It is difficult to differentiate between the three species, the only exception being the adult Goshawk. It's barred grey underside and blackish head with distinctive white eyebrow marking, set it apart from the other adult Accipiters. Adult Cooper's and Sharp-shinned Hawks have plumages which are almost exactly alike. Their wings and backs are blue-gray, while their underparts are barred with white and rufous. All immature Accipiters have brown backs and white underparts, which are heavily streaked with brown on both the belly and chest.
Size is the main difference between the species.
Sharp-shinned Hawks are smallest, about the size of a jay. Goshawks are the largest, sometimes reaching the size of a Red Tailed Hawk. Cooper's are right in the middle, crow sized. Female Accipiters are always larger than the males. Accipiters have rounded wings and long tails, which enable them to maneuver quickly and accuratly through trees and brush.