Jim
There's a thread on critter sizes on this board somewhere. One thing that came to light is that there are easily two different sets of measurements for use... Just behind the shoulder on a deer or more rearward at the ribcage/stomach area. For deer I've actually measured here locally small does ar in the 14 to 15 inch range (behind the shoulder) and a very large buck would be 16 to 17 inches. An 18 inch whitetail buck (or doe for that matter) would be a very large deer.