A photo model aged 4.5 bucks too old before the rut and too young after

STEP 1 · Ratio test

Fall photos pushed 4.5 bucks up and winter photos pulled them down

The known-age photo work measures body proportions on pictures with a research model. In the Journal of the Southeastern Association of Fish and Wildlife Agencies, Flinn and colleagues showed how those proportions sorted male white-tailed deer. They measured 64 ratios on captive bucks of known age and retained 12. One model uses photos from before breeding. Another model uses photos from after breeding.

Before breeding the correct calls were 75 percent for 1.5-year-olds, 86 percent for 2.5-year-olds, 40 percent for 3.5-year-olds, 0 percent for 4.5-year-olds, and 71 percent for bucks 5.5 and older. After breeding the correct calls in that same order were 88 percent for 1.5-year-olds, 71 percent for 2.5-year-olds, 53 percent for 3.5-year-olds, 14 percent for 4.5-year-olds, and 85 percent for bucks 5.5 and older.

Model building used captive bucks of known age in Mississippi and Oklahoma. Flinn and colleagues tested the models on 106 wild bucks of known age inside big fenced enclosures in Mississippi, Louisiana, Texas and Oklahoma. Most of the pens supplied extra feed all year. Pen size ran from 415 to 3,200 hectares. Thirty of the test bucks were on camera during September and October. Seventy-six were on camera during January and February. Fall counts from the 1.5 class through the 5.5 and older class were 4, 7, 5, 7 and 7. Winter counts in that same order were 17, 17, 15, 14 and 13. Just 7 of the fall bucks and 14 of the winter bucks were in the 4.5 class, so both the 0 percent figure and the 14 percent figure sit on small classes.

That 4.5 class is where camp arguments land, and calls on it were poor. Among the fall bucks aged 4.5 the model was right on 0 of 7 and put 6 of those 7 in the 5.5 class. Among the winter bucks aged 4.5 the model was right on 2 of 14 and put 8 of those 14 in the 3.5 class. Flinn and colleagues found the biggest miss before breeding was calling 3.5-year-olds and 4.5-year-olds as 5.5-year-olds. After breeding, bucks of those two ages were more often called 2.5 or 3.5. Keep the 0 of 7 and the 2 of 14 inside this study, because they are not a personal miss rate on deer in some other state.

Fall bins were right 75 percent of the time for yearlings, 70 percent for ages 2.5 through 3.5, and 86 percent for 4.5 and older. The oldest single class in the paper is 5.5 and older, so the wide fall group is 4.5 and older. Winter bins were right 92 percent of the time for ages 1.5 through 2.5, 69 percent for ages 3.5 through 4.5, and 85 percent for 5.5 and older. A cut between the 1.5 class and the 2.5 class was more than 80 percent correct. So was a cut between the 2.5 class and the 3.5 class.

STEP 2 · Live look

Yearling body cues line up with the cut the model could make

From a stand you read the neck, the chest, the belly and the legs. Demarais, Stewart, and Griffin wrote the Southeast field guide from the Mississippi State University Extension Service. The 1.5 buck sits on the young side of the 1.5-to-2.5 cut the photo model cleared past 80 percent. At that age the guide still draws a doe's body with antlers on the head. His neck stays slim and his legs still read as long. The guide says bucks this young are less apt to hide. They commonly reach openings before older bucks do and they linger with groups of does. Mean antler size in the guide doubles between age 1.5 and age 2.5, and that doubling is why it says to pass a yearling.

At 2.5 some muscle shows in the rump while the buck stays lanky and the rut barely swells his neck. At 3.5 the neck is heavy and still joins the shoulder along a crisp edge. The guide says hunters often call this buck mature. At 4.5 the racehorse shape is gone. The neck runs into the shoulder and the waist sits level with the chest. The guide bins 5.5 with 6.5 as one mature class. There the front end is one block and the belly hangs. Past 7.5 the neck grows slim again while a pot belly shows and the buck can pass for younger.

In a rushed shot the same guide says rack size is difficult to judge. Many mature bucks there never top 8 points or an inside spread of 16 inches. On rich ground a 3.5-year-old can already wear a rack that looks done. A tight spread may belong to a buck already at mature age.

University of Missouri Extension calls live aging an estimate. Its signs miss some bucks and accuracy falls with age. Missouri says most bucks can be told immature from mature with moderate certainty. Flinn and colleagues also recount an eye test Gee and colleagues gave 106 professional deer biologists at the 2009 Southeast Deer Study Group. They judged 583 post-breeding photographs of 70 wild Oklahoma bucks of known age. They were right on 62 percent of the 1.5-year-olds, 43 percent of the 2.5-year-olds, 25 percent of the 3.5-year-olds, 30 percent of the 4.5-year-olds, and 55 percent of the 5.5-year-olds.

For a Southeast check with binoculars the Mississippi State guide prints a few inch marks. Ears held relaxed measure about 15 inches across both tips. Ears pointed forward when alarmed measure about 12 inches. A single ear is near 6 to 7 inches from base to tip. The guide says "Almost all yearlings have an antler spread less than 13 inches." Passing bucks under that spread is the guide's way to spare yearlings. The guide prints no sample for the inch marks and limits them to the Southeast. No test of a 13-inch rule outside the Southeast appears in these sources.

STEP 3 · Season window

Middle-age bucks read older in fall photos and younger in winter photos

University of Missouri Extension shows one buck in good flesh before the rut and worn down after breeding. The neck swells while the rut is on. The Mississippi State guide says an older buck may then lose as much as 25 percent in body weight from more movement and less food. One winter frame alone can make a mature buck look young.

The authors fit one model on pre-breeding pictures and another model on post-breeding pictures. Our read is to grade a photo only against other photos from that same season. In the enclosure test a September or October picture moved bucks of 3.5 years and bucks of 4.5 years toward the 5.5 class. A January or February picture moved those ages toward the 2.5 class and the 3.5 class. Four of the five class percentages were higher after breeding than before it. Only the 2.5 class dropped from 86 percent to 71 percent. A September picture set beside a January picture of one buck does not settle his age.

STEP 4 · Camp rule

Pass 1.5s and 2.5s and skip the split between 3.5 and 4.5

Our antler-point guide records the plain age rule from Mississippi extension. Pass every buck that is 1.5 years old and every buck that is 2.5 years old. You can apply that rule only when those ages show on the live deer. The 1.5 and 2.5 classes were far more often right than the 4.5 class. Saving bucks until 4.5 or older leans on the age the ratios missed. To put older bucks on the ground, pass the yearling with the doe frame. Pass the lanky 2.5-year-old while the legs look long for the chest. Stop grading 3.5 against 4.5 when you decide to shoot.

A tooth age still leaves the camera label only partly checked. Our known-age jaw guide shows why a tooth age for an adult is a range and why one harvest-report year follows the method behind it. For each buck picture this season use just three words, yearling or older or not sure. If you later kill one of those camera bucks, place your word beside the age a jaw exam or a lab returns. Matched pairs gathered on ground you hunt are the strongest test you can give your own eye.