Got questions? Ask us.
The Tale of a QDM Club by Dave Edwards
Own Your Own by Virgil Peritts
What Is TSI? by Matt Ross, QDMA
Native vs. Non-Native by Gabriel Karns, M. Colter Chitwood, Chris Moorman, and Dr. Chris DePerno
Oaks For Bucks by Chris Moorman
Deer Season: A Time For Kids by Stephanie Mallory
The Need For Minerals by Brian Murphy, QDMA
Perlitz Ranch Hosts Youth Camp by Kelly Haydel
Timing the Rut With Fawns by Gabriel Karns, M. Colter Chitwood
Ecological Reasons For Hunting by Dr. R. Larry Marchinton and Dr. Karl V. Miller
What percentage of a buck's antler development potential comes from the doe's genes? by Realtree Whitetail Team
Where were the bucks? by Team Realtree
Growths on Deer? by Team Realtree
How Many Teats? by Team Realtree
Why No Oaks? by Team Realtree
Special thanks to:
Quality Deer
Management Association
Whitetail Insider
To Cull or Not to Cull?
First, here’s some background.
Antler size is affected by age, nutrition, and genetics – in that order of importance. So, the first step to producing quality bucks in most areas is to let them live 4-5 years before they are harvested. This simple step can yield remarkable results -- if hunters pass on younger bucks and are willing to wait several years to see results.
Nutritional quality and quantity of browse affect antler size. Although both can be improved with habitat management, soil fertility is a fundamental prerequisite. The best deer come from regions of the country with the best soil fertility, like the deep prairie soils in the Midwest.
Genetics is a distant third. Let’s go back to the original question: To cull or not?
The underlying rationale to justify culling is that antler size is heritable, and through selection, inferior bucks can be weeded out, leaving only the best. But is there scientific data to support this?
Recently researchers from Texas Parks and Wildlife addressed the question with penned deer where they could control buck and doe breeding and then follow their offspring over an 8-year period. They collected data on antler size from 41 breeding herds consisting of one buck and about a dozen does. To cull out inferior antlered bucks, each year they allowed only 5-6 of the best yearlings to be sires in the next breeding season. Because does also contribute half of the genes to their buck offspring, researchers also removed does that tended to produce spike offspring.
What were the results? Over eight years, the percentage of spike antlered yearlings declined from 33% to 3%; whereas, yearlings with eight points or more increased from 3% to 48%. Number of points, inside spread, main bean length, basal circumference, and mean Boone and Crockett score all increased. Early or late fawn births had no effect. Thus, it is apparent that, under carefully controlled conditions, antler quality can be improved through selective breeding.
Can these findings be applied to widespread deer management? We don’t think so for three reasons.
First, culling spikes is not a panacea -- the entire herd and habitat must be managed. Because better habitat means a better opportunity for deer to reach their genetic potential, habitat must be managed to enhance quality. Does must be harvested to keep the herd well below carrying capacity so that competition for food is reduced.
Second, remember that does contribute half the genes to their buck fawns. We don’t know any way to cull “inferior” does, as was done in the penned study. Attempting to select for superior bucks with no means to select for “superior” does, is like wrestling with one arm tied behind your back.
Third, timing of the rut needs to be considered. If spikes are culled after the rut, then they would have already bred and passed on their genes. It’s a myth that only mature bucks do all the breeding. Genetic studies have shown that even in populations with a large proportion of mature bucks, yearlings still do much of the breeding. To have any potential effect at all, spikes would have to be culled before the rut. If the hunting season begins after the rut, then culling spikes makes no sense at all.
Then what is an effective way to develop quality bucks? First and foremost -- let bucks get older before they are harvested. Studies have shown that spikes can develop large racks. Check out the trail camera photos below that were provided by Dr. Harry Jacobson. The “inferior” spike #33 developed massive antlers at three years and beyond.
One final point -- antler quality of an individual may vary annually. For example, a buck might injure or break its antlers during antler growth and have inferior antlers that year. Other factors such as disease or injury could result in one year of inferior antlers. With a strict culling policy, you might remove a buck with excellent potential for large antlers. Note the deformed left antler in the middle picture in the bottom row of buck #33. An apparent antler injury caused this deformity. However, the following year, there is no evidence of the injury. One way to avoid these kinds of mistakes is to use trail cameras and learn to identify as many individual bucks on your property as possible.
To limit harvest to older bucks, hunters must have a criterion that restricts harvest of young bucks. At Chesapeake Farms an antler-spread criterion, where only bucks with antlers beyond their ears can be harvested, effectively protects all yearlings. Appropriate spread criteria to protect yearlings in other geographic areas would have to be established. Deer biologists who work for state agencies can be very helpful when developing these criteria.
Point restrictions are not as effective and can result in high-grading. For example, establishing a 6-point restriction, might remove exceptional yearlings that should be allowed to get older and turn into real trophies.
 |
 |
 |
 |
 |
 |
Another scientific study supports our recommendation to let spikes walk. Researchers from Stephen F. Austin State University examined the relationship between antler sizes as juveniles to subsequent antler sizes as adults. In contrast to the penned study above, the SFASU study involved free-ranging deer. They found no relationship between antlers as a yearling and antlers as an adult. To quote the authors: “By 4.5 years of age there were no differences … in antler measurements regardless of the amount of development of the first set of antlers at 1.5 years. We concluded culling of yearling males based on number of antler points would have little positive effect on overall antler quality in future years.”
What do we recommend? Don’t shoot spikes. Establish an antler restriction criterion that is appropriate for your habitat quality and protects all yearlings. Then, wait 3-4 years for a wall-hanger.
About the authors: Richard A. Lancia is a Professor of Wildlife Science at North Carolina State University. Mark C. Conner is the Manager of Chesapeake Farms.