I spotted this head sticking up amongst the tall meadow grass in the evening light. Depending on where you live, this is a woodchuck, groundhog, or whistle pig. I just like this scene for some reason. Let me talk about it briefly...
This photo has not been cropped at all. Obviously, the groundhog does not fill the frame. Many times I think we worry too much about having that frame filling head shot when it comes to wildlife. In doing so, we sometimes miss out. We all know what a groundhog looks like. I would argue that the groundhog is not the sole subject here, but rather the groundhog AND his immediate surroundings. It's also obvious I broke the rule of thirds where the groundhog is concerned. I actually like the rule of thirds most of the time, but in this case, having the groundhog in the center better conveys the vastness of the meadow grass around him. I'm shooting into the setting sun which is usually not the best angle, but I like the effect in this case. You can even see plant particles floating in the air. I determined this was the most pleasing composition to achieve what I wanted to convey.
Now compare the top photo with this one below. I have adjusted the composition to better suit the rule of thirds for the groundhog. But look what happened. Now there is a road sign in the shot and a horse running in the background, both of which are distracting and not very pleasing. In addition, moving the groundhog to the left of the scene doesn't quite have that same effect of being surrounded by the tall grass even though he still is. I have completely changed the feel of the scene just by moving the camera a little bit. For me personally, the top photo is much more pleasing even though I broke a couple of rules because the overall composition trumps the rules I broke.
I simply wanted to convey a couple of things. First, don't get so hung up on trying to get that frame filling head shot that you miss out on a bigger picture. Those eyeball shots are nice, but not always the best photo. And second, composition is everything even if you break some rules in the process.