turned above us, I could see it was a small hawk, an accipter, probably a Cooper’s Hawk.

The hawk wheeled twice more, and drifted downwind, towards the south. Suddenly another bird appeared close behind it — a Crow — then two more. The three Crows began mobbing the the hawk, driving it west away from the river. Half a dozen smaller birds broke cover and headed north, away from the hawk. Crows are just about the same size as a Cooper’s Hawk, so it hardly seemed a fair fight — three Crows mobbing the one Hawk.

The last I saw, the Cooper’s Hawk had dropped down to treetop level, still followed by the Crows. My guess is that it wanted to take advantage of its ability to dart and fly swiftly through trees, so it could get away from the Crows. I wondered if it is the mate of the Cooper’s Hawk that is sitting on a nest a few blocks from our house.