While conducting a spring migration count along the C&O Canal near the
Fletcher's Boathouse in Washington DC, I observed a pair of Cooper's Hawk in
what seemed to be courtship behavior. One individual was in display mode and
it's behaviour quite accurately matched a description in this species'
section in 'The Birds of North America Online' website (*
bna.birds.cornell.edu*):

"....slow, exaggerated wingbeats, alternated by gliding with wings held in a
dihedral."

Dhananjaya Katju
Washington, DC