Find this full article by Kip Adams, Quality Deer Management Association (now recognized as The National Deer Association) – In Our Fall 2019 Issue of the Union Sportsmen’s Journal

Harvesting white-tailed bucks based on age is becoming an increasingly common management strategy. Hunters can accurately age bucks on the hoof based on their body characteristics—an ability many considered impossible not so long ago. With practice, hunters across the whitetail’s range can estimate the age of a buck as a means for selective harvest within Quality Deer Management (QDM) programs or merely for the fun of it. 

Why would you want to protect some younger bucks from harvest?

When a deer population is socially balanced, with all ages represented, hunters witness the full range of social behaviors. Rubs and scrapes are more common in the woods. Hunters witness more buck fights, see more bucks chasing does, and often hear vocalizations like grunting. Calling techniques like rattling are more productive. Overall, the rut is more obvious and intense, leading to a more enjoyable hunting experience and higher hunting success. There is also a better chance of seeing and harvesting a mature buck because more are present. 

Like humans, whitetails show signs of aging. While some body characteristics change by season, fall is the best time to age bucks because of pronounced neck swelling and tarsal staining. You can estimate age at other times of the year, but many characteristics are viewed relative to what they will (or did) look like during the rut. 

How To Tell The Age of a White-Tailed Buck On The Hoof

Fawns

Buck fawns are easily distinguished from other bucks but are commonly misidentified as female deer. Buck fawns have small square bodies, small short heads and relatively large ears. Their heads are flatter between the ears rather than rounded like that of a doe. The distance from their ear to eye is also approximately the same as the distance from their eye to nose. In contrast, the distance from an adult doe’s ear to eye is much shorter than from its eye to nose. Fawns also have short necks, flatter bellies and backs, and less muscle definition than adult does. 

1½ years

 

For most QDM programs, especially those in beginning stages, learning to identify yearling bucks is the most important aging skill. Yearling bucks have long legs, a thin neck, a slim body and a lanky appearance. Their legs appear too long for their bodies because their torsos (stomach, chest and neck) are not fully developed. Their antler spread is nearly always less than the width of their ears when their ears are in an alert position. They have a distinct line of separation between their neck and shoulders and little muscle definition. They have a thin waist, and they may have slight staining in their tarsal glands during the rut.  

 

Overall, a yearling buck looks like a doe with antlers. In well-managed populations on high-quality-habitat, yearling bucks can have large bodies and even 10 or more antler points, but the above characteristics will be present and can be used to separate them from 2½-year-olds. Study body characteristics before considering antler size when attempting to age a buck. 

2½ years

Two-year-olds have legs that still appear too long for their bodies, and they still have an overall sleek appearance. They have some muscle in their shoulders and slight swelling in their neck during the rut, but their waist is still thin. Given adequate nutrition, their antler spread can be equal to or wider than their ears. Finally, they can have moderate staining in their tarsal glands during the rut, especially if few mature bucks are in the population. 

3½ years

Three-year-olds have legs that appear to be the right length for their bodies because their torsos are now more fully developed. They have muscled shoulders and a highly swollen neck during the rut, but their waist is still lean. I liken three-year-olds to middle linebackers as they are big and strong but also lean and fast. A deep chest and lean waist give them a “racehorse” or “front-heavy” appearance. Their antler spread can be even with or wider than their ears. Research shows that, at this age, most bucks have achieved 50 to 75 percent of their antler-growth potential. They also have a lot of tarsal staining during the rut. 

Beyond 3½ years of age, determining the exact age of a buck becomes more difficult because of increased variation among individual bucks. However, for most QDM programs, harvest goals can be achieved if hunters are able to confidently separate bucks into one of three groups: A) Yearlings, B) 2½-year-olds, and C) 3½ or older. Hunters who want to sort and select bucks based on ages older than 3½ can still do so, but more time spent studying each buck may be required.  

What’s the best way to do this? Live-study in the field. Trail-camera photos and home-video footage can refine your estimates. Also, once a buck has been harvested, check its toothwear and/or cementum annuli ages from a reputable lab. This will help you hone your skills at aging the deer in your region or habitat type.

4½ years

Most four-year-old bucks have legs that appear too short for their bodies. They have fully-muscled shoulders, heavy swelling in their necks during the rut, and their waists drop down to become even with their chests. Given adequate nutrition, they’ll become structurally mature and can reach 75 to 90 percent of their antler growth potential. They also have a lot of tarsal staining and, during the rut, the stain may extend below the tarsal gland. Four-year-olds have an entirely different appearance than one- to three-year-old bucks. 

5½ to 7½ years

Few free-ranging bucks exceed five years of age, so I’ll combine five-to-seven-year-olds. Bucks in this category have legs that appear too short for their bodies. They also have several other characteristics of four-year-olds, including fully muscled shoulders, heavy swelling in their necks during the rut, and waists that are even with their chests. They may have pot bellies and sagging backs. Their increased body mass gives them a more rounded appearance, and they often look like a small cow. They will have achieved 90 to 100% of their antler growth potential, and they can have highly stained tarsal glands during the rut, with the stain extending well below the tarsal gland. 

As you study age-specific body characteristics, you’ll notice there aren’t age-specific antler characteristics (other than the range of antler potential that may be reached at each age class, and this percentage can’t be accurately estimated by viewing the antlers). Therefore, I suggest you don’t rely solely on antler size when aging bucks. Large antlers on a younger deer and small antlers on an older deer can negatively influence your estimated age. I prefer to estimate age based solely on body characteristics with respect to location and time of year and then use antler size to “check” my estimate or to break a tie if I can’t decide between two ages.  

 

For more assistance, I recommend the book “Observing and Evaluating Whitetails” by Dave Richards and Al Brothers, as well as the pocket field guide to aging bucks, produced as a companion to this book. Also, QDMA (now The National Deer Association) has produced an educational poster, “Estimating Buck Age,” that uses photos of live bucks of known ages to illustrate variations in body characteristics by age class. These items are available at The National Deer Association website

Aging bucks on the hoof is a lot of fun. Whether you hunt with a bow, sporting arm or camera, this information can make you a more knowledgeable whitetail enthusiast. 

 

Kip Adams of Pennsylvania is a wildlife biologist and the Director of Conservation for The National Deer Association (Formerly QDMA – Quality Deer Management Association)

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