Northern Prairie Wildlife Research Center
Deer in North Dakota are primarily born in late May and early June. Therefore, when most deer are harvested in November they are either six months, 1-1/2; years, 2-1/2; years, 3-1/2; years, etc., in age. This guide is designed to block deer into these age categories.
The overall age structure of a hunted deer population is younger than most people think. During the fall of 1995, the Game and Fish Department operated 15 check stations in southeastern North Dakota. Of 790 deer aged at these check stations, 80 percent were 2-1/2; years old or younger.
Antler and body size can indicate a deer's age, but physical characteristics are often misleading. The number of antler points in no way corresponds to age. Even if it did, it wouldn't help in aging does, which make up a considerable proportion of the harvest each year.
Antler size in bucks and physical development in both genders is greatly affected by diet and genetics, which may account for differences between animals of the same age taken from different locations.
Deer in eastern portions of the state, where row crops are more common, are often heavier bodied. Six-month-old deer (fawns) may at first appear older, and yearlings (1-1/2; years old) may approach 140 pounds field dressed.
Like humans, deer replace their "baby teeth" with permanent teeth at a relatively set rate. As surely as a 6-year-old child will soon lose her two front teeth, an 18-month-old buck will be in the process of losing its third premolar.
By the time a deer is 2-1/2; years old, all permanent teeth are in. At this stage, estimating age is based largely on the rate of tooth wear. Diet and soil types may accelerate tooth wear, but generally, estimating the age of adult deer is straight forward until they reach age 5-1/2;. Beyond that, estimating age by tooth wear is less reliable.