Because of its length, this is a Cooper’s Hawk, juvenile, and not a Sharp-Shinned. The Cooper’s is said to average sixteen inches in length and the Sharp-Shinned eleven.The Sharp-Shinned and Cooper’s Hawks look too much alike. Side by side the difference is easy. The Cooper’s is much larger. If you have a small hawk pestering the birds at your feeder in the Winter, and it has a long, banded tail, it is probably a Sharp-Shinned. The red eye means maturity. Below is a Sharp-Shinned. The younger ones lack the color.
This one is a Cooper’s. A large bird, it has taken down a pigeon, a bird probably too large for a Sharp-Shinned. This picture was taken behind Walmart in Sterling.
I think this is a not-quite mature Sharp-Shinned.