#1 I like the idea and the composition - offset rather than centered works well here. Given that you have worked to remove the background with the use of a white material, I would suggest that there needs to be far more depth of field. All of the blueberries should be sharp, in my opinion.
#2 Head on compresses a subject and flattens it, removing the sense of depth. In this case I can imagine that it would be difficult to get down at water level to get a shot with more depth, but I think that the point of view works against the subject by flattening it.
3# The subject is very cool - nice find! I love faces in natural materials, whether man-made of naturally occurring. Including the background gives us a good sense of place, but I don't think that this subject needs that. In addition, the line of the tall weeds and the tree line bound the subject and prevent any of the background from contributing anything positive. A tighter crop showing the face would allow the viewer to take in just the subject without any distracting background. In my mind I'm picturing a very close-up shot where the edges of the stump are outside the frame, perhaps from an angle. Just the same I like this one.
#4 It's tough to say on this monitor, but it looks like the focus might have hit the shoulder of the bird rather than the eye. In my experience having the eye in focus is vital, even if the rest of the critter is soft, as long as the eye is sharp it comes across much stronger.
Neat stuff just the same - thanks for sharing these...
- Randy