What kind of bird is this?

[Raven]

well if those are 4x4 posts that its sitting on
the real measurement is 3.5 inches
and you could stack 3 of those on edge beside it
making it around 10-11 inches tall...
not counting the tail feather length....

as noted by a guy who attached a ruler to his fence
for a more accurate measurement ... he said

when the hawk is standing up straight, the top of its head appears to be at the 1 1/2" mark. That makes this hawk about 9 1/2" tall. Using a photo of a Cooper's Hawk on AllAboutBirds, a Cooper's standing height is about 60% of its length (tip of bill to tip of tail), so the length of this hawk is about 9.5/0.6 = 15.8". Sibley lists the length of a Cooper's as 16" and the length of a Sharp-shinned as 11", so this definitely is a Cooper's Hawk.