51-66 cm (20-26") Uncommon and widespread. Boreal forests, eastern deciduous forests.
Largest accipiter, crow-sized. Dark blue-gray above; white eyebrow stripe (broader behind eye) separates dark cap from dark cheek patch; white with dense gray barring below which appears gray at a distance; white undertail coverts.
In flight; longish tail and rounded wings; less "flap and glide" than Sharp-shinned and Cooper's Hawks.
Song: loud "kak-kak-kak-kak".