How to Age and Field Judge A Deer

Trailing a doe, a heavy racked 8-point whitetail was beelining straight for me. Best guess, based on body size, better than average antler mass, width, and height, he was probably a year away from meeting his genetic potential. It’s a dilemma every big buck hunter faces – to shoot or not to shoot?

He could grow some more, but no guarantees. His musculature, girthy chest, and sway belly told me he was mature. It was late in the season, so I opted to take him. At full draw, as he walked just 15 yards from the base of my tree, I centered my sight pin, and sent an arrow on its way. He ran the standard 40-yard sprint, turned and toppled, bringing my hunt to an end.

Over the last decade especially, I’ve worked hard at targeting mature bucks, particularly those that are at least 4.5 years of age. Older is better, but in western Canada, senior bucks are few and far between. If quality deer management is a priority, it’s important to let younger bucks go, so they can grow. Harvesting immature deer is counterproductive if you’re goal is to manage for big-antlered bucks.

Aging A Deer

Contrary to what many hunters think, aging isn’t about the number of tines or thickness of the antlers. I’ve heard many hunters speak of a 2×2 rack suggesting the deer is two-years-of-age, a 3×3 being three-years old, a 4×4 being four and so on. Much like people come in different shapes and sizes based on genetics, so do deer. Antler mass, width, and the number of points can, to some extent, be used as an initial reference point when aging deer, but these characteristics are more about genetic strength than age. Indeed, it is more common to find older, healthier, and stronger deer sporting impressive racks, but I’ve also seen 3.5-year-old bucks holding truly spectacular headgear. In fact, I once guided a hunter from the states, who tagged a trophy whitetail that renowned deer biologist, Dr. James Kroll, determined was just 2.5 years-of-age. That buck scored an impressive 184 inches B&C.

Beginning with the youngest, here are a few pointers for aging deer. Fawns are rarely without their mothers, and 1.5-year-old button bucks often hang with their siblings or their mothers as well. Straightforward to judge, look close enough and you’ll see nubs, or what appear to be tufts of hair protruding slightly forward just between the ears. The impressive thing with antler growth is that bucks generally continue to grow larger and larger racks until they reach maturity. In fact, most will reach their genetic potential around the 4.5 and 5.5-year mark. After that, its really all about health, environmental conditions, diet, and corresponding strength. Once they peak, just like with humans, their overall antler size and physical stature morphs and ultimately deteriorates.

While we as trophy hunters make much ado about antlers, aging whitetail and even mule deer on the hoof, for instance, is most accurately done by looking at their physique, in other words their skeletal frame and body mass. The first thing to evaluate when aging a deer is its frame and torso. When a buck reaches 2.5-years of age, the same as with human adolescents at puberty, we begin to see signs of genetic potential. At this age, a buck will have longer more slender legs, that sometimes look a bit awkward relative to their similarly trim body.

One of the key characteristics of the torso on a young buck is a more sleek, slender, or streamlined belly and chest. These are still young deer, and they are generally easy to identify. If you want to strengthen the heard, leave these ones alone and hold out for something older. A mature deer’s chest and belly fill out making their legs appear shorter. They look that way because their body has developed more depth and girth. A young deer’s chest will taper back to its waist, similar to the physique of a young human athlete. At early maturity, from 4 years on, their chest fills out and the tapering typically disappears. From 5.5 years on, they will often gain a more rounded pot-bellied appearance.

One of the most common tell-tale signs of an older deer is a thick swollen neck during the rut, which incidentally is when the majority of hunters tend to be in the field looking to close a tag. Although not always the case, a massive neck is a strong indicator of age at this time of the year.

This is one of those bucks that requires no decision. Notice the sway belly. Clearly older and the antlers are impressive. The author passed this buck up in November of 2022 at 27 yards and hunted him in 2023, but this video was the last he saw of him.

By comparison, a young deer’s face and nose is usually slenderer and appears to be longer. An older, more mature deer’s face broadens giving the nose a shorter, more boxy appearance. Sometimes the hair on the forehead of an older buck will look a bit gray as well but not always. If you’re lucky enough to get a close-up side view either from a stand, ground blind or through optics, the skin or jowls of a mature deer will tend to sag somewhat, just as they do on aging people.

No guessing necessary here. This young buck has all the tell-tale features of a 2.5 year old. Can’t wait to see what he grows into.

Last but not least, how a deer moves can be another reliable indicator of age. Again, consider the comparison. As people age, we are conservative in our movements. We are less spry and much more calculated. So too are mature deer. While younger deer may bounce around and scamper around, older bucks are more intentional and by description less agile in their movements. A good analogy involves listening to deer walk through the dry leaves in the fall. A younger deer will usually be lighter on its feet and move quicker, while a mature buck, one that’s bigger and heavier, will often move slower. He knows he’s bigger and louder. As such he is often more intentional about his movements. With a bit of experience, you can usually tell long before seeing a buck – just by listening to the steps, whether he is a younger or older deer.

Once you’ve looked at the face, nose, body and legs, its time to evaluate the antlers to properly field judge what that deer really is.

Field Judging Deer

Deer hunters universally talk about the number of tines or “points” a buck has. Stateside, hunters tend to refer to a point total for whitetails and points per side for mule deer, e.g., a mainframe 8-pointer, 10-pointer, and so on. On a whitetail, this includes the eye guard, but this is generally not the case with mule deer. For mulies, we often describe them as a 4×4, 5×4, or whatever other tine count the deer’s antlers have. With a little practice, it becomes easy to field judge the number of points a typical buck has at a glance. Those with typical headgear, i.e., a rack that is symmetrical and without non-typical points (i.e., stickers and forks), can be simple to identify. Add drop-tines, sticker points protruding in a non-typical fashion, or double eye-guards, and suddenly that buck becomes more difficult to field score. That said, these antler anomalies often develop with age. So, if a buck has these, you could be looking at an older deer.

Antler mass can really mess with your mind. Remember that the base of the antlers or ‘pedicels’ continue to grow or get wider until maturity at 4.5 years of age, and sometimes older. Both whitetail and mule deer antlers grow in all shapes and sizes. Typical mainframes have similar configurations, but some are heavier than others. Most of us drool at the thought of heavy racked deer. That’s one of the advantages of hunting big bucks. Mass refers to the overall girth, or in scoring terms, circumference of the bases, main beams and points. When you see a buck on the hoof, take notice of his antler mass. Do your best to guess the circumference of his bases. An average buck in the 120-inch to 130-inch class will often have bases measuring between three to four inches in circumference. In areas with strong genetics, particularly in some mid-west states and Canadian provinces, heavy-racked bucks will often have circumference measurements at the base of over five inches.

The side-to-side spread between the right and left antlers is the width and it generally takes into consideration the widest distance between the main beams. This can be tricky to determine as well given that you need a head-on or rear view in order to get a true picture of the buck’s spread. Most whitetail bucks, again in the 120- to 130-inch class will have an inside spread of around 17 inches. Anything over 20 is considered big. Once you hit that magical 24-inch spread, chances are you’re looking at a book whitetail. Likewise, with most northern mule deer in the 130- to 150-inch class will have a spread of around 23-25 inches. All else being equal, any antlers reaching the 29- or 30-inch width are likely entering the trophy category. Like people, deer have different sized heads and ears, but as a rule if the buck’s ears are pointed straight out to the sides, and his antlers are outside his ears by more than a couple inches, chances are pretty good that his spread measurements will be equally impressive.

High scoring deer are not always tall, but height or “tine length” definitely helps with bottom line score. If you’re looking at a buck on the hoof and he’s got tines that measure over 10 inches, chances are he’s worth further consideration. In my opinion, once you get a whitetail buck with tines, particularly the G2s and G3s measuring over 12 inches in length, he may be a keeper. Rarely do we find G4s measuring over five inches, but if you do, definitely consider hitting the switch. Likewise, with mule deer any time I see a buck with deep forks, i.e., 12-inch or better tines I’m interested in giving that buck a closer look.

Again, when we are field judging a buck, body size is a great first-glance indicator as to the age of the deer. To recap, smaller slender bodies are characteristic of young deer in the 2.5 to 3.5-year age class. Deer in the 4.5 to 5.5-year age class will begin to look much larger with a bigger chest, and they’ll generally have more body mass all around. Mature bucks over 5.5 years of age will often be close to double the overall body size of does and may even begin to show a slight sway back in their posture.

Definitely a mature deer. He’s got height, plenty of points, and width … just missing the mass. All told though, he’s a shooter.

As hunters, we commonly hum and haw about whether or not to shoot. Most often a buck takes some assessment to accurately estimate its trophy quality. Then there are those that require no second look. The “wow factor” is immediate and undeniable. Even at first glance, they are impressive, i.e., surpassing the all-time book minimum of 170-inches for whitetails and 190-inches for mule deer.

For most of us, our dream buck has all of the above – namely an enormous, old, chunky body with a heavy wide, tall rack with too many points to count at a glance. Remember, if he’s got a heavy looking bulky form, legs that appear to be shorter, a big ‘ol swollen neck, a boxy looking face with a shorter nose, and heavy impressive antlers … well, it’s time to settle those crosshairs and make your shot count. If you’re lucky enough to bring down a buck of this description you’ve beat the odds and can not only fill the freezer but put a mount on the wall as a reminder. Most trophy bucks have at least a couple of these characteristics, but few have them all. The next time you’re in the field, consider the importance of aging deer relative to managing your herd. Recognize these field judging tips, and you’ll be well on your way to taking home a mature trophy.