Outdoor Life Online Editor

“Man, look at that rack!” I hollered.

“To heck with the horns, check out that keg belly and sway back,” drawled Fred, my grizzled, 70-something guide. “That deer is at least six and a half, maybe seven and a half.”

I glassed the gnarly animal up and down. He oozed “old” all over. That hunt with Fred in Texas years ago was a turning point for me. Now when I go in search of a truly old buck, I check his antlers and his physique before I release the bowstring or pull the trigger.

Full-Body Scan
During a 13-year study, deer biologist Mick Hellickson and his team used net guns to capture 766 free-roaming bucks of various age classes on a South Texas ranch. Before releasing the animals, the researchers measured their bodies and racks. The 1½-year-old deer averaged 115 pounds on the hoof, while the 4½-year-olds tipped the scales at about 175. Remember this: Any buck that looks like it weighs 50 or 60 pounds more than the others in the area is mature and likely a shooter.

Glass a lean deer with a thin neck and long legs, and you can bet he’s a yearling or a 2½-year-old. Whitetails age like we do. The older they get, the thicker they get. As a buck turns 3½ and especially 4½ or 5½, his chest and sides bulk up and out and his neck swells and blends into his body. He looks like one of those blocky, muscle-bound lifters at your gym. If a deer is fortunate enough to survive to 6½ or 7½, he might get a sway back and lose his hips, just like an old horse.

After analyzing the stats of all the bucks in his study, Hellickson determined that the best body characteristic for estimating a whitetail’s age is stomach girth. When a buck turns broadside, glass the bottom of his body. “If the belly sags noticeably lower than the bottom of the brisket or chest, the buck is mature,” says Hellickson.

[pagebreak] Rack Check
Now all of this doesn’t mean you don’t want to eye that rack, too. A buck can go from a fatso in September to a lean, mean doe-breeding machine in November to a shell of an animal in the post-rut. As his body changes, it can be tricky to pin down his age. Except for maybe a broken tine, however, a deer’s antlers stay the same throughout the fall. According to Hellickson, checking a buck’s headgear is still the most reliable way to determine his age on the hoof.

A deer with a noticeably big rack for your area-long main beams, eight or more long tines and heavy mass-is at least 3½ years old and likely 4½. When a buck faces you, glass closer yet. In Hellickson’s analysis of more than 750 sets of antlers, the inside spread averaged 7 inches for yearlings and 13 inches for 2½-year-olds. That measurement shot up to 16 to 18 inches for deer 4½ and older. If you see thick antlers well outside the ears, the buck is a shooter-take him!

How Old Is He?
1½ years old
* Looks like a doe with antlers
* Lean body; no defined muscles
* Long legs
* Long, thin neck
* Spike to 6- or 8-point rack; inside spread 7 inches or so; main beams 8 inches; thin mass

2½ years old
* Thin shoulders and waist, though a little thicker than a yearling
* Noticeable junction between the deer’s neck and chest
* Limited neck swelling during rut
* Nicely developing antlers, but mass is still light; the average inside spread for a deer of this age is 13 inches with 15- to 16-inch beams

3½ years old
* Thick chest appears deeper than hindquarters
* Neck swells during rut, but there’s space between the buck’s neck and shoulders
* Looks like a well-conditioned racehorse
* 8- or 10-point rack; the inside spread is 15 inches or more; the main beams are 18-plus inches; the antlers have good overall mass

4½ years old * Muscular neck blends into the deer’s shoulders
* Thick chesst and sides; body has an overall blocky look
* The buck has a pot belly that may sag down well below its brisket
* Short, thick face with “squinty” eyes
* 8- or 10-point rack 80 to 100 percent developed; inside spread of 16 to 18 inches or more; main beams are 20-plus inches; heavy mass

The Quality Deer Management Association’s Selective Buck Harvest poster is a great resource for estimating the ages of whitetail deer ($9.95; qdma.com). You can find it in the online store’s poster and maps section. Refer to it often to get better at aging bucks on the hoof.