What Makes this Photo?

Anhinga Trail, Everglades National Park

What is it that makes this image?  Is the fact that the eye is tack sharp or that the background is blurred giving the subject separation?  Is it the vibrant colors in the eye and the beak?  Is it the use of the "rule of thirds" in the composition?  I would honestly say that they all contribute to the image but there is really one thing that makes it work.  At least for me.  It is the blood on the beak.  It is the implied struggle for life.

What do you think?