These two shots are of the same scene, but one is shot with an 18mm focal length and the other with the 55mm focal length. i think the 18mm works best in this case - in the 55mm, the most interesting feature of the pictures (the squirrel) is in more detail, but in the 18mm, the shot is composed better. The rule if thirds, for example, is obeyed in the 18mm shot - the greenery in the top third of the shot helps to break the monotony of the brown leaves. the lack of this in the 55mm shot makes it a boring and not very well-composed shot.
