Cull Bucks & Management Bucks [ACTUAL Herd Effect]

If you have spent any amount of time online with other deer hunters, you have definitely seen someone post a one or two year old buck with a caption of something along the lines of  “sure am glad to get this cull buck off the property”. The sad part is, a lot of those hunters will call any deer they shoot that isn’t massive a cull or management buck. 

A little buck is not a cull buck, and most hunters have a skewed idea of what a cull or management buck actually is thanks to TV. Sure, cull and management bucks exist if you want to label them, but more often than not, deer that most hunters would label cull bucks are really young, really old, or have a temporary antler defect. 

Before we get into the thick of it, let’s define what a cull buck and a management buck actually is. Yes, they can be different!

What Is a Cull Buck?

A cull buck is a deer that has inferior or smaller antlers than average for his age class on a given property. A cull buck can also be defined as a deer with abnormal antler growth that is undesirable. These deer are harvested or “culled” in an effort to increase herd antler genetics. 

What Is a Management Buck?

A management buck is a buck that a property manager wants to remove for any reason. The term management buck is sometimes used interchangeably with “cull buck”. Although “management buck” is a wider term that can be used for any buck removed under any kind of deer management strategy.

The Deer You Should NEVER Cull

Whether or not culling bucks is an effective management strategy is something we will get into later, however, what may be more important is correctly labeling a cull buck. 

One of the most important things you have to realize is that the term “cull buck” is extremely relative. A cull buck from the midwest might be a trophy buck in Florida. You have to compare the buck to the local population, not random photos of deer you see online; even if they are from your same state. 

Next, you have no idea what a deer is going to look like next year. Sure, some deer may have antler characteristics that shine through year after year, but that little six pointer could be a great eight or ten the next year. You have no idea. 

I am definitely not the guy that always says “he needed another year”, but my point is that you should avoid culling young bucks altogether. If a deer is four years old, and has a small rack, sure cull him. If he is one or two years old, he still has plenty of potential to be a quality deer if you leave him alone. Although that is going to lead us down another rabbit hole because the large majority of hunters are terrible at aging any deer that isn’t a fawn.

Assuming you can identify one and two year old deer, don’t label them as cull bucks. Even if they look abnormal. One kind of yearling that everyone likes to cull is a spike. Numerous studies have been done on spikes showing how they can turn into quality deer as they age. Having spikes on your property is not the worst thing in the world, and I actually wrote a whole article about it that you can read here if you want to know more about what spikes can actually tell you about your property. 

Why You Are Burning a Tag

There are more than likely a lot of deer on your property, and if you have a good buck to doe ratio, there are plenty of bucks. Most states give out one or two buck tags a year to each hunter. If you use one of your tags on a cull buck, you are really wasting it. If taking that cull buck made a real difference, you might think it was a tag well spent. However, that buck has already caused whatever damage you were trying to avoid.

He Has Already Bred Does

The plain truth is that his genetics are already out there. A single buck can breed around 7 to 8 does per year. If you have a denser buck population, your bucks may breed between 2 and 5 does during a single season. If you take out a cull buck that is 3 years old because he has smaller than average antlers, he has had at least 2 full ruts to service does.

That means if you shot that 3 year old in September, he has still spread his genetics to anywhere from 4 to 16 does, which means he sired somewhere around 6 to 30 fawns over his two ruts. A safe bet would be to say he sired a dozen fawns, and you simply don’t have the means or the tags to identify and harvest those deer. So you really can’t “remove his genetics” just by taking that single deer. Plus, his brothers have roughly the same genetics. 

The Genetics of One Deer

If you ask wildlife biologists, they will tell you that a single organism has little to no effect on the overall genetics of a population as a whole. If a single dominant organism was able to spread their genetics throughout the entire population, eventually, they would all die from the same disease. 

This is avoided by the way DNA is actually passed down. No animal is a direct 50/50 of their parents, there are plenty of mutations that happen. While offspring of course get a majority of their traits from their parents, even after 3 generations, a great grandparent’s DNA can be fairly different from their descendants. 

Bucks Have Mommas Too!

Remember all of those fawns your cull buck sired? Since the cull buck has bad antler genetics, it is safe to assume his offspring would have bad antler genetics too. Half of his offspring are going to be does, how will we find them when we are picking out deer to cull? It is true, if you breed a doe with bad antler genetics with the biggest farm deer in the country, the offspring would likely not be nearly as large as the father. But without a pedigree, how do you tell?

Well, you don’t. The fact is, does also contribute just as much to antler genetics as a buck, or else the buck offspring would have the same antlers as his father without a hefty mutation. So any doe you see walking on your property could have antler genetics that are just as bad as that cull bucks, or worse.

Be Proud of What You Shoot

I also want to make something clear, a buck labeled as a “cull buck” is a buck that you are saying you specifically shot because it was inferior in some way and you wanted to remove it for the sake of your population’s antler genetics. 

If you just wanted to shoot a young buck, that is fine! Shoot all the deer you want, spikes, or boonies, whatever makes you happy. Just don’t call it a cull buck because you think people will say something about it being small. 

Some of the deer, and hunts, I am most proud of are tiny bucks, and I will show off this year’s 3 pointer to anyone. Especially those guys that have shot less than a dozen deer and are too good to shoot a little deer. After you shoot 50 or 100 deer, you can go window shopping in the woods. Until then, figure out what it actually means to deer hunt.

What the Science Has to Say About Culling Bucks

I have harped on culling quite a bit, but why take my word for it? Instead, let me talk about some really impressive research that some very accomplished deer biologists did at the Comanche Ranch in southwest Texas. I am going to summarize it here, if you want more details you can read the NDA article about it.

From 2006 to 2015, the wildlife biologist at Comanche Ranch, Donnie Draeger, teamed up with four other researchers (Dr. Charlie DeYoung, Ph.D. student Masa Ohnishi, Dr. Randy DeYoung of Texas A&M-Kingsville, and Dr. Bronson Strickland of Mississippi State University) to really find out if culling works.

They chose three sections of the Comanche Ranch to test on. One would experience an intense cull each year, another would experience a moderate cull, and the last would be a control group and experience no cull.

• Intense Cull Criteria – yearlings with less than 6 points, 2.5 year olds with less than 8 points, 3.5 and 4.5 year olds with less than 9 points, and 5.5 year olds or older that grossed less than 145 Boone & Crockett.
• Moderate Cull Criteria – 3.5 and 4.5 year olds with less than 9 points, and 5.5 year olds or older that grossed less than 145 Boone & Crockett. (same as intense cull, but without culling younger deer)
• Control Group – no bucks captured in the control group were culled

For the duration of this long study, they flew around in a helicopter and captured deer with net guns. Where do I apply for that job?! They ended up performing 4,264 captures on 2,503 bucks. Many of which were captured multiple times throughout the many years. That’s an impressive amount of captures!

When a buck was captured, it is culled if they fell under the antler restrictions laid out in the cull criteria. This was done with special research tags, and a total of 1,333 bucks were culled. The study only culled bucks for 7 of the 10 years, however, it was not clear to me if it was the first or last 7 years. 

When the researchers caught a deer, they estimated each buck’s age based on tooth replacement and wear, collected a DNA sample, measured the antlers, and inserted a microchip PIT tag in the ear if they chose not to cull it.

So What Happened?

So did the culling work? Their answer was overwhelmingly no. In the intense culling area, there were so many bucks culled that the buck to doe ratio went from 1 to 1 all the way to 1 buck to every 6 does. That is way out of whack, and terrible for a deer population. If you want to learn a bit more about buck to doe ratios and what they can mean for a population, I wrote a whole article about it you can read right here. 

They even had a 93% cull rate for yearling bucks. This effectively wiped out their buck recruitment every year. So eventually, the bucks that were left were big, yeah, but they could not breed all the does, and more often than not, their offspring did not exceed the culling criteria the next year.

The lack of bucks made average conception dates fall later and later in the year, which led to more late-born fawns. Those fawns had less time to grow in their first year, so they ended up with smaller bodies and antlers for their age, which meant that they were culled. 

This whole cycle created a buck population crash in the intense cull area, and there didn’t seem to be any benefit. The end result was that the average buck that was captured near the study in the intense culling area did not present larger antlers than the average buck captured in the control area during the same time.

The moderate culling area also saw zero benefit. However, since they were not culling younger deer in this area, they did not have the buck population decline like they did in the intense culling area. Still, at the end of the study, there were no significant increases in antler size between deer in the moderate culling area and the control area.

What The DNA Says

The DNA was the best part of this study, and it actually explains why culling didn’t work at all. By the end of it, they were able to connect offspring to 963 sires and build paternal family trees. Since they knew the antler measurements of each buck in the study (sometimes across multiple years), they could see how those genetics were passed down. 

Based on that data they created what they called a “Breeding Value” for each buck. Bucks with a larger breeding value produced offspring with larger than average antlers relative to the local population, and bucks with lower breeding values produced offspring with smaller antlers relative to the local population. 

Here is the weirdest part, breeding value was not correlated with the sire’s antler size. That means they found no relationship between how big a fathers antlers were, and how big the offspring’s antlers were. They actually found offspring from cull bucks that had above average antlers, and offspring from bucks with above average antlers that had below average antlers! Of course, the opposite was also true. 

Their overall conclusion was that antler size is not an indicator of breeding value, and you could not predict how large or small an offspring’s antlers would be by looking at the father. Wild! Put into layman’s terms, a buck with big antlers does not necessarily make offspring with big antlers.

Stop Listening to the TV

I love to sit down and watch a hunting show just as much as the next guy, but I think they are the main reason for some of the snobbery around shooting small bucks. So hunters just call their small bucks cull bucks and that makes it socially acceptable. 

I think a lot of this comes from TV hunters filming shows on managed deer ranches. A lot of the time they get to hunt those places for absolutely free, especially if they are airing their show on national television. However, there is zero guarantee that a ranch will book more hunts because of that show, and letting that TV hunter shoot their biggest deer is literally taking money out of their pocket. 

So what do they do? They give the hunter a “cull buck” or “management buck” to shoot. Since the hunter has nothing to lose from a free place to hunt, they do it. Although they know they are going to shoot a smaller deer, so they make a big deal about it being a management buck because they have nothing better to talk about. Then they convince their viewers that they are providing a service to this awesome ranch, and that they need to book a hunt.

You see where I am going with this? The fact is that 99% of hunters do not hunt on managed ranches, and you can not alter the herd genetics with a single tag, or 1,333 of them as we saw from the study.

How to Really Boost Your Average Antler Size

Hopefully, I have convinced you that culling bucks is a waste of a tag, and if you are going to shoot a little deer anyway, be proud of it; not embarrassed. Although if you are serious about deer management and you were using culling as a way to honestly try to improve your herd, here is what actually works for increasing antler size.

All you have to do is buy my brand new antler supplement that makes Boone & Crocketts out of yearlings in two weeks!!  No… that is what you would see watching sell-out TV hunters. 

What you can actually do is focus on increasing the nutrition available on your property. Things like food plots and water sources are incredible for a deer population. If you do it right, you can realistically see your average antler size go up by 15 inches or more over a few years. 

If you want to learn more about that, you can read my other article, “How to Attract and Hold Bucks on a Small Property” where I go more in depth about adding everything deer need to your property like food, water, and cover; as well as a handful of tips for bringing in more bucks. 

Thank you for reading my article! I hope you enjoyed it, and if you have any questions or feedback, please send me an email at Patrick.Long@omegaoutdoors.net. If you want to learn more about me or Omega Outdoors, visit my About Page. Otherwise, I hope you have a great day, and check out some of my other articles while you’re here!