Karl Miller doesn’t hesitate when asked to list the five key factors of antler growth in white-tailed deer.
“Nutrition, nutrition, nutrition, nutrition; and then age and genetics, but you can’t do anything about genetics,” said Miller, professor emeritus at the University of Georgia’s Warnell School of Forestry and Natural Resources. “Good health—physically and socially—also matters, but that’s a big function of nutrition. Healthy bucks best express their potential. Antlers are a luxury item. A buck has to take care of all its other biological needs before diverting much for growing antlers.”
Deer that consistently meet their bodies’ nutritional needs typically live in fertile agricultural areas that dependably produce good crops and natural browse, thanks to rich soils and consistent moisture. “Good dirt grows good food,” Miller said. “If the soil is conducive to agriculture, it’s conducive to growing antlers. All you need is consistent rainfall for everything to grow, including antlers.”
April Showers Jim Heffelfinger, a researcher at the University of Arizona, and wildlife science coordinator for the Arizona Game and Fish Department, said antler quality fluctuates annually with the weather in arid regions.
“April showers bring big antlers,” Heffelfinger said. “Rain means everything to antlers from South Texas and across the Southwest. Deer need that flush of fresh forbs and flowers for good health and maximum antler growth. You won’t get that after a dry spring or during prolonged drought. Without good rainfall, good nutrition won’t be available across many wild landscapes.”
Mickey Hellickson, a biologist with Orion Wildlife Management Services in Corpus Christi, Texas, said that rainfall is critical in South Texas from March through May and plays a huge role in antlers for bucks 5½ years and older. When Hellickson was chief biologist at the King Ranch for 12 years, he found that rain explained 85% of the variation in the number of bucks harvested each fall with antlers gross-scoring over 160 inches.
Rain alone isn’t enough, however. Some regions can get adequate rainfall, but produce bucks with middling antlers if acorn production is poor. “Deer herds in the southern Appalachians run off of a mast-dependent economy,” Miller said. “They have few nutritional alternatives during years of poor mast production. You’ll see bucks benefit the year after a strong acorn crop, so regions subject to annual fluctuations—whether it’s mast, rainfall, or both—just don’t produce as many Boone and Crockett bucks over time.”
Bank on Habitat Brian Murphy, staff biologist for HuntStand and former CEO of the Quality Deer Management Association, said nothing can compensate for long, dry conditions, even sustained supplemental feeding programs.
“Private ranches in Texas and Oklahoma that provide deer chow year-round documented 15-inch increases in average antler growth and 15-pound increases in average body weight, but that’s a lot of time, effort, and expense to take on,” Murphy said. “And it only works with adequate rain. If you’re in a prolonged drought, you can’t feed your way out of it. In most cases, you can’t build management programs on artificial feeding.”
Murphy said landowners and property managers will see more consistent results by improving native habitats, and maintaining crops or food plots on 3% to 10% of their land.
“When you provide sustained nutrition and good cover, and you have another 10% of your woodlands in early-successional habitats, you’re well on your way,” Murphy said. “Some people also like to provide mineral supplements in hopes of growing bigger antlers, but there’s a near absence of science behind that. If you want to try mineral supplements anyway, it’s icing on the cake, but it won’t make up for drought or poor overall nutrition. I’d also only consider it for areas without chronic wasting disease. It’s never good to concentrate deer artificially, which increases the possibility of disease spread.”
Selective Harvest Hunters can also affect the herd’s size as well as its sex and age structure each time they press the trigger or release. No matter how fertile the soil and bountiful the rain, no yearling buck will grow trophy antlers, and few 2½-year-olds will set records.
“Hunters have to decide if they have the time and patience to let young, average bucks reach maturity,” Murphy said. “Are you happy with 2½- to 3½-year-old bucks, or are you happy only with 150-class bucks and bigger? You need to set realistic expectations for where you hunt. Most bucks reach about 75% of their antler potential by age 3½ and 90% of their potential by 4½. Bucks in those age classes fit the bill for most hunters.”
Bucks usually achieve peak antler production by age 5½ to 6½, and then level off at that size until age 9 to 10. “A buck that’s 6½ isn’t old. It’s still at its peak, physically,” said John Ozoga, a biologist who studied whitetails for 30 years at the Michigan Department of Natural Resources’ Cusino Wildlife Research Station in the Upper Peninsula. “A buck doesn’t start losing it until it’s about age 10. Few bucks make it that long, but that’s when their antlers and body decline, along with their health.”
Even though age and nutrition can prove challenging to improve in wild deer, at least they’re understood and subject to management. In contrast, antler genetics are not. All attempts to “improve” a herd’s antler genetics prove futile in the wild, whether by culling “inferior” bucks or importing “superior” blood lines from different regions.
Donnie Draeger, a biologist at the Comanche Ranch in Texas, worked with Texas A&M University on a large-scale culling experiment from 2006 to 2019. Draeger’s teams captured 2,937 bucks, some more than once; and “sacrificed” 1,333 that didn’t have at least six points as 1-year-olds, or eight points when 2 or older.
After analyzing data from 14 years of intensive culling to weed “inferior” bucks from the herd’s gene pool, Draeger conceded failure. The herd’s antler traits didn’t change. “It didn’t do any good,” he said. “The average score of the bucks did not improve. That shocked me as a hunter and guide. I thought we were making a difference. My gut said we were having an impact. Well, empirical evidence doesn’t lie, but my gut apparently does.”
Conclusion That’s why wildlife biologists agree that nutrition remains the dominant factor in antler growth. Then again, managers have known that for 800 years. As William Twiti, an English gamekeeper and huntsman, wrote in “The Art of Hunting” in 1327: “The head grows according to pasture; good or otherwise.”
Feature image via Matt Hansen.
