I have not heard of fallow being called stags - I think that is a regional colloquialism (i.e. they got the name wrong!

). I was always taught that male fallow were called (according to age) 1st year -
fawn 2nd year - pricket 3rd year - sorrel 4th year - sore 5th year - buck (sometimes buck of the first head); 6th year - great buck I think most antelope are called rams and ewes - they are not deer and like sheep have horns rather than antlers. Bull and cow are names which come from cattle and so these common names where probably attributed to large deer and antelope because of the size of the beast. Whether it is correct or not is a different matter - for example a Maral is essentially the same animal as a wapiti or american elk, but the former is a stag and the latter a bull. Lets not even get started on why on earth an elk in Sweden is not an elk in north america, but rather a moose! But as to stag and buck, this may have had something to do with the esteem with which the animal was held as a hunting quarry and also the class of person hunting them - after all a rabbit is also a buck and doe and roe deer did not really have the status and protection of a 'game' species until sometime in the 1960s...