Buckmasters Magazine

The Gene Factor

The Gene Factor

By David Hart

Can hunters use selective harvest to improve buck antlers?

Imagine being able to take inferior bucks out of the population so only the biggest, strongest and healthiest are left to pass on their genes. The results of your genetic selections would create a land filled with giant bucks with racks so massive, you’d end up on the cover of Buckmasters when you had the good fortune of tagging one.

You don’t have to imagine. It not only can be done, deer genetics are being altered throughout the country on a regular basis, producing bucks with antlers so big they almost tip over from all the weight on their heads.

There’s just one problem: It’s all taking place on deer farms, where animals with only the best qualities are chosen to breed. They are given the highest-quality nutrition, and they live a sedentary life free from predation and other risks. Some bucks actually grow massive antlers as yearlings, something that can never be accomplished in the wild.

The only way you’ll see one of those bucks during hunting season is if you pay a hefty fee to walk into an enclosure with a rifle in your hands. Many of the bucks bred in captivity are sent directly to preserves and high-fence operations.

Ethics aside, the notion of creating a genetically superior deer herd through selective harvest sounds ideal. Who wouldn’t want to increase the trophy potential on their land?

It sounds easy. Shoot the scrub bucks, let the young bucks with good genes walk and see the results in just a few seasons.

THE BIG PICTURE

If only it was that simple. There’s no question it can be done in a controlled environment such as a deer farm, but free-range deer? The truth is, it is all but impossible to alter the genetics of a local deer herd, and it’s even more difficult to alter them on a larger scale.

“There are so many different factors at work,” says Mississippi State University professor of wildlife ecology Dr. Steve Demaris. “Everything from the environment to hunter harvest influences antler size. Genetics is just one part of the equation, and it’s the one part we have virtually no control over.”

One ongoing study conducted on a 118,000-acre Texas ranch aims to find out if the genetics can be improved by selective removal of specific bucks. Researchers with the Caesar Kleberg Wildlife Research Institute in Kingsville, Texas, are using three study areas, including a control area in which no bucks are being removed from the population. In one, yearlings with less than 6 points, 2-year-olds with less than 8 points, 3- and 4-year-olds with 8 points or less, and 5-year-olds and older with antlers measuring less than 145 inches are culled. The third area includes culling the same older bucks, but those under 3 are released.

They have captured and recaptured hundreds of bucks so far. The project has been under way for seven years, but researcher Dr. Robert DeYoung says there does not seem to be any improvement in antler size.

“We removed a high number of bucks, and that skewed the buck-doe ratio, which spread out the rut and the fawning period,” he says. “A number of fawns were born later in the year and had smaller antlers as a result. We are now going through a period where we are not culling deer.”

He was involved in a similar study that lasted seven years on the King Ranch. It also showed no tangible benefits from selective harvest of cull bucks.

Even if culling did work, the typical hunter might not be able to identify a buck that meets a certain criteria.

DeYoung, who has aged thousands of deer by examining their teeth, says 22% of the bucks they culled should not have been culled, and a high number that did not get removed from the population should have been.

We were wrong in aging deer on many occasions,” he said. “If we were wrong on that many deer, I suspect a lot of hunters would take out the wrong deer, too.”

Other culling programs are undertaken by experienced guides who not only look at countless bucks, they also see the same bucks on a regular basis. Most hunters might only see a buck once or twice in a typical season before it gets shot by a neighboring hunter.

WHAT ABOUT SPIKES?

Spikes, however, are virtually always yearlings. Those spikes are a prime target for some hunters who insist they will not only dilute the gene pool, they will likely never grow trophy-class antlers.

The problem with shooting spikes on sight is that a spike on your property today might not be on your property tomorrow. Yearling bucks have a built-in mechanism that prompts them to leave their birth place. Known as dispersal, some travel a mile, but many others establish a home range 5, 10 or even 20 miles from their birth place. It’s a natural process that helps promote genetic diversity in the species.

Demaris says bucks with good genes will leave your area while bucks with poor genes will migrate in. That automatically complicates any effort to improve a deer herd’s genetics.

“You can’t control what comes and goes in a free-range deer herd,” DeYoung said. “That’s what happened during the King Ranch study.”

Spikes aren’t necessarily inferior, either. Various studies have shown that a spike today could be a quality buck in the future, although other studies have shown that spike yearlings tend to have smaller antlers on average later in life than branch-antlered yearlings.

THE OTHER HALF

Another vital factor is our inability to determine the genetic quality of antlerless deer. Bucks are only half the equation. Females contribute half the genetic make-up of a fawn. Can you look at a doe and tell if she has good genes? Of course not.

A healthy doe is more than a product of her genetics; she is also a product of her environment. Habitat quality, deer density and forage quality all play a role in her general health and outward appearance. A skinny doe might not be genetically inferior. She might just be unhealthy.

That’s true for bucks, too. DeYoung says wild bucks that have poor-quality forage will never reach their full potential, no matter how good their genes are. Pen-raised deer, on the other hand, are fed a carefully regulated diet that maximizes antler growth.

INTRODUCED GENETICS

This raises the question, what about releasing pen-raised, genetically-superior bucks so they can pass their giant-antler genes on to wild whitetails? A group of Alabama sportsmen tried that when they released about 20 pen-raised deer in Marengo County in 2012 before legislators outlawed the practice. Their theory was that each buck would pass on his genes to the next generation, and that generation would pass on their genes and so on.

Those involved claimed that in just five years, two released bucks would produce more than 2,400 shooter bucks.

The intentions were certainly good, but it was destined to fail before it got off the ground. Numerous studies have examined the impact of released deer. None of them showed positive results. One study in Texas found pen-raised deer had an abnormally high mortality rate. Eight of 13 bucks released were dead within a year. Another study found that just 17% of released fawns survived to maturity.

More important, there’s no guarantee pen-raised bucks would actually breed many wild does. Demaris says wild bucks would likely sire does in estrous before farm-raised bucks had the opportunity.

“There are too many other bucks in the wild population. One buck has a small impact on the population,” he said.

In response to the Alabama group’s efforts, Demaris used a computer model to look at the potential impact of releasing pen-raised deer. He found the group’s plan would have improved the overall antler size, but only when a large%age of the wild population was replaced by genetically-superior pen-raised deer. Average antler scores in the simulation increased by 12 inches when 25% (or 500) of a wild population of 2,000 animals was replaced.

Scores improved by less than an inch when just 5% (100 deer) of the population consisted of pen-raised deer. If that’s not convincing enough, Demaris figured it would take 20 years to reach those results.

“The cost for each unit increase in score was $115,000 in a free-ranging population,” he said. “We’re talking a lot of money to make any noticeable difference, assuming the best-case scenario.” (Costs were based on the cost of pen-raised deer.)

THE BOTTOM LINE

Science has shown it’s virtually impossible to create a herd of perfect bucks with perfect racks through normal hunting. No matter how carefully we choose the bucks to shoot, it will have no noticeable impact on the genetic make-up of the deer on your land. However, DeYoung and Demaris agree that selective harvest can help.

“Taking out below-average deer leaves more resources for the better bucks,” Demaris said. “That won’t necessarily alter the genetics, but it can improve the overall health of the remaining deer through more available forage.”

The problem, both researchers agree, is few hunters can quickly identify a below-average buck. Just as DeYoung made mistakes aging deer, few hunters can accurately age a buck on the hoof. That below-average buck you just shot might have had good potential.

The good news is we can control some factors. Most notably, hunters can use what biologists call trigger management – don’t shoot small bucks if your end goal is to see more mature animals with larger antlers.

There’s no guarantee he’ll survive when he crosses onto the neighbor’s land, but if you shoot him, you can be certain he will never reach his full potential, no matter what his genetic makeup.

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This article was published in the October 2015 edition of Buckmasters Whitetail Magazine. Subscribe today to have Buckmasters delivered to your home.

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