This is really cute, and I know how hard those guys are to catch on camera.
Compositionally, I think it might work better if you hadn't put the subject smack in the center of the shot. I think the tree is nicer then the bg so I'd probably crop off some on the left and some off the bottom. Getting rid of some of the extra space all around will help the viewer see the subject more easily.
I do like how you used dof to blur the bg and make it less noticeable, but it's just too bright. The squirrel doesn't really stand out well enough against it. Just imagine how well he'd stand out if you could replace all that brown with lush green grass. Not legal for dpc.. but nothing is stopping you now :)
Focus and detail are great though.
You might want to work on the titles b/c some ppl think they're pretty important. Supposedly, they don't help your score, but I do think that bad ones can hurt you. This isn't bad but just boring.
Cute capture. Personaly I would have alomst completely cropped the leaves. They are just too close in colour to the chipmunk, and detract from the great browns of the tree.