Despite the fact today’s hunters pursue some of the highest densities of mature bucks in history, big whitetail bucks are still an uncommon sight. Specimens of male deer with above-average antlers are not the norm, which is just one part of what makes them so darn special. Therefore, most hunters want to know the precise ingredients in that big buck recipe so they can duplicate it and experience the fleeting magic of impressive antlers more often.
The truth is that the main driver of antler growth is a complex combination of age, nutrition, and genetics. But, of those three, which is the most influential? And which one do we have the most control over? In this article I break down the influences of buck age, nutrition and genetics – and the relative importance of each – in plain talk. This is vital information for every hunter, especially if the standing crop of big bucks where you hunt is smaller than the ones you dream about.
The Age Factor
White-tailed deer grow and shed a new set of antlers each year starting at age 1½. With each successive year their antlers usually grow larger than the last – up to a point. The graph below shows the ability to predict the average percentage of maximum gross Boone & Crockett score achieved over the life of a buck by age class.
As you can see, most bucks make the biggest leap from 1½ to 2½ years of age – nearly doubling in antler size – and plateau somewhere between 5½ to 7½. This predictability only really works up until a buck is 5½ years old, after that it’s a coin toss if a particular deer will grow bigger or shrink.
So, an obvious way to increase antler characteristics in an area is to protect young bucks and allow them to grow older. Alternatively, a sure-fire way to limit antler potential is to repeatedly kill the majority of bucks before they’ve reached maturity, especially those that have above-average antlers at younger ages. This latter point is equally as obvious but not stated as often!
If most hunters on the landscape abide by the same guidelines, age is a very predictable variable to manipulate in a deer management program to observe a change in antlers. However, don’t assume that simply not shooting young bucks will make a difference in a short period of time, or that every mature buck will have trophy-sized antlers. Like I stated before, it’s a complex relationship and there are lots of direct and indirect influences that need to be accounted for (more on that later) – including the influences from nutrition and genetics.
The good news is that if you want to increase the average antler size of bucks in your area, then considering buck age is the simplest, cheapest, and most efficient way to do so. If you need more practice, NDA offers “Age This” examples in every issue of our weekly newsletter. Also, setting individual age-based harvest goals can vary for every hunter and can change over time, by location, experience level or with new priorities.
Year-Round Nutrition
Deer eat a substantial diet, and when they consume more calories than they need, guess what happens? They gain weight, just like us. Those excess nutrients and minerals go to all physiological functions beyond maintenance, including antler growth. Big antlers certain have a purpose, but they aren’t needed for survival.
A lot of research has focused on deer nutrition. But the key point you need to know is that antler development is greatly affected by a buck’s diet all year long, not just when the antlers are growing. In fact, the influence of nutrition extends back to when the buck was born and even as far as a generation or two to the nutritional plane of the buck’s grandmother!
That is why the NDA continues to educate our members about habitat management, because when those practices are applied, hunters can directly influence the amount and types of vegetation available for deer to eat. We also promote doe harvest, through which you can balance a deer population with its habitat, increasing nutrition for all deer.
Moreover, you can apply these techniques anywhere in the whitetail’s range. It doesn’t matter where you live or hunt, the soil quality, or even if you purposely plant something for deer, like a food plot, or simply manage the native plants since certain types already provide deer what they need.
Although nutrition has such a positive impact on antler size, we believe it ranks second to managing for age because it takes more time and effort to significantly increase nutrition than it does to start protecting young bucks. In addition, the gains in antler production seen at the population level due to elevating nutrition, for example the inches of average Boone & Crockett score, will likely be less in the short term than what can be realized from advancing the average age of bucks walking around during the season.
About Genetics
The influence of genetics is by far the most talked about of the three factors discussed in this article. Fortunately, it also has been carefully studied. So then, we must have an iron-clad understanding of its influence, and most hunters agree with those findings, right? Unfortunately, that statement is only partly correct. How can that be?
It’s easy for me to see how much influence DNA has on the physical characteristics of one’s offspring every time I look at my daughters or my parents. I know you share the same feelings when considering your own family tree. That common experience is the primary reason why many hunters believe a deer’s genetics plays the biggest role in determining antler size. It’s also one of the most rampant myths in deer management perpetuated in popular writing and social media.
While it’s true that an individual buck inherits certain traits from its own lineage, the science shows that genetics has the weakest effect on antler size compared to nutrition and age when managing wild deer populations. It turns out that specific antler characteristics, like antler spread, number of points or tine/beam length, are not very heritable. In fact, a buck’s gross antler score is only 35% heritable. That means there’s only about a 1 in 3 chance a big buck will have a son with big antlers. But even if antler traits were heritable, we unequivocally can’t manage genetics in free-ranging deer herds.
Therefore, don’t be fooled into thinking that you can improve antler sizes on your hunting land by killing “cowhorn spikes” or all the lop-sided bucks or whatever else is being espoused online. Selective harvest in the wild simply does not change deer genetics, for better or worse, no matter how hard you try.
Other Influences
Part of the complexity to all of this comes from understanding and admitting that numerous other factors may impact antler production besides age, nutrition and genetics. Let’s face it, there are a lot of odd antlers out there, and in many cases it can be pretty hard to determine why a particular set of antlers grow the way they do!
Abnormal antlers can be stunted, asymmetrical, or missing some element that would otherwise make it normal. There are plenty of direct sources of abnormality that have nothing to do with the three factors discussed above, such as an injury to the velvet antler while it’s growing, injury to the pedicle, or even trauma to the body. Then, there are also indirect causes of misshapen antlers such as sickness from a bacterial infection or disease, parasites and even weather. And, sometimes, people even mistake a broken antler as something they can fix by killing the deer carrying incomplete headgear.
These other influences are not something you can manage, but it’s good to know they exist.
Summary
Genetics are like a blueprint for what a buck’s antlers could be, providing a design for their potential size, shape, number of points and overall conformation – as long as everything goes according to plan. However, his age is the primary factor that allows that design to be fully expressed, and nutrition provides the building blocks for that expression. Without consistent, optimal nutrition, a deer – regardless of its genetic potential – may never reach its maximum antler size. Similarly, even with good genes and nutrition, a young buck simply hasn’t lived long enough to grow its largest antlers.
So, if little boys are made of snips, snails and puppy-dogs’ tails, then where in the world do big bucks come from? If you want to see more large antlered bucks, focus on age first, then nutrition. And I mean year-round nutrition, not just food that you can hunt over during fall and winter. Genetics is out of your control in wild herds, so just don’t worry about it.