Aging Deer- This might help....
The 1½-Year-Old Buck (Yearling)
It is often said a yearling buck resembles a "doe with antlers," which makes it relatively easy to discern. The 1½-year-old buck will not develop the swollen neck and muscular characteristics of older bucks. These bucks tend to have thin hindquarters and long, thin legs. Think of a teenaged boy, not yet reaching full height and not nearly "filled in."
Almost all yearlings have an antler spread less than 13 inches. These "teenagers" have not learned to be as secretive as their older associates are, so they often enter food plots earlier than older bucks and tend to be in the vicinity of doe family groups. The average size of a buck's antlers doubles between 1½ and 2½ years of age, so it is a good decision to let a yearling buck grow at least another year.
2½-Year-Old Buck
The 2½-year-old group is more difficult than yearlings to judge. The majority of this age group still have antler spreads inside the ears, but some individuals may produce a good set of antlers. During rut, this age class produces a limited amount of neck swelling due to muscle development, and the waist, or area just in front of the back legs, is relatively thin. Their hindquarters are much more filled in than the yearling's, but their legs appear to be "long and lanky." This age class has lots of growing to do before reaching full maturity, so it is best to let them grow at least another year. Their racks are only about 60 percent of the size they will be at 5½ to 6½ years.
3½-Year-Old Buck
The ability to distinguish 3½-year-old age group is important to a management program emphasizing harvest of mature-aged bucks with maximum antler development. During the rut, the buck's neck is thickly muscled, yet there is still a distinct junction between the neck and shoulders. Some biologists compare its look to that of a well-conditioned racehorse.
The chest region may begin to appear deeper than the hindquarter area; inside spread of antlers typically is at or outside the ears. These bucks can develop impressive antlers, especially on well-managed properties in productive habitats; they are easily mistaken for "mature" deer. In reality, they have reached only about 75 percent of maximum antler development.
4½-Year-Old Buck
A white-tailed buck physiologically matures by 4½ years of age. By this age they have almost all of their adult body mass and have lost the racehorse look. Its neck region is fully muscled, giving the appearance of blending into the shoulders, and the waistline is as deep as the chest. Buck activity patterns may have changed by this age due to an increased wariness; they may not venture into open areas until about dark. Physiological maturity is closely associated with the maturing of a buck's antlers. By this age, the average buck will have grown about 90 percent of his total antler size.
5½- to 6½-Year-Old Buck (Mature or Prime)
Fully matured bucks have a distinctive look that is undeniable once experienced. This publication groups deer 5½ years old and 6½ years old into one age class, because few hunters or managers will want to try to differentiate animals. Antler size typically is maximum at 5½ to 6½ years of age and may deteriorate thereafter, depending on forage conditions.
During the rut, the buck's neck blends completely into his shoulders, and his front half appears to be one large mass. His legs appear shorter than legs of younger deer, but this is an optical illusion because his chest is taking up more of the viewing area. Just as people in middle age, most mature bucks exhibit a sagging belly. Their eyes are squinty in appearance. Mature bucks often show battle scars such as torn ears, broken antler tines, and scratched necks.
7½-Year-Old and Older Bucks
Overmatured bucks are often mistaken for younger animals because some body characteristics tend to revert. Muscularity is lost in the neck area because these animals may not participate as frequently in normal rutting activities. A swayed back and a prominent potbelly are other signs of this aged buck. Loose skin develops on the neck and head areas as muscle tone declines. Recent battle scars may not be visible, but old scars such as slit ears are evident. A buck's antler size tends to decline with advancing age.