RE: How can you tell the age of a deer?
Well, if you are trying to avoid the "gee c_str, did you have to drag your deer out, or just stuff it in your coat pocket like a partridge" comments, here is the rule I use.
It's the box rule. Draw an imaginary box around the deer, touching the nose, top of head, tail and feet.
If your ending drawing is more like a box, then you are looking at a fawn, or a very young deer.
If your ending drawing is a rectangle, start shooting! It's a full grown animal.