Day of the Hawks: Cooper's Hawk

In addition to the pair of red-shouldered hawks today, this Cooper's Hawk also was observed. I got a photo of the Cooper in one of the azalea bushes, but also observed him on the ground under the bird feeder as he attempted to grab one of the smaller birds to eat.
As the Cooper's and red-shouldered hawks are about the same size and have some similar color traits (feddish chest, reddish under the wings), here is how I tell the two apart:
>Cooper's back is dark gray while the red-shoulder's back is dark brown with some white specks.
>Both have barred tails - Cooper's is black bar, red-shoulder's is white
>The red-shoulder's neck is much thicker than the Cooper's. When observing them with a bright or blue-sky background this can be very helpful.