How to Age a Deer and Why It's Important

While there is plenty of available data, charts, and information on aging deer, we hope the info below, as well as our whitetail deer aging chart, can help you learn how to age a deer on the hoof before your next hunt. And if you successfully harvested a deer, we provide three additional aging techniques to determine deer ages.

Reasons to Learn the Age Class of Deer (Before You Shoot)

Aging whitetail deer isn’t necessary for general deer hunting goals. It won’t make you more successful at putting meat in the freezer during or after hunting season. But for those who choose to target older, more mature bucks, estimating age is a skill you must master.

Those who aren’t confident with their ability to age deer in the field on the fly should start by aging deer within trail camera photos. Then, if they see the deer while hunting, they’ll already know if they plan to shoot or not.

Of course, there are plenty of reasons to age a deer and ensure it’s an older member of the herd before shooting it:

1. If you want to shoot a mature deer, you must ensure it is one before sending a bullet or broadhead downrange.
2. If managing land for older bucks, identifying a deer as a young buck, and subsequently passing on it to allow it to reach a more mature age class, is necessary.
3. Passing on younger bucks means more and bigger bucks to see and shoot in the future.
4. Allowing bucks to age gives them time to express and spread their antler genetics.
5. Not shooting younger bucks — and taking the correct number of does — helps balance the buck-to-doe deer population ratio.
6. Allowing bucks to get older creates a balanced, natural age structure for the deer population
7. Having a balanced age structure improves the overall deer herd.
8. Improving the buck age structure increases the overarching area’s hunting (and land) value.

On a side note, if you're tracking numerous bucks and following them over a number of years, it's hard to beat DeerLab's Profiles. It's an excellent tool that can help you with your deer management. The service allows you to track individual bucks or even groups of bucks, keeping logs of their activity and movement, as well as seeing a buck's historical growth over time. One lesser-known feature is Albums. This is helpful if you want to share your trail cam photos (without all the stats DeerLab gives you), say just of your hitlist bucks or photos of mature bucks, with others, so they can help you with your deer management.

Aging Deer on the Hoof: Characteristics of Age Classes

While it's not likely to age doe on the hoof, keying in on whitetail bucks body characteristics can help you make an age estimation.  Each buck exhibits unique antler, body, and personality traits. However, certain body features tend to consistently change with age and exhibit features tethered to particular age groups. Because of this, it makes aging deer possible. Aging deer on the hoof won't tell you the exact age, but it will within a year or so of its actual age, and this can help deer management.

Some deer body parts to look at when trying to age class a whitetail deer on the hoof include the antlers, back, belly, head, legs, neck, and tarsal glands. Each of these changes over time, and how they look can provide clues as to what age a deer is or isn’t.

Age Estimate: 1 ½-Year-Old Buck

Also referred to as yearling bucks, a 1 ½-year-old resembles a small doe with antlers. Antler size has only reached approximately 20-30% of overall potential and is likely a spike, four-pointer, six-pointer, or very small eight-pointer. Regardless, the spread for younger deer will remain inside the ears.

The head appears long and slender. Body weight distribution is more toward the rear end. The back line appears to slope downward from back to front. The belly and back of the buck do not sag. The deer’s neck has no swelling. Legs seem to be very long compared to their torso. Tarsal glands are lightly stained.

Age Estimate: 2 ½-Year-Old Buck

Once a buck reaches 2 ½-year-old status, it’s synonymous with large does with antlers. It often grows antlers with a spread just inside, at, or just outside the ears, and it’s likely sporting about 50-60% of its lifetime antler potential. Often, it grows between six and 10 points, with a typical average number of eight points.

The head is still long and slender. Body weight distribution shows a heavier rump than front end. This age bracket has a backline that still slopes from the rump to the shoulders but has no sagging of the back or belly. The buck’s neck is generally slightly more muscular than the year before, but no severe swelling occurs. The legs still look too long for the body. Tarsal glands are somewhat stained.

Age Estimate: 3 ½-Year-Old Buck

Now we’re beginning to see some size. This is the age bracket when a buck starts being classified as “big.” It almost always has an antler spread outside the ears and expresses decent mass and good tine length. This buck sports approximately 70-80% of antler potential.

As for the body, the head still appears elongated, but it’s getting thicker from top to bottom, too. It now has a straight line across the back from rump to shoulders (no downward angle or sagging). It has a tight belly line. Weight seems to be distributed evenly from front to back. The neck begins to swell considerably, especially compared to 2 ½-year-old bucks. Legs finally look proportionate to the body. Tarsal glands are moderately stained.

Age Estimate: 4 ½-Year-Old Buck

While a 4 ½-year-old deer is close to being fully mature, it still has much potential to express. In fact, on average, it only grows approximately 80-90% of its antler potential. That said, it exhibits impressive antler size, and begins showing exceptional antler mass, tine length, and more.

The head is now blockier than it once was. Its weight distribution is mostly even from front to back. This age bracket still has a straight line across the back and belly. The neck has significant swelling. The legs still look mainly proportionate to the body. Tarsal glands are heavily stained.

Age Estimate: 5 ½-Year-Old Buck

No hunter can argue that a 5 ½-year-old deer isn’t mature. This animal expresses most of its antler potential, sporting about 90-95% of it, and its body is huge. Antlers generally display incredible mass, beam length, tine length, etc.

Its head appears shorter and thicker than ever before. Weight distribution seems to shift more toward the front of the body. The backline is still straight from rump to shoulders but might show slight swaying. The belly might do the same. The neck shows heavy swelling, and the legs appear too short for the body. Tarsal glands are very heavily stained.

Age Estimate: 6 ½-Plus-Year-Old Buck

Now a bona fide mature deer, a 6 ½-plus-year-old buck’s body is taking on a new shape. It now carries approximately 100% of its antler potential but could grow its largest rack at age 7 ½ or 8 ½. This deer is distinctly different from younger bucks. The difference can be quite staggering.

Its head appears very short and very thick. Weight distribution makes it seem as if the buck’s front is much heavier than the rear end. The back and belly exhibit significant sagging. The neck is extremely swollen. The legs appear much too short for the body. And tarsal glands are extremely stained.

Aging a Harvested Deer

Hunters aren’t limited and restricted to aging deer on the hoof. Although there is no catch and release in hunting, hunters can certainly ground check their bucks, too, which is the act of determining the size, age, and gender of a deer or other game species once it is dead. There are two good ways to do this and a third option that works for supportive reassurance.

Skull Plate Thickness

Speaking of supportive efforts, those who skullcap their bucks will notice older deer exhibit significant increases in skull plate thickness. Generally speaking, the older a deer gets, the thicker its bones and skull plate becomes. The skull plate for young deer is more fragile, while older deer have thicker skulls. In theory, the skull plate aging method works, but when aging deer this way, it's difficult to measure and it's definitely not an exact science. If you want to be more accurate, tooth replacement and wear, as well as cementum annuli are the best routes to go.

Tooth Replacement and Wear Method

In contrast, tooth replacement and wear is an excellent and more common method for aging bucks after the harvest compared to on the hoof. This method was developed by C. W. Severinghaus in 1949 (1) and is sometimes referred to as the Severinghaus technique. The bottom jaw changes as deer age. The first step in determining the age of a deer with the tooth replacement and wear technique is counting teeth. Here's a breakdown centered around tooth characteristics, as well as a video going through deer teeth wear from the Pennsylvania Game Commission.

Fawn Teeth

Fawns have five (or fewer) jaw teeth, and the third premolar has only three cusps. For a fawn 3 to 4 months old, either the first molar is just starting to show, or isn't showing yet. A fawn that's 4 to 6 months old has its first molar erupted but its second is not seen. For fawns that are 7 to 9 months old, the second molar is now starting to show or fully erupted, but the third molar can't be seen.

1½-Year-Old Deer Teeth

Deer or yearlings that are 1 ½-years-old likely have six jaw teeth along the bottom jaw, the third molar is starting to show, and the third premolar tooth has significant wear, having three cusps.

2½-Year-Old Deer Teeth

Once it reaches 2 ½, the third tooth has only two cusps, and the crests are sharp and pointed. There is minimal wear showing on molars.

3½-Year-Old Deer Teeth

At 3 ½, the slight wearing of the permanent teeth is visible, and slight concavity is present. The cusps of the first molar show substantial wear and the third molar is fairly level.

4½-Year-Old Deer Teeth

Most 4 ½-year-old bucks exhibit noticeable tooth wear and often slope heavily downward toward the jawbone. The cusps on the first two molars will have significant wear.

5½-Year-Old Deer Teeth

The same holds true for 5 ½-year-old deer, as the teeth become significantly blunted and worn. All three molars will show significant wear.

6½-Year-Old Deer Teeth

Once deer reach 6 ½ and older, the teeth are worn down smooth, or flattened, and little enamel shows. Eventually, the teeth will wear down very close to the jawbone.

Cementum Annuli Aging

Lastly, the best and most accurate method for aging deer is called cementum annuli (CA).  In short, cementum is the connective tissue that forms on the root surface of most teeth.

During the life of a whitetail, as well as other mammals, cementum forms layers or rings, similar to growth rings that you would see in tree trunks. These rings are visible microscopically and form a pattern that wildlife aging experts can use to determine deer ages.

To have a professional age your deer, you would need to remove teeth from the lower jaw and send them off to be examined in a laboratory setting. Once there, the lab studies the teeth and tooth wear to age them. It costs approximately $50 per deer, and two of the most used labs include Matson’s Laboratory and Wildlife Analytical Laboratories.

Appendix

Cementum - A protective hard tissue that surrounds the root of each tooth.
Anulli - Layers that are formed over the root of a tooth that are used in the process to age individual deer.
Cusps - A point or ridge of a tooth, when viewed from the side.
Crest - The top of the cusps or ridges of a tooth.
Dentin - That part of the tooth that is beneath enamel and cementum
Enamel - The white part of a tooth.
Molar - The three permanent teeth in the rear of the deer's jaw.
On the Hoof - Alive, not yet harvested.
Premolar - The three teeth in front of the jaw that are replaced by permanent teeth.
Skullcap - The top part of the skull.
Tarsal Gland - Found on bucks and does, the tarsal gland is a pad of stiff hairs located on the inside of each deer's rear leg. The gland secretes an oily material that coats the hair, making it darker.

References Cited

1. Severinghaus CW. Tooth development and wear as criteria of age in white-tailed deer. Journal of Wildlife Management. 1949;13(2):195–216.