Up to this point we've only seen Cooper's in our yard. We usually see the markings to verify them as such. We have seen Sharp-shinned, but we've always been elsewhere with the experienced who point them out to us. At home, we're on our own. :)
I was about to pass this off for a Cooper's but just want to make sure. I didn't see the legs or tail. I have been looking at this link trying to figure this out. http://www.birds.cornell.edu/pfw/AboutBirdsandFeeding/accipi...
I will say I cannot see the eye difference the site brings up with the Sharp-shinned Hawk's appearing more centered between front and back of head.
Is this a sub-adult? This has an eyebrow and a few white feathers. If this is a Cooper's, I am not seeing the darker "cap". I put a picture of the back of the head on here, if it will help with the id. Sorry about the wonky colors. I have no idea what setting my son used. The middle one is the most true to life- he changed something on the camera.