It is so funny that you ask this, i was reading a book yesterday about this and most everyone is right when they say the only way to tell what leaves the track is if you watch them make it....However, if you have two to three inches of snow, bucks (buttons up to trophys) all drag their hind feet when they move them towards the front so if you see a drag mark to the rear paw in the snow it says there was a buck there, just no way to tell what size.