I like that you also included the birds' heads with their feathers still intact. This way the viewers look longer at the picture because they're comparing the skulls to the heads and notice more details. Additionally the picture is in grey tones, so the colourful feathers don't get in the way of the study. After all its about the skulls and not the bird heads.
The only thing I'm wondering about is why the bald eagle's beaks point in two different directions, while all the other birds beaks point to the right. This makes the eagle stand out, without there being a reason why the "real life head" shouldn't also have been pointing to the right.
But all in all, great work