ORIGINAL: MOTOWNHONKEY
Good theories but you only see it after the antlers are in full display each year. I never seen a doe with a bald back.
I seen it with me own eyes mates!
I agree with MOHO, that and using licking branches like GregH said.
Like MOHO, you never see immature bucks (small antlers) or does with the bald spots. Only a good set of antlers can reach that spot.