Peak Antler Development in Whitetail Bucks: When?

It’s never too early in the year to start talking about bucks and antler growth for the upcoming hunting season. I have high expectations for some older bucks that should look very nice this fall, especially given the timely late-Spring rains that just soaked the area. That translates directly into additional high-protein forbs, new growth on browse plants and increased antler growth, not to mention better habitat conditions for hiding fawns. Things are looking up!

Today, we’re discussing antlers. We can still refer to them as “horns” while at deer camp.

Specifically, we’re looking at changes in antler growth in bucks, mature bucks. Every deer hunter has stories or at least game camera photos of some odd-antlered deer. And let’s face it, hunters enjoy talking about those deer as well as all the other wild things we’ve witnessed while out hunting white-tailed deer. There are an untold number of events that happen in nature that we never had seen had we not been sitting nearly motionless and scentless for hours on end. Ok, let’s focus.

When Does Antler Growth and Development Peak in Bucks?

When it comes to managing deer it’s really all about population (herd) management on a given property, although certain individuals (bucks) can be exceptionally poor or amazingly great. It’s also the outliers that we tend to remember, the ones way out on either end of the bell curve. Some recent and extensive research on antler development using known-aged bucks seemed to confirm some of the things we knew about whitetail bucks and antlers, but they also found some other interesting data about changes in marked, free-ranging bucks from year to year.

Mature Bucks and Changes in Antler Size

The general consensus among seasoned hunters, deer biologist and academic research suggest that most white-tailed bucks reach peak antler growth around 5 to 6 1/2 years of age. This is definitely the case for the overwhelming majority of bucks, so it definitely has management implications. That said, a few do some really whacky stuff:

Source: “Using data from 170 bucks captured more than once while they were mature, I constructed a distribution of the magnitude of change in antler size for bucks 5 to 8 years of age. The figure below shows the distribution of 211 instances in which antler-size change was measured in subsequent years.

For example, there were 47 bucks that gained 0-5 inches in antler size from one age to the next and there were 37 bucks that lost -5 to -0.1 inches. These data come from the South Texas Buck Capture project with captured bucks on 5 ranches in Webb and Kleberg Counties over a 10-year period.”

Changes in Mature Buck Antler Growth

“From these data, it is clear that successive antler sets of individual mature deer vary by less than 20 inches in 90% of the instances. However, in 3% of instances, antler size changed by more than 40 inches. We will use 40 inches as our criterion to define an outlier in antler-size change of mature bucks.”

More on Antler Growth in Deer

Male white-tailed deer grow and shed antlers on an annual basis, typically starting a new set in late spring. Antler growth is regulated by hormones, which are controlled by day length (photoperiod). Throughout late spring and summer, antlers are filled with a rich blood supply and are covered with a hair-like membrane referred to as velvet. During this stage, antlers are quite vulnerable to injury, which many times result in deformed antlers.

Actively-growing antlers are high in water and low in dry matter content (phosphorus and calcium). Late in the summer, antler development slows and the antlers begin to mineralize (harden). When growth is finally complete, blood flow to the antlers stops completely and soon after all of the velvet is rubbed off (typically within a single day). Hunters often see a by-product of this effort, as rubs will be found on pliable saplings up to small trees that are 7-8 inches in diameter. This result is a buck with a brand-new set of hardened antlers.

Following the whitetail breeding season, de-mineralization occurs at the base of the antlers in healthy bucks and that causes them to shed their antlers. Early antler shedding can be attributed to deer that are not completely healthy, for whatever reason. Immediately following antler drop the entire development process starts over.

Increase Antler Growth in Bucks

Increase Antler Size

Most hunters and property owners involved in deer management are interested in healthy herds and increased antler growth and size in bucks. There are numerous other positives that result from managed whitetail populations, the most important of which are healthier, more diverse plant communities for all wildlife species.

Good habitat equates to better bucks, but sometimes additional inputs are needed to harness all of the antler-growing potential within bucks found on the property. It’s often during the deer hunting season that hunters take inventory of the bucks roaming their land, but the time to take action for next year is right now.

How can We Increase Antler Growth in Bucks?

Recipe for Big Bucks?

Question from Mike P.: “I am involved in a small self-management plan on a 90 acre farm in Pennsylvania. Our deer are free ranging and are very low pressured. We do a buffet of food plots, about 7 acres of turnips, radishes, oats and clovers. We are also involved in the creeps program. We have established a great heard and do not harvest bucks until they have reached 130 class. What we seem to be lacking is antler mass.

We have been told by local deer farmers to add protein to their diet. We were thinking of mixing roasted soybeans with corn for our winter feeders. We have also been told to be very careful on the ratio of the mix and could make the deer “sick.” My question is, what is true and what is false, what’s right and what’s wrong? Is there something else we can do to add antler mass?”

Best Ways to Increase Antler Size

First, this is a great question to ask since most of the deer hunting seasons have wrapped up for this winter and because another antler growing cycle is about to start. Additionally, there are likely many other hunters around the US that are also wondering how to increase antler growth in bucks. The months following the rut are critically important for future antler growth because bucks are attempting to fully recover from the intense, grueling breeding season.

Antler size can be improved on bucks through adding points, increasing the lengths of points or by increasing the circumference of existing antler material, thus increasing mass. A lot of hunters look for a buck with a wide-spreading rack, but I’ll take the heavy-horned freak nasty every time. The only way to produce and harvest larger bucks is to add inches to antler measurements. Points (and plenty of them) tack on the most in terms of a buck’s score, but there are several other measurements, as well as factors, that play a role.

A How to on Improving Antler Growth in Deer

Antler Growth in Bucks

Antler growth in whitetail bucks always comes down to three things: age, genetics and nutrition. Antlers get larger as a buck gets older up to a certain point, then they start declining in size. There is some debate on when exactly that occurs, but I don’t think there is a single right answer here. Just as individual bucks vary in antler quality, I think different bucks peak at different years. Environmental conditions, buck to doe ratios and other factors all impact this. Hunters may see a buck’s best antlers anywhere from 5 1/2 to 8 1/2 years of age. Antler mass will increase with age.

Genetics are obviously important, but they are difficult to manage and this is especially true on small acreages where whitetail management and growing better bucks is the goal. Genetics for antler growth comes down to WYSIWYG — -what you see is what you get. That is, unless you do something different. In the situation outlined above, it’s nearly impossible to make meaningful genetic changes in the deer herd. The size of the property may be a limitation, but the road does not end there.

Landowners and hunters have much more control when it comes to deer nutrition. In fact, there are many options when it comes to providing additional, high quality foods for whitetail. Food plots can work great in areas with dependable rainfall and good soils. In other areas, not so much. But this opens the door to supplements such as protein pellets, whole cottonseed and roasted soybeans. And let’s not forget that superior, natural forb and browse production can be encouraged on any property through deer habitat improvement that involves a variety of land management practices.

Deer Herd and Antler Growth

Ideally, hunters will shoot bigger bucks if they simply provide the genetically-best bucks on their property with optimal nutrition until they reach 5-8 years of age. As I mentioned, this would be ideal. The reality in this case is a 90 acre property that currently has bucks that are lacking antler mass. Without knowing any more about the situation that what was given, there are several things that could be in play. Any or all of these factors could be impacting the free-ranging bucks found on the property and in the area.

First, there is always the chance that you’re just unlucky, that the deer in your area do not have the genes to grow heavy horns. It’s unlikely, but completely possible. Antler mass, as it turns out, is one of the most heritable traits in deer antlers. Of all the traits that a buck may get from his father for antler growth, mass is most likely to stick. So, the WYSIWYG principle applies here. Thin-horned bucks sire more thin-horned bucks. But, in your case, are their genetics to blame?

An often overlooked factor that can seriously impact antler size in bucks is the buck to doe ratio of the deer herd. I mentioned at the top of the article that this was a timely question because bucks are currently still recovering from the rut. If bucks are physically run-down following the rut and do not fully recover, then they will remain so and will start the upcoming antler growing season at a huge disadvantage.

Managing Deer for Increased Antler Size

If there are 4-5 does per buck in your area then this could be an issue. If there are 6-7 does per buck in the area then this is a problem that should be addressed. The ideal buck to doe ratio in this situation would be 1 buck for every 2-3 does, but the ratio could be much closer to even on very large acreages (or high fenced properties) with more control over deer harvest.

In this situation, there is no doubt that nutrition could be an issue contributing to poor antler mass. In fact, it probably is. Furthermore, poor nutrition would only make the skewed buck to doe ratio example described in the paragraph above even worse for bucks.

Poor nutrition is a result of too many deer for the habitat, or in other words, not enough food for the deer herd. Keep in mind that just because there may not be an abundance of deer does not mean there aren’t too many for the habitat. It all boils down to the number of available pounds of deer food per mouth per day. Of course, an insufficient diet may not necessarily be of a caloric nature, but one related to the availability of minerals. Mineral deficiency is most common on sandy soils or in areas that receive high amounts of precipitation. If this sounds like you, listen up.

A How To on Growing Bigger Bucks

Options for Increasing Antler Size

A buck’s hardened antlers are made up of approximately one-half protein and one-half minerals. If bucks are reaching maturity and still have weak mass measurements, then the deer management strategies on your property should focus on increasing the availability of these potentially limiting factors. The objectives should be to provide more protein, minerals (phosphorus and calcium) and trace minerals for all deer. Here are few ways to get the job done:

  1. Food plots – Get a soil test for your plot area and fertilize and lime as necessary. Leached soils are low on minerals and other nutrients. Make sure that the deer foraging on spring and winter food plots are getting more than they see, especially post-rut and into the spring.
  2. Protein Pellets – One of the best ways to supplement whitetail deer is through protein pellets with at least a 16 percent protein content. Many commercial brands are available and they contain not only protein, but all of the necessary macro- and micro-nutrients.
  3. Other Foods – Protein pellets are great, but they are not the only game in town. Whole cottonseed and roasted soybeans are extremely high in protein and may be easier to get your hands on in some areas. These foods lack all of the nutrients that whitetail will need, but this option could be combined with plot and/or mineral sites. Stay away from corn as a supplement. In high quantities corn can cause several problems for deer and it’s low in protein.
  4. Mineral Sites – These are debatable since there have been no direct links between mineral sites and larger-antlered bucks, but there is no doubt that whitetail are attracted to these salt and mineral mixes. Research in livestock have found that minerals improve digestion, increase weight gains. Heavier deer tend to have heavier antlers.
  5. Fertilize – This practice is not limited to just food plots. Native browse species also benefit from nitrogen, phosphorus and potassium. Deer will readily consume preferred trees, shrubs and vines that have been fertilized. They can taste the difference. You’ll see the difference.

Deer Hunting, Management and Rattling

White-tailed deer hunting seasons are already going full bore in many states with good bucks already on the ground, but hunting is just beginning to heat up down at southern latitudes. Two things come to mind with the early part of the season upon us: rattling for buck hunting and selective harvest for the purpose of deer management. Both can take place on properties looking to ultimately improve antler quality in bucks, and these two tasks are not necessarily exclusive of one another. Managing a deer herd not only means shooting deer, but removing the right deer and at the right time.

The removal of unwanted bucks prior to the breeding season ensures that those animals do not participate; they no longer have the opportunity to pass on their genes. Earlier is always better when it comes to removing cull bucks. These management bucks, as many hunters so eloquently refer to them, often consist of middle-aged deer that show less promise than the remainder of their cohort (age class). Rattling while in the field prior to the rut ensures an active and hopefully exciting hunt, but also allows landowners and hunters the chance to fulfill management objectives.

Deer Hunting and Management - Rattling for Deer

Best Time to Rattle for Bucks

My experience has lead me to believe that rattling “horns” for deer is most effect earlier in the hunting season rather than later in the year. This may be contrary to what others have witnessed, but I don’t speak for them. My money is on the pre-rut period when it comes to rattling. Hunters can start rattling two to three weeks before the rut typically occurs in an area and have success. Days that have low, but sustained, wind speeds are ideal. Although I prefer to hit horns in the mornings, any time of the day will work.

Jeff M, Site Reader: “… for 2 consecutive seasons I have rattled in 2 shooters just as it was light enough to put my pin on them. One particular 5×5 came in hot looking in a 360 degree area for a fight or a competing alpha buck. Needless to say, his antlers are what I rattle with each season now. Last year, just as the sun was at the top of the lowest tree I rattled about 2 minutes and grunted a few nice tones and a 4×4 came in within 2 to 3 minutes. I wasn’t expecting him so soon, but he was delicious!

I have become paranoid about rattling with my decoy, thinking that once I’m settled in, they could be in range and rattling from a tree confuses them if watching my decoy. I now settle in, listen, and rattle if my buck bomb or decoy doesn’t bring some action first. I am a true believer in rattling. I know it works on the aggressive ones, even interested 1 to 3 year olds.

Use your senses of what deer may already be around before starting your cadence of rattling. Remember that sounds travel early in the AM if it’s still, and bucks will come from everywhere to see just what is up with a good rattling sequence. I start of lightly by tickling them together and then gradually move onto more heavy hitting at the end, followed by a few aggressive grunts.”

Don’t Wait for Deer Management

The management of deer herds varies from property to property. Objectives on one place will be different from another place down the road. Some want to shoot bucks found on their property at 4 1/2 years of age, some at 6 1/2 and so on and so on. There is no single management strategy that can be equated with success; there are many ways to get there, but it all depends on where you start. It’s kind of like all roads can lead to Rome, but your trip will different than mine.

One of the biggest problems that plagues many hunters interested in the management of whitetail deer is that they do not have clear-cut guidelines for buck harvest. What is the criteria on which bucks will be shot? When they are old enough? Only when they are spikes? When they are big enough? When they have missing brow tines? Managers must establish goals and guidelines and put them on paper before the shooting starts. As with everything in life, you’ve got to have a plan. Again, this plan will vary from place to place, but success in deer hunting is measured in a multitude of ways: age of buck harvest, bigger antler size, number of bucks harvested, and buck to doe ratio, for example.

An important thing to remember is that all bucks that you do not want participating in the rut should be removed as soon as possible. If this is done on an annual basis then improvement in the deer herd will be observed sooner rather than later.

Rattling and Hunting

One of the great things about deer hunting is that it can get exciting in a hurry when a big buck steps into the picture. This is especially true when it comes to rattling in bucks. Deer can often appear seemingly out of nowhere and have your heart just about pounding out of your chest. If you’re trying to manage a herd, then this is where a deer management program and a split-second deer hunting decision collide. The ability to age bucks on the hoof becomes increasingly important when time is of the essence, such as when a ornery buck is high-tailing it towards you and looking for a fight or maybe even a girl to steal.

At times like this, there is nothing better than having the skill to size up a deer in the field with regards to age, and maybe even antler score. If you are comfortable doing this then you won’t even think about it. It just takes practice. Also, if you run trail cameras leading up to the hunting season then there is a good chance you will recognize the deer, but there is also the chance that you rattle up something you’ve never seen before. That’s when it really gets exciting!

Just remember this when trying to rattle up a buck: start soft and slow and be patient. Sometimes deer will literally be just out of sight. Also, do not over rattle. On more than one occasion I’ve been “caught” by bucks while reaching for the rattling horns. If I’d waited just a few more minutes those deer would have worked their way in. A good rattling sequence is to rattle for 15 to 60 seconds every 20 minutes, increasing in both duration and intensity over time.

Deer Antlers as a Management Tool for Whitetail Bucks

The idea that the genetic composition of a deer herd can be improved through selective harvest is not a new one to white-tailed deer management, but it is a tough goal to achieve. This is especially true when dealing with free-ranging deer herds on small to mid-sized properties, which covers most of the land found within the whitetail’s range. Selective deer harvest, or “culling” if you’re talking deer out on the ranch, is not always an option for every hunter on every property. This management practice, however, should not be overlooked by land owners and hunters looking to improve the quality of deer herd found on their property.

The idea of culling deer is to remove bucks with inferior genes for antler growth and leave the genetically better bucks to do the breeding, thereby passing on those better genes to their offspring. It’s a simple concept and it works. Cattlemen figured this out a long time ago; put a really good bull in the pasture and you’ll have better calves. The thing that makes it difficult to implement with deer is that there are often many, many bulls.

Deer Management and Hunting: Using Antlers for Culling, Herd Improvement

Believe it or not, genes are not all that difficult to see in animals. Well, you can’t see the genes per se, but you can see how they are physically expressed. For example, it’s not all that difficult to find a good bull if you know what you’re looking for. The same can be said of a buck. Ranches can identify a good bull by age, so a deer manager should be able to identify a good buck by age. The difficult part is that all those deer are running loose on your property and you can’t get them sort themselves out by age and line up from most inferior to most superior while you’re out deer hunting.

If you are interested in learning more about using what’s on a buck’s head to manage the deer found on your property, then check out the webinar being offered later this week that features Dr. David Hewitt, Stuart Stedman Chair for White-tailed Deer Research at the Caesar Kleberg Wildlife Research Institute. There is no cost and you can watch from your home or office computer, just don’t let the boss catch you!

When: Thursday, September 19th, 2013, from noon to 1:00 pm CST

Topic: “Deer antlers as a Management Tool: The Role of Culling” Dr. Hewitt will be speaking on Deer antlers as a Management Tool: The Role of Culling. He will cover deer management objectives and the role of culling, reasons managers may wish to cull bucks, relationship between antler size at one age and antler size at a later age and the ability to change genetic potential for antler size in a free-ranging deer herd.

How to sign on: Simply point your browser to Texas Wildlife Association web site on the day of the webinar and click to join the Wildlife for Lunch webinar. By the way, WebEx webinars are not supported on handheld devices such as iPads or iPhones. Each web based seminar is fully interactive and allows you to engage the experts, make comments, and ask questions during the course of the presentation.

Determining Carrying Capacity for Deer Management

Question: “Hi, I’m not into deer hunting but I need to learn something about whitetail deer management. I live on an island in Puget Sound, human population 20, deer population 15 to 30 depending on who you talk to. The environment is lush and the deer lack nothing. They don’t even have ticks, apparently. There are more bucks than does, and this year there were at least 3 fawns that I know of. I recently read that whitetail deer could double in population in just two years. The island is only about 200 acres total. So how does one calculate the carrying capacity of the island? At what point do the deer need to be thinned to keep everything healthy? Thanks.”

Response: First, good call in gathering information on deer management for your island. It does not sound like you have a deer overpopulation dilemma on your hands just yet, so hopefully I can offer some pointers on what to look for to manage the deer and habitat found in your area. Deer, like most animals, are self-limiting. When deer numbers get high and food availability gets low, individual deer start to lose body mass, become weak and ultimately die. When a bunch of individual animals die the population crashes. Wildlife management at its very essence is designed to harvest, to utilize those excess animals well before malnutrition brings down an entire population. Continue reading “Determining Carrying Capacity for Deer Management”