Following the period of life when sexual activity is greatest, the size of the antlers generally dwindles with each year's renewal until an old deer may have only spikes. Abnormally shaped antlers occur occasionally and sometimes represent injury during growth. An upset in the hormone system is one factor which is probably responsible for unusual cases of antlerless bucks or for females having antlers. In some cases, antlerless bucks are the result of hereditary factors. Hunters count all of the points, including the snag on both beams, in arriving at the total number of points on a trophy set of antlers.
Fawns are reddish, brown or reddish yellow spotted with white.
They gradually lose their spots and acquire uniform coloration between 3 and 5 months of age. Among similar-aged individuals, female weight averages lighter than male. Deer from the fertile soils of north Missouri weigh more than those of the same sex and age from south Missouri. The sex of a deer cannot be determined by its track, because there is no constant difference between the size and shape of buck and doe hoofs. During the breeding season, the necks of males swell to approximately twice their nonbreeding size, reaching a maximum in mid-November.