Buck Manager | Buck Manager

Fawns are Twins, But Not Identical

Most people, including me, find any variation in white-tailed deer quite intriguing. In fact, most hunters and deer managers even select for certain characteristics, specifically when in comes to antler configuration. Depending on the individual hunter, they may look to harvest bucks with really wide antler spreads, bucks with numerous points, bucks with non-typical antlers, or very old deer. Color is also selected for by hunters because if the opportunity presents itself, many hunters will not hesitate to harvest a uniquely-colored deer. However, I do not know of any individual or ranch that manages for deer color.

Although there is some amount of color variation between all living whitetail, we all know what a white-tailed deer should look like. They are usually some variation of brown on top with white under the body, on the throat-patch, around the eyes and nose, and let’s not forget the white under the tail. After all, they are white-tailed. We know how a deer should look, but this is exactly why any color variation, even minor, sticks out. We, as predators, pick up on any abnormality or weakness exhibited by deer. This is why we do not see many white albino deer or black melanistic deer–they occur rarely, and when they do, these deer are removed from the population by hunters or natural predators. That is unless these deer are found in protected areas, such as urban or suburban areas.

Such is the case with the city of Austin, Texas. Melanistic deer naturally occur in this area and show up again year after year. Black-colored deer occur throughout the United States in very small numbers, but apparently the gene pool for melanistic deer is well-stocked in Austin. From a genetic standpoint, this makes sense. The “normal” color observed in deer is the result of dominant genes. Any variation in that color is caused by abnormal, or recessive genes. Just as many deer management programs spare certain bucks to concentrate genes for specific traits, the melanistic deer in Austin, Texas, have been spared because they live in a developed area.

This has allowed the very recessive genes for black hair, at least in white-tailed deer, to be passed on in a “protected” area with little to no predators. And although these genes are concentrated, the genes are recessive and do exist in an open population. So not every deer is melanistic, but melanistic deer can occur when melanistic deer, or deer that carry melanstic genes (but look normal), breed. The take home message as it relates to deer management on your property is that certain genes–even rare ones–can be increased within a population if managed and protected.

How Many Deer are Too Many?

Let’s face it, most landowners want to see plentiful groups of white-tailed deer running around on their property. However, those interested in improving their herd through deer management practices should want to see healthy individual animals. Why is this, you ask? That is because healthy animals are an indicator of good deer habitat and animals in good condition make for healthy white-tailed deer herds. If individuals within a population are in poor condition, then the overall population itself is in poor shape. So although we may want to sustain as many deer as possible on a ranch, what is the ideal number or the target number? The quick answer is that carrying capacity is based on habitat and environmental conditions.

In short, it’s all related to soils and precipitation, which in turn determines the plant species that grow in a particular area. But even with that said, we all know that the quality of deer habitat can vary based on a variety of factors, even within a single county or even just a mile or two down the road. The previous few sentences probably did not help anyone develop a population goal for their property, but hopefully it did help in understanding that the carrying capacity for a particular piece of property can vary widely between regions, counties, and individual ranches. To help you get a handle on how many deer you should or could have, I have outlined three measurable factors that landowners and hunters can use to monitor the health of a deer herd.

Deer Body Weights

From experience, I can always determine if a property has too many deer for the available habitat based strictly on deer body weights. Deer are kind of like people in the fact that if food is available, they will usually eat it. Removing protein pellets, food plots, or any other type of forage supplement, there is only a limited amount of forage that deer can use on a particular ranch. If the ideal population size for a ranch is 100 white-tailed deer, then the property will support a population of 100 (or fewer) healthy deer. However, if more than this number of deer are on the ranch, say 130, then all of the deer on the property will be less healthy.

This phenomenon is most easily measured and assessed by collecting the field-dressed body weights of hunter-harvested deer off the property. The health of individual animals can be determined by comparing its body weight to that of healthy deer in the same age class. For example, mature (5 1/2+) and healthy white-tailed bucks anywhere in Texas should field-dress at least 125 pounds. Mature does should weigh around 80 pounds. Both sexes can easily weigh more than these quoted minimums, but they should at least reach these targets. Minimum field-dressed weights for healthy deer will vary depending on where in the country you are located, so contact your local wildlife department to get optimal field-dressed body weights (by age class) for your area.

Reproduction Measured Through Fawn Production

Fawn production is a good measure of habitat and herd health because nature does not lie. Healthy animal populations, regardless of species, will have high reproduction, high survival, and good recruitment in environments that provide everything they need. Animals need food, cover, and water, and white-tailed deer on no different. If your property provides high-quality deer habitat, then the cover and resulting food are in place.

The availability of food, as it relates to habitat condition, really impacts fawn survival. This is why fawn crops are poor during drought and high during years with high amounts of precipitation. Habitat that is being over-used by too many deer will be in poor condition, even during a “good” year. In addition to field-dressed body weights, fawn survival is generally a good measure of herd health. High fawn survival means healthy habitat. To estimate the fawn survival of the whitetail herd found on your property you will need to conduct daylight deer surveys annually. A fawn survival rate of at least 75% (75 fawns per 100 does) is indicative of a healthy deer herd and healthy habitat.

Habitat Use and Condition

Biologist often use habitat condition, as measured through browse utilization by deer, as an indicator of habitat health. This is because trained individuals know exactly which plants deer prefer to eat, those that they will eat readily, and then those that are at the bottom of the list. As mentioned above, the availability of food is important for the health of individual deer as well as the herd as a whole. Although you do not have to become an expert in plant identification to successfully manage the deer herd found on your property, it would be a good idea to become familiar with the common browse plants on your property. This will allow you to identify browse consumption by deer throughout the year and from year to year.

Once you are able to recognize a few plants from each browse category (preferred, moderately preferred, not preferred), you will understand where on the buffet line the deer on your property are eating. However, there is a trick. Highly preferred browse plants will always be consumed at high levels. The real measure of habitat health will be determined by whether or not deer are eating plants they really do not want to eat.

Developing a Target Number for the Deer Herd

Each ranch manager should determine the whitetail carrying capactiy for their ranch. This number may vary over time, but without a goal there is no need for deer management. How can one manage for something if they can not measure or detect changes? As you can tell, record keeping becomes very important if you expect to monitor the progress of the deer found on your ranch. In short, there are two ways to determine the ideal deer population size for your property. You can work from the top down or from the bottom up.

A top-down approach would be to contact a state biologist, have them come look at the habitat on your property, and then them give you a ball park number on how many animals your habitat will carry. A bottom- up approach would be for you to monitor individual deer body weights and estimate fawn production annually. In either case, you can use the same information to make the appropriate changes. If the body weights of field-dressed deer are less than optimal for the area and fawn production is low, then there are too many deer for the habitat. Adjust the population carrying capactiy downward and shoot more animals. If, however, deer are in good condition and there are plenty of fawns, then it may be possible to increase the population incrementally as long as negative changes are not measured.

Of course, the above data will be of most benefit if you are also conducting annual camera surveys or spotlight surveys. And if you are at all serious about deer management, yearly deer surveys are a must for your ranch. Deer surveys are designed to help you estimate the number of white-tailed deer on your property, but then, using body weight and fawn production data, you can determine if that is the right target for you. Once you have identified the carrying capacity for your ranch, then it’s just a matter of conducting annual surveys and harvesting the excess population. Of course, if you keep the herd at carrying capacity, then that fawn production data will give you a pretty good idea of how many animals will need to be removed each year!

Whitetail Fawn Eaten by Feral Hogs

For as long as there have been white-tailed deer there have been predators that have relied on deer as a source of food. Of course, before feral hogs (and European wild hogs) were introduced into Central and North America, that was one less predator whitetail had to worry about. Not so now days, with hog populations on the rise throughout much of the whitetail’s range.

Not only do feral hogs compete with native wildlife for food, habitat, and space, but hogs also have direct impacts on wildlife populations through predation and direct consumption. Every bite of native food that a hog eats and every fawn that a hog kills takes a little more from the deer herd on your property.

Whitetail doe gives birth to a fawn

Predators and White-tailed Deer

I’ve examined the relationships between deer population management and the impacts of whitetail predators — particularly coyotes — and deer populations can still thrive in the presence of healthy predator populations as long as high quality habitat is available for whitetail.

However, even in the best habitat predators will have some impact on white-tailed deer populations. I think most landowners, deer managers, and hunters understand this fact. But even so, it can be difficult to sit back and wait for predators to do what they do best considering the time, energy, and money that property owners and hunters put into their property, leases and deer management programs.

It can be even more discouraging when such offenses are caught on camera. Such is the case with the attached photos that I received via email recently.

Feral Hog Eats Deer Fawn

One hunter, located in Schulenberg, Texas, sent me some very unique game camera photos that captured a whitetail doe giving birth to a fawn. The photos are interesting because rarely do we have the opportunity to see a fawn being born, but in this case we’re lucky because it happened right next to a deer feeder and it was all caught on camera.

As you look through the pictures, the photo series shows the whitetail doe setting up in front of the camera, giving live birth to the fawn, and then cleaning up the newborn deer. All of this happens between roughly midnight and 3:30 a.m. in the morning.

Though these photos give us an idea of the amount of care and attention a whitetail doe gives a newly-born fawn, the real drama takes place shortly after 4:00 a.m. In the first photo below, you can clearly see that two large feral hogs arrive on the scene. Also, if you look very carefully, you can see that the spotted fawn is lying flat on the ground directly in front of the feral hogs.

What happens next we will leave to imagination, although the outcome is very real — and we can only conclude that the hogs did kill and consume the 4-hour old fawn. The last photo shows a turkey vulture showing up on the scene to pick at any possible remains.

Do Wild Hogs Eat Deer?

Yes. Food habit studies on feral hogs have often found white-tailed deer tissue in hog stomach contents, but there has also been debate on whether hogs actually killed the deer or simply consumed their flesh post-mortem as carrion. The take-home from this series of photos is that yes, feral hogs do eat white-tailed deer. It also appears that new-born fawns are quite susceptible to feral hog predation.

Deer are most susceptible to predators as fawns, but especially just hours after birth. The only remnants the landowner found of this fawn were some of the skin and a small portion of the skull cap. He concluded his email to me in this way:

“As far as viewing the pictures, it seems everyone that sees the sequence of photos has the same reaction: lots of oohs and awhs quickly followed by disgust and anger. But I guess life and death in the wild is never fair… it’s just about survival of the fittest.”

On Predators and Whitetail

Fawns are the deer most susceptible to predation and this fact is also why it is important that fawning within a deer herd take place over a relatively short time period. Tight fawning dates, meaning a very short window from the first fawn born to the last, means whitetail fawns within a local population hit the ground almost simultaneously and predators only have limited access to them during the period when they are most vulnerable.

After a short period of time, fawns are much more alert, mobile and are able to more or less fend for themselves. Managed deer populations tend to have higher annual recruitment rates that those not management and part of the reason is compressed fawning dates.

The length of the fawning period for your area is directly related to the buck to doe ratio. A high percentage of doe deer in the population means a single predator has a greater chance of encountering a new-born fawn because the fawning dates will be spread out. Anyway you slice it, there is a lot to consider when it comes to predators, even such as feral hogs, and deer management. Thanks to Michael Jurica for submitting these photos.

Antler Growth in White-tailed Deer

Testosterone levels control just about everything on a white-tailed buck, including antler growth and development. During this time of year, a buck’s testosterone level is quite low, but those levels will begin to increase as summer comes to an end and the fall season rolls around. Testosterone levels will peak just prior to the rut. It is during that time when bucks become very aggressive towards one another, establish breeding dominance, and prepare for the rut. That time of year can be rough on a whitetail buck.

When I received this photo of three white-tailed bucks in my inbox a couple weeks ago, the sender wrote that the deer on the left and the right (in the photo above) were bucks. I zoomed in for a closer look and noticed that not only two, but that in fact all three of the deer were bucks. And the photo makes sense because whitetail bucks have low testosterone during the spring and summer, and they can stand to be around one another.

This is the reason for spring and summer bachelor groups. Furthermore, does tend to be more solitary leading up to fawning season. Does will not associate with bucks, or other does for that matter, until several days to a couple of weeks after the fawns are born.

Whitetail Deer Management: Three whitetail bucks take a drink on the outskirts of Houston

There are other reasons, besides low testosterone, why bucks will not fight very much during the spring and summer. It is because their antlers are quite fragile. Growing antler material is basically is pre-formed cartilage, so trying to fight each other while in velvet would be like butting their noses together. It would not feel good and there would be a lot of blood shed.

Bucks, even with velvet-covered antlers, still have minor disagreements. They, however, settle these spats by standing on their hind legs and using their front legs to kick in the same manner that we often see does fight. Bucks fight only in this particular manner when in velvet during the antler growing period. During the remainder of the year bucks may fight in this manner but often choose head-to-head combat.

Whitetail bucks change drastically between spring-summer and the fall season. With rising testosterone levels, antlers complete their growth and bucks are spurred to shed velvet and rub on trees and shrubs. This rubbing activity and increase in testosterone creates noticeable changes in a buck’s body. During the spring and summer bucks have doe-like necks. With decreased hormones and no antlers up top — and no one willing to fight —their neck muscles shrink in size.

However, increased testosterone and antler rubbing soon condition a buck’s front-end and neck into a fighting machine, typical of what most hunters expect to see during the hunting season. This conditioning helps individual bucks compete for does and helps them submit does, as well. After all, during the rut hunters often see does running away from the bucks!

Whitetail bucks change drastically between the breeding season and the “off season.” These physical changes, in terms of their body and antler growth, are related to an individual buck’s testosterone level. Bucks have low levels of testosterone during the antler growing period and high levels of testosterone just before and during the breeding season.

These physical changes can make it difficult for most hunters to estimate the age of a deer on the hoof during the summer months, but whitetail bucks quickly “whip themselves into shape” for the big show as fall approaches.

Fawning Habitat is Important for Deer Populations

Good habitat is important for a healthy white-tailed deer population and necessary for successful deer management. Not only does high quality habitat provide nutritious food and great cover, but good deer habitat also provides a good amount of grass, especially during the fawning season. Deer do not consume very much grass at all–it usually comprises less than 8% of their diet on an annual basis–but tall grass is very beneficial to fawns.

For white-tailed deer, fawns are typically dropped about 7 months after conception. Because the gestation period averages about 205 days in whitetail, the major fawning period is roughly 7 months after the peak of rut. Does bred early in the rut will fawn earlier and those bred late will fawn later, but the majority of deer fawns in a given area will hit the ground at approximately the same time, usually during about a two week period. Fawns, however, don’t usually get a lot of attention from hunters. And there are probably a few reasons.

First, fawning takes place during the late spring and early summer. Many hunters are still “checked-out” at this time of year only to return in late summer or early fall to plant a hunting plot or fill their deer feeders. Secondly, we are talking about fawns here, not big, gigantic, muy grande bucks! Hunters hunt bucks, not fawns. With that said, land owners interested in deer management realize that mature bucks do not just appear out of thin air.

So let’s talk about fawns. The early life of a fawn and the life of an adult whitetail are quite different. For the most part, adult deer do not require a whole lot of grass. The only grass they use in their diet is young and tender. Fawns, on the other hand, need grass and do not even know it. First of all, moderate to high grass makes excellent fawning cover. Not only does this herbaceous cover help conceal newborn fawns, but tall grass is indicative of good white-tailed deer habitat, which is needed by nursing does to raise healthy fawns.

In addition, good fawning cover decreases the impact predators can have on a yearly fawn crop. Research has shown that high quality deer habitat can produce good fawns crops even with dense predator populations. However, even on properties where predators are controlled, if the habitat is poor then fawn crops are not necessarily good. This does not make sense to some people, but it’s true.

First, poor habitat can be caused by many things, but over-grazing by livestock is the number one reason for low-quality habitat. A lack of ground cover makes it really easy for predators (even if few) to find newborn fawns. In addition, generally poor habitat means does will have difficulty finding adequate nutrition to produce milk and raise fawns. You see, over-grazing by cattle leads first to an over-use of grass and then to an over-use of browse species. Over-grazing by goats first leads to an over-use of browse species and then to an over-use of grass species. In either situation, it leads to poor deer habitat and poor fawn crops. Properties that lack at least some open, grass-dominated areas also provide poor deer habitat overall.

Any practice that removes ground cover during the fawning season should be discouraged if you want to improve the fawn crop in your area. The mowing or haying of fields should be postponed at least one month before fawns drop until after the bulk of the fawns have been born, which is usually around the end of June. However, you can figure this out for your area by adding 8 months to the time when the peak of the rut occurs.

Additionally, keep an eye on your predator population and do what you can to control them, but especially in areas with less than ideal fawning habitat. There is quite a bit of time between now and deer season, but the deer you should be thinking about is the one you will be harvesting about 5 1/2 years from now.