Saturday 10/23 there was an Imm. Red-Tail Hawk hanging around the Dept. of the Interior Building and DAR Constitution Hall area.  One American Crow was taking swipes at it diving down at it and then swooping up at the hawk perched on a fire escape.  The crow reminded me of Hummingbird displays.
 
I wasn't out to go birdwatching, but this sighting brightened my morning.  At least the hawk kept the local Ring-Billed Gulls, Starlings and Rock Pigeons on the move.
 
Denise Ryan
Washington, DC