As the snow falls today in Central Texas, I can’t help but think about the white-tailed deer throughout the country. I’m not just talking about the animals living right outside my door, but everywhere throughout the whitetail’s range. This is the time of year when habitat conditions are tough and when the nuts and bolts of deer population management are tested. After all, the white-tailed deer hunting seasons are over and the remaining deer are carryover, the core herd of the upcoming hunting season.

At the heart of deer population management is food availability. With late winter upon us, even though spring is just around the corner, white-tailed deer food is scarce over the landscape. Late winter is the most nutritionally stressful time of the year for a deer. At this point in time, the deer herd on every ranch should be at or below its base population size—the maximum number of animals that the habitat can support. Otherwise, the deer herd is at risk of a die-off from being malnurished due to inadequate food resources.

The ideal number of deer for a property can be somewhat subjective at the beginning of a deer management program, but keeping a close eye on habitat and deer body conditions will let landowners know where their base population should be. Less than desirable habitat conditions and lower deer body weights mean the population needs to be trimmed down even further. Big, healthy deer may suggest that the whitetail herd could be increased, but should it?

This is where two schools of thought regarding deer density and food availability collide. In nature, a given amount of habitat can only support so many animals until the food runs out. This law of nature obviously applies to white-tailed deer, but we as humans have the ability to add more food. Too many times, managers perceive the ability to add food to the system as a way to increase the number of animals that their property will support. However, this is just not so. Additional food does not increased the number of animals that the PROPERTY can support, it merely increases the total herd size.

So why is this a problem? The degree to which this becomes a problem depends on how far the actual deer population is from the ideal deer population for a particular property. A deer herd that is perfect in size for a property will have no problem getting through the nutritionally stressful times of late summer and late winter. This herd can even be provided with supplemental feed to ensure that all deer maintain maximum body condition and health, even though they don’t require it.

However, what happens as the deer herd gets further away, well above the ideal population size? Well, without the addition of food, deer begin to die. This is not just bad deal for the deer that have died, but an indicator that the herd is in poor condition. Once deer begin to die, you will be hard-pressed to find any deer that is in average to above-average condition within the herd. This is why deer seasons as we know them are in place—to maintain healthy deer herds.

But wait, why can’t we simply add more food and maintain more deer? Not only is this costly, but even as popular as supplemental feeding is, most properties do not have supplemental feeding programs for deer. Besides, food is only supplemental if the deer on a property can survive without it. If a deer herd requires feed, then it’s just that—feed. Removal of the feed jeopardizes every deer on the property and the herd.

In closing, winter is tough on all animals, including white-tailed deer. Looking out on this cold winter day makes me think about how limited food resources are during late winter in the deer’s natural environment. The most important component of white-tailed deer management is to keep the deer herd at a healthy level for the available habitat. Not only will this benefit the deer herd, but their habitat as well. And they need every last bit of it at this time of the year.

A deer hunter never expects to see giant warts or tumor-like growths on a white-tailed deer, but they do occur. Over the years I’ve seen many of photos of both live and harvested deer with “tumors,” although I’ve never seen one while in the field. The technical term for these growths is cutaneous fibroma and it’s caused by a virus. From a deer management perspective, there is not much you can do to keep wild deer from getting fibroma.

Cutaneous fibromas (warts) are caused by a naturally occurring virus of the deer’s skin. The virus that causes these unsightly warts in deer is believed to be transmitted through biting insects and/or direct contact with damaged skin. Once the virus enters the skin, warts begin to form. As the warts increase in size, the skin surrounding them is typically hairless and grayish in color. The number of warts on an infected animal can vary from one to several hundred, they can sometimes clump, and can in some cases end up covering much of the deer’s body.

For the most part, these warts will not cause a white-tailed deer any major problems. However, sometimes the growth of the wart can indirectly cause problems by restricting the consumption of food or the deer’s breathing. Although death from fibromas in deer can occur, death from warts is not always imminent it seems. There have been many hunter testimonials of white-tailed deer with warts “shaking them off,” so to speak. I can’t say for sure.

From a deer hunter’s perspective, warts are quite unsightly. Since fibromasts are a virus of the skin, they willl be removed if the deer is skinned. Notice I said IF the deer is skinned. Although the meat of a deer is typically not affected, most hunters that harvest a deer with a large number of warts are hesitant to put the meat in the freezer. This is understandable and probably the safest thing to do. I’ve read some research that found a buck with warts also had internal and cancerous fibromasts.

The take home message today is that warts occur naturally in white-tailed deer populations. Fibromasts can occur on any deer, healthy or otherwise. With that said, they occur rather rarely and there is nothing that can be done from a deer management standpoint. Deer are the only host for the virus, so fear not for yourself should you find yourself standing over an infected animal.

The benefits of supplemental feeding of white-tailed deer have been witnessed by researchers and landowners alike. In white-tailed deer management today, the combination of habitat management and supplemental feeding go hand-in-hand on most properties. Though some landowners choose to supplement through food plots, others use protein pellets. Regardless of the product used to supplement deer, the primary reason for providing supplemental feed is to improve the overall health of each individual animal in the herd.

The health of a white-tailed herd is readily measured through the individual body condition of deer, the antler quality of bucks, and fawn production. Although the presumed outcome of providing additional food is better and healthier deer, landowners often look for different inputs—or different food options. I’ve been asked time and time again over the years about feeding whole soybeans as a supplement for whitetail. It can be done, and it can be done successfully, but it’s always good to look at the pros and cons.

First, let’s not confuse baiting deer with supplementing deer. Baiting deer with corn can be great for attracting deer for the purpose of harvest, but corn is not a supplement. A true supplement adds nutritional value to an individual deer’s diet. Sounds simple enough, but why would a deer manager consider different options for supplementing deer? Well, the big concern are typically costs.

The dollar does not go as far as it once did, so hunters and deer managers are constantly looking for less expensive options. Currently, corn is $7, roasted soybeans are $12, and protein pellets are $11 per 50 pound bag (depending on where you buy them). Corn only offers 6 to 7% protein, soybeans average about 40% protein, and the pellets I quoted above are 20% protein. All of these products get cheaper at bulk prices, but let’s look at the value. In other words, what your deer get for each dollar you invest.

Corn is an attractant so the value is that it will draw deer into your area. However, the money you spend on a bag of corn does nothing to actually help the deer other than making their belly feel a little more full. The addition of protein, however, really can improve the diet and body condition of individual deer. Soybeans and protein pellets are both more expensive than corn by weight, but the value (what the deer gets versus what you pay) is much better!

Soybeans, at 1.7 times the price of corn, deliver over 5 times the amount of protein when compared to corn. Protein pellets, at 1.6 times the price of corn, deliver over 3 times the protein. Soybeans also have 3 times the fat content of corn. The value of soybeans and pellets over corn is obvious, but there is more to consider when it comes to supplementing a deer’s diet. In addition to macronutrients (protein, carbs, fats), what about the essential micronutrients required by by white-tailed deer?

Protein is great, but deer can not survive on protein alone. Important micronutrients for whitetail include calcium, phosphorous, potassium, copper, selenium, zinc, and vitamins A and E. This is where protein pellets pull away, so to speak, from whole or roasted soybeans. Soybeans can have good levels of micronutrients, but not always. The nutritional value of the bean will depend on the conditions under which it was grown and this affects the macro- and micronutrient levels. This will ultimately impact the amount of nutrients that are digestible by deer. In addition, roasted soybeans have more (bypass) protein than raw soybeans.

Where they are readily available, soybeans are a practical way to supplement the nutrition of white-tailed deer. Of course, any food added to a deer’s natural environment should only be considered a supplement. Supplemental food is not habitat in a sack and can not be substituted for good deer habitat management. However, soybeans can be used effectively to supplement animals where good deer habitat exists, but micronutrient levels can vary.

Most hunters that have harvested any number of white-tailed deer have unfortunately found nasal bots. At first glance, what a hunter encounters looks like a large maggot. And it basically is, and they live in the cavities of the nose and mouth. Nasal bots are the larvae of a specific kind of fly that belongs in the genus Cephenemyia. Deer biologists actually find them in a high percentage of whitetail deer, particularly when a thorough examination of the head is conducted. From my experience, white-tailed deer in Texas are much more likely to have nasals bots than not.

These bots are specific to members of the deer family, which also includes elk and mule deer in the United States. Nasal bots begin life when the adult fly lays a group of eggs around the nose or mouth of a deer. The small larvae within these eggs are then released when the deer licks the eggs. The warm, wet saliva creates an environment that permits the “hatching” of the immature bots. These larvae then migrate to the nasal passages and occasionally into the sinuses where they molt into larger stages of the maturing larvae.

The mature larvae then move to the deep cavities in the deer’s mouth called the retropharyngeal pouches. The fully matured bots then exit and pupate in the ground until emerging as adult flies that begin the life cycle all over again.

To a white-tailed deer, for example, these bots are typically only a minor nuisance as they do irritate the lining of the nasal passages and move about in the retropharyngeal pouches. In fact, most sneezing and coughing of deer is assumed to be the result of nasal bots. From a clinical perspective, the bots do not cause deer any harm. No sores, infection, nor other problems have been reported even when the parasites are present in large numbers.

Hunters normally encounter nasal bots after the deer they harvested has begun to cool. After the deer dies, the body temperature falls and the bots begin to leave the nasal passages and oral pouches in search of a more suitable environment. These bots then exit through either the nose or mouth. Bots can also move in the wrong direction, or down the trachea (where it is usually warmer), and may appear to be in the body cavity of the deer even though they are not.

Lastly, nasal bots pose no disease threat to deer hunters and do not harm the venison. Remember, nasal bots are only found in nasal passages and around the mouth of deer. Deer “infected” with these harmless parasites are safe for human consumption, although I suspect many unknowing hunters have discarded carcasses after observing an ugly larvae crawl out of a deer’s nose.

A couple of weeks ago, I wrote about the impacts of habitat quantity and quality on white-tailed deer harvest rates. Habitat quantity does not necessarily impact the harvest rate itself, but a property that provides a smaller amount of habitat must harvest fewer deer than a property that provides a larger amount of habitat in order to keep the deer population on the ranch stable. Habitat quality, however, can vary between properties that provide the same quantity (in acreage) of deer habitat, which in turn impacts the health and productivity of the ranch’s deer population.

Habitat quality impacts deer harvest rates because herd productivity will vary between properties. If deer density is held constant, deer on a property that provides good habitat will be in better condition than deer on poor habitat. This superior body condition can be measured through increased body weights in animals and improved antler quality in every age class of bucks. Today, I will discuss how fawn survival, as effected by deer density and the buck to doe ratio, can significantly impact the annual harvest of white-tailed deer populations.  

Most hunters understand that fawn production is an important component of white-tailed deer management, but they fail to realize how annual fawn survival directly impacts the number of deer harvested each year. Fawn production (the number of fawns born) is difficult to measure, but fawn survival is not. A good estimate of fawn survival can be collected annually using daylight deer surveys in late summer and early fall.

Every hunter wants to see bucks—and we all know they start as fawns—but once a property reaches its ideal carrying capacity, proper deer density, and buck to doe ratio, then it is fawn survival that ultimately determines the number of deer that should be harvested each year. A year with low fawn survival will not add many animals to the population, so not many adult bucks and does should be harvested. On the other hand, a year with high fawn surival means many new animals have been added into the population, so hunters must remove deer to maintain the property’s deer population at the proper deer density.  

A healthy deer population will more productive than a stressed deer population. As a result, reproductive success, as measured through fawn survival, can be a good measure of the health of the local deer herd. In turn, good reproductive success is often reflective of good deer habitat. Habitat conditions will vary annually based on precipitation, but white-tailed deer found on good habitat will almost always have higher fawn survival than deer found on poor habitat, regardless of the year. And all this stems from habitat quality, which determines the condition of individual deer living on the ranch. Healthy does produce more fawns and healthy fawns have higher survival rates. It really is the cycle of life.

Many hunters fail to realize that fawn production is strongly tied to habitat quality and the body condition of individual deer. Case in point: Think about a property that has a good number of deer, but the number of bucks is relatively low. The guy managing the property thinks that not shooting does will eventually lead to more bucks. But it doesn’t work. What’s going wrong? Well, a bunch of unhealthy deer on poor habitat will not produce many fawns.

The typical problem that exist on properties such as in the example above are that there are simply too many deer! If a property can only support 50 deer and there are 100, then fawn survival will be low. It wouldn’t matter if the buck to doe ratio was 1:1 or 1:5, if there are too many deer fawn survival will be low. The proper remedy in the example above would be to remove a good number of the does so that the remaining does could raise fawns, thus leading to higher fawn survival. A 10% (4) fawn survival out of 40 does is less deer than a 60% (12)fawn survival out of 20 does! That also means 6 new buck fawns instead of only 4. This is just a simple example, but you get the idea. 

High fawn survival rates are great, but they also lead to the need for high deer harvest rates. This is why healthy deer herds maintain a low buck to doe ratio. Time for another example: Let’s say a ranch can support 100 healthy deer and the buck to doe ratio is 1:5, or 20 bucks and 80 does. A modest 50% fawn crop means that 20 buck fawns and 20 doe fawns will be produced. To maintain the population at a healthy density this means 20 bucks and 20 does must be removed during the hunting season—but there are only 20 adult bucks! If the buck to doe ratio was brought down to 1:1 then a modest 50% fawn crop would mean that 50 does would have 25 fawns, or approximately 12 buck and 12 doe fawns. The addition of these animals into the population would warrant shooting 12 bucks and 12 does. Luckily, there are 50 adult bucks and adult does to choose from. The hunters could harvest 12 bucks and still have a good age structure in the buck population.

Hopefully, understanding the dynamics of a deer population will help you identify each of these factors on your property and help you reach your white-tailed deer management objectives.The annual harvest rate of white-tailed deer on any property is determined by deer density, habitat condition, the buck to doe ratio, and fawn survival. Factors that impact the body condition of individual deer will impact the dynamics of the population as a whole. Good habitat will lead to higher fawn production and the need for a higher deer harvest rate, but managers can mitigate excessive production by manipulating the buck to doe ratio.