Cold Weather, Overpopulation Leads to Deer Die-Off

Every hunter wants to harvest a trophy buck, but when it comes to white-tailed deer hunting the reality falls somewhere between shooting a big buck versus deer overpopulation. On one hand, you have hunters that really just want to harvest a single deer, preferably a big, mature buck. Then on the other hand, you have deer numbers that need to be controlled. This will probably not come as a surprise to you, but the average deer hunter only wants to harvest one deer, or more precisely, one buck. While most hunters love seeing numerous deer while out in the field, an important part of deer management is population management.

The reason I bring this up is because just this last week ranches near Kerrville, on the western edge of the Texas Hill Country, were finding dead deer after several days of cold and wet weather. The cause of these deaths — malnutrition. And before assuming that these deer were confined within a high fence that maintained too many animals, I’ll let you know that they were not. In fact, most of the animals found dead were free-ranging white-tailed and axis deer, but they were all starving. Basically, the deer population of the area has exceeded the carrying capacity of the winter range. They were all competing for limited winter forage, and the weakest died.

Deer overpopulation can lead to winter die offs

Reports indicate that the found deer were in poor physical condition, hip bones exposed, backbones showing, and no internal fat. The rumens of most of the dead whitetails were packed with cedar, some dead oak leaves, and even yucca leaves. Axis deer rumens were packed primarily with dry grasses. The cedars (ashe juniper) in the vicinity of the dead animals were severely browsed. Obviously, the cause of death was malnutrition caused by overpopulation that was exacerbated by the cold, wet conditions that persisted over several days.

Axis deer are more susceptible to cold, wet weather than white-tailed deer because they are an exotic subtropical species, but the end result of malnutrition is realized when mixed with winter weather. Deer in less than optimal condition are always more susceptible to disease and death. Additionally, parasite loads can only make an individual animal’s situation worse. So how can winter die-offs be avoided?

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First, the deer population must be kept in check with the habitat. Sure, you may only want to harvest one buck, but realize that the health of each individual deer depends on the availability of food. Supplemental feeding can help, but only if it’s at an adequate level and of the proper type to support the deer population. Each deer impacts every other deer because of the competition for limited resources, but this contest can be greatly reduced if free-choice supplemental food is provided 24-7, year-round. When animals are found dead, remember that the weakest die first.

When monitoring a deer population, many factors can indicate potential deer management problems. Individual body weights, fawn survival (as an indicator of doe and habitat health), and habitat use can all be used to gauge herd health. With that said, pay close attention to the health of deer harvested early in the season. Underweight deer (for their age) are good indicators of a potential problem. In addition, if deer are eating undesirable species, such as cedar, they and the habitat are in very poor condition.

Fire Creates Better White-tailed Deer Habitat

White-tailed deer, like many wildlife species, prefer habitat that is at lower successional stages. Simply stated, deer like plant communities that are dominated by plants that are considered first responders after disturbance. Any disturbance helps set back plant succession, whether it be disking established areas, clear-cutting portions of forests, or natural or prescribed fire. And although hunters understand that deer management practices are designed to improve habitat, many habitat management practices are really only designed to mimic processes that occur naturally.

Of course, when it happens naturally land managers have very little control. Such was the case last year in Texas when the almost 15,000 acre Chaparral Wildlife Management Area (WMA) unexpectedly caught fire. It was March of 2008, but because of extremely dry spring conditions, a fire that started adjacent the area burned 95% of the state-owned WMA! Anyone that knows anything about the Chaparral WMA knows that the area is representative of South Texas brushland, but active habitat and deer management practices maintain a healthy deer herd that boast some big ole whitetail bucks.

Prescribed fire is an effective management tool for deer throughout the white-tailed deer’s range because most native brush species respond well by root-sprouting, regrowing, and providing high-protein browse. You see, most plant species are well-adapted to fire, but all deer managers that use fire as a management tool prefer prescribed or controlled burning. The fire that swept across the Chaparral WMA, on the other hand, was a wildfire. And although wildfires and prescribed fires ultimately have the same impact on native plants, prescribed fires are planned and allow burners the most preparation. Prescribed fires allow landowners the ability to pre-select the areas to be burned and the conditions under which they are burned.

Chaparral WMA Fire of 2008

For those interested in using fire as a management tool, it’s recommended that no more than 20% of a property be burned annually. This keeps different successional stages of plants located throughout the property and provides deer with optimal forage. I mentioned earlier that the wildfire that crossed the Chaparral burned 95% of the research WMA. Keep in mind that the perimeter of the area is game-fenced and very few deer were found dead post-fire, so that left all the deer found on the 15,000 acre property about 700 non-burned acres to forage. But white-tailed deer are resilient animals.

Chaparral WMA staff and researchers from Texas A&M University-Kingsville used the effects of the wildfire to monitor how deer living on the area would respond. What would deer eat in the short-term? Would there be enough food to maintain body condition and support fawning? That was just a few of the questions managers needed to answer to determine if the deer herd could respond the the widespread setback in habitat.

It’s important to note that the month of March is smack-dab in the middle of a white-tailed does’ pregnancy. And pregnancy requires a high amount of dietary input. Researchers collected does at two week intervals from mid-April to mid-June and recorded live weight, body condition, rumen contents, and the number and size of fetuses. A total of 28 does were collected and 23 pregnant does carried 6 single fawns, 16 twins, and 1 set of triplets. Shortly after the fire, rumen contents consisted primarily (90%) of cactus and grasses. However, deer shifted to forbs and mast (fruits) as these foods became available after the fire.

 Chaparral WMA Post-Fire

Data collected on the Chaparral WMA found that deer were able to maintain body condition and pregnancy after a large-scale fire. However, the management area did have a lot of things going for it that may or may not be available in some areas. First, the deer herd was below the carrying capacity of the land prior to the fire. In addition, the area was fortunate to have an abundance of cactus that provided a moisture-rich post-fire food for white-tailed deer. Although deer were able to switch their diets in order to survive, would this be the case in your area after a wildfire?

Fire is one of the most beneficial tools in wildlife management because when used properly it is very economical. In addition, fire releases nutrients that are bound in dead organic material, fire stimulates the germination of certain plant species, and fire controls plants such as blueberry cedar that are not fire adapted.  And although we have learned that whitetail can cope with large-scale fire in South Texas, I do not recommend burning more than 20% of your property on an annual basis. Just keep in mind that with burning 90% of the work takes place before you strike the first match.

Cottonseed as a Supplemental Food for Deer

Cottonseed for Deer

A big part of deer management is ensuring the physical health of individual white-tailed deer. Supplemental foods can help, but is cottonseed for deer a good idea? Possibly, as healthy deer makes for a healthy deer herd. Individual deer health is important for maintaining body mass, promoting maximum antler growth in bucks, and optimal milk production in does. Furthermore, healthy does means better annual fawn survival.

The energy and protein requirements of deer have become more understood over the years. Consequently, deer managers now focus much of their attention on meeting and exceeding the food requirements of white-tailed deer. This can be done in either of two ways. The first is through native habitat improvement. The second is by providing supplemental food. In some areas, feeding cottonseed for deer is an option that should be considered.

Feeding Cottonseed to Deer

Pelleted protein ranges from 14-24 percent protein and is readily available throughout the whitetail’s range. Protein pellets are commonly offered in free-choice feeders for deer. Most managers use a pellet that provides 16-20 percent protein. Pellets are super easy to use. However, costs is always a factor and managers often consider other sources of protein for deer diet supplementation. Several sources of “alternative” protein include crop seeds such as whole cottonseed and soybeans. Let’s discuss cottonseed for deer.

In some areas, cottonseed is readily available and a real option for managers. However, cottonseed contains a compound known as gossypol. This is a toxic pigment that the plant naturally produces. It’s believed that gossypol discourages consumption of the seed by animals. I’m probably not making a case for feeding cottonseed to deer at this point, but wait, there’s more.

Furthermore, gossypol can reduce reproductive ability in some mammals when consumed at high rates. Okay, so stick a fork in cottonseed? Nope, it’s not done yet! Fortunately, recent research in Texas has found that white-tailed bucks are not negatively effected by whole cottonseed, even when it makes up a high percentage of a deer’s diet. Yes, I’m saying there’s a chance.

Cottonseed for deer as a diet supplement

Cottonseed Research

“We’ve done a series of independent projects,” said David Hewitt, the institute’s Stuart W. Stedman Chair for White-tailed Deer research. “In fact, we had five bucks on a 40-percent whole cottonseed diet and five bucks on pellets and chopped alfalfa from June through September. We looked at body weight, semen samples, and blood. We did not see any negative effects the first year.

The bucks on 40-percent whole cottonseed did lose some weight while the other bucks (on pellets and alfalfa) did not. Again, there were no toxic effects on the sperm or red blood cells. The bucks maintained their weight while the control group bucks gained weight. The doe weights did not change.”

Cottonseed as a Supplement for Deer

Cottonseed by the Numbers

At over 22 percent crude protein, cottonseed is a high-protein food alternative that is also rich in phosphorus. This is great news, as phosphorus is one of the most limited nutrients in native forages. Phosphorus is important for body growth as well as antler growth in bucks. In addition to white-tailed deer performing well on cottonseed, there are some other positives surrounding the feeding of whole cottonseed.

Non-target species, such as feral hogs, raccoons and other varmints do not eat whole cottonseed. Furthermore, these animals do not even have to be excluded from cottonseed feeders. They simply will not use cottonseed as part of their diets. This helps the bottom line by limiting consumption by animals other than the target species, whitetail deer. As we all know, a decent percentage of pellets is lost in waste, to both the weather and non-target wildlife.

Whole Cottonseed for Deer

All in all, cottonseed is a solid choice as a supplement for whitetail because it’s high in protein, high in fat, and it does not easily degrade under moist conditions. In fact, it does not get any easier than feeding cottonseed to deer. You can simply place cottonseed out on the ground or in a free-choice feeder. Standard whole cottonseed is not the only game in town. There is also a slightly modified product called EasiFlo, and it has some advantages.

EasiFlo cottonseed has the same nutritional benefits as regular (fuzzy) whole cottonseed, but is starch-coated to improve handling. This new cottonseed flows freely and can easily be augered through traditional grain-handling equipment. This choice really does make feeding cottonseed for deer easy. It also increases the options for the deer manager and hunter.

Feeding Cottonseed to Deer

Cottonseed for Bucks

Whole cottonseed as a supplemental food for deer is great for maintaining the physical health of a herd. It is especially effective for improving the body condition of bucks following the rut. Because cottonseed is high in protein and fat it allows post-rut bucks to put weight back on rapidly, meaning more energy is reserved for antler growth. Following the end of the breeding season,  new antler growth kicks off just a few months later. You do not want bucks struggling to put on weight at that time.

Feeding cottonseed will increase deer body condition, help improve annual fawn production and allow for increased antler development in bucks. However, cottonseed as a feed it should not be considered a complete ration for white-tailed deer. It’s not a one-stop-shop, but whole cottonseed is still a good supplement for whitetail. What is makes up in protein and fat it lacks in some nutrients.

Sizing Up Cottonseed for Deer

Whole cottonseed lacks many of the micro- and macro-nutrients that protein pellets contain. After all, pellets are developed to serve as a complete ration/diet for deer. However, cottonseed fits the bill for free-ranging deer in good habitat. Whitetail will pick up other necessary nutrients from other aspects of their diet. Although cottonseed has many great qualities, its availability may be limited in your area. This is the primary reason why more managers do not use cottonseed for deer.

Remember, regardless of whether you decide to supplement a deer herd through protein pellets, crop seeds or food plots, supplements are only intended to compliment native forage. Supplementation is most important during periods of stress. With this in mind, cottonseed is well suited to serve as a true supplement for deer. If it’s available in your area, cottonseed for deer is a good idea, especially after the rut in late-winter.

Are White-tailed Deer Getting Smaller?

Small Deer in Your Area?

Have years of heavy hunting pressure impacted deer body condition and antler quality in your area? It may be difficult to say with any certainty, but it seems plausible that deer hunters, which serve as predators, could alter the gene pool of certain game species. Last month, an article presented research that found hunting had a profound impact on wildlife, driving an evolutionary process that makes animals become smaller and reproduce earlier.

The study, which looked at both hunting and fishing, examined 29 different species and found, that under human pressure, creatures on average become 20% smaller. Do deer use more energy trying to evade predators, hunters?

Are White-tailed Deer Getting Smaller?

Feeling the Pressure

Article: “The human tendency to seek large ‘trophies’ appears to drive evolution much faster than hunting by other predators, which pick off the small and the weak.

Researchers reported, ‘It’s an ideal recipe for rapid trait change.’ In virtually all cases, human-targeted species got smaller and smaller and started reproducing at younger ages — making populations more vulnerable.

Hunters are instructed not to take smaller animals or those with smaller horns. This is counter to patterns of natural predation, and now we’re seeing the consequences of this management.”

Small Deer Study in Focus

This study makes some very good points with regards to hunters in general being trophy-oriented, but hunters and landowners partaking in intensive deer management programs are doing exactly the opposite. I have often believed that under certain conditions, such as extreme hunting pressure, particularly with regards to the overharvest of young bucks, that gene pools could be negatively impacted.

For example, some properties consider themselves “managed” by having an 8 point or better rule on harvested bucks. However, regular readers of this site know that the best yearling (1 1/2 years old) bucks can have 8+ points. This can result in decades of hunters high-grading their buck herd.

So by looking at common hunting practices this way, it becomes quite apparent that humans, particularly hunters, can impact gene pools. This is especially true in wildlife species that, like deer, are relatively short-lived. Common sense would conclude that just several years (which for deer would be several generations) of extreme pressure could alter whitetail genes in a given area. And if you are a management-minded hunter, that is exactly what you want.

Just as improper harvest can impact a deer herd negatively, proper deer harvest centered around a well-thought-out deer management program can continually change the gene pool for the better. In fact, this is exactly what the culling of inferior bucks is intended to do. Bigger-bodied whitetail bucks, much more often than not, grow larger antlers than their smaller-bodied counterparts. These bigger deer are also able to cope better with harsh winters, summer droughts, and better fight off would-be predators. In summary, help mother nature do her job and improve your white-tailed deer herd by harvesting those deer that are small for their age class.

The Culling of White-tailed Bucks is Not a Myth

There has been an ongoing debate in deer management over the culling young white-tailed bucks based on antler characteristics ever since the first research on the subject concluded. The subject at the very heart of this debate still remains the harvest of spike antlered bucks. Though many deer managers cull bucks in an attempt to improve the antler quality of their deer herd, does it really work?

DADH: “Conflicting penned deer research findings have fueled the age-old culling controversy. Study results on captive deer have produced recommendations ranging from removing all spike-antlered (presumably genetically inferior) yearlings, to complete protection of all yearling bucks regardless of their antler traits. Those favoring selective removal of small-antlered young bucks claim such a practice will remove small-antlered genes from the herd and improve antler quality.”

Texas has lead the way in terms of antler research. Research conducted by Texas Parks and Wildlife Department suggests that breeding better-antlered white-tailed bucks improved the antler quality of bucks sired, but then researchers at Texas A&M University concluded that a doe’s “nurturing ability” was the most important factor. The latter study suggests that the genetics of individual deer are not important at all?

The Culling of White-tailed Bucks is Not a Myth

In an attempt to end the culling debate, researchers from Stephen F. Austin State University set out to determine if a white-tailed buck’s first set of antlers were good predictors of future antler growth. Would yearling bucks in a wild population and varying in antler quality really be significantly different as they aged? To answer this question, wild bucks were captured in South Texas and yearling bucks were permanently marked. This allowed bucks to be tracked from yearling to maturity.

What did they find? Well, at 4 1/2 years old they observed no significant difference in Boone and Crockett antler scores between marked 2, 3, 4, 5, 6, 7, and 8 point yearling bucks. Researchers found that smaller antlered yearling bucks attained a mean antler size equal in width, mass, length and number of points to those starting with larger antlers at yearling age. They were also not significantly different at 5½ years of age and older. Earlier I said that culling works, but this research suggests that removing small-antlered yearling bucks would not improve mature buck antler size. So what gives?

Well, first let’s look at how the yearling bucks were grouped. In the study, yearling bucks were divided into two antler-point categories, those with three or fewer antler points and those with four or more antler points. Although their objectives were to determine if 2 and 3 point bucks were inferior to 4+ point bucks, the implications to deer managers are muddy. If one were to just read through the study it would seem meaningless to cull at all, but it’s not and here’s why.

In my opinion, instead of comparing 2 and 3 point yearling bucks with 4+ point yearling bucks, the data should be re-worked to compare 2 and 3 point yearling bucks with 7 and 8 point yearling bucks. Since most yearlings have either 2, 3, 4, 5, 6, 7, or 8 total points, I think all the mediocre yearlings (4, 5, and 6 points) bring down the average from the top-end deer (7 and 8 points). Since yearling antler points, like everything else, fall along a bell curve, I can only assume that there were many more 4, 5, and 6 point bucks in their sample than 7 and 8 point yearlings. Let’s see the data from 2 and 3 point deer versus only 7 and 8 point yearlings.

Buck Management:  Culling bucks is not simply shooting every 2 and 3 point buck we see. If you are even remotely interested in improving the buck segment of a deer herd then I recommend shooting yearling bucks with 4 or fewer antler points. If you have a higher threshold for pain (especially fewer bucks in the short-term), then I suggest shooting yearling bucks with 5 or fewer antler points. This may sound insane at first, but because top-end bucks make up only 20% or less of the buck herd, the competition has to be removed! By doing this, a land owner can ensure that all future deer (bucks and does) are sired by the best bucks. If you are going to make drastic genetic changes within a population, it takes drastic action. Ranchers do not put a crappy bull, a mediocre bull, and a good bull in with their cows and hope all the calves end up being grand champions.

Buck management is not a one-size-fits-all for every ranch. Culling must occur at the yearling level as well as each age class thereafter. Bucks at each age must be compared on a relative basis to other bucks in the age class and inferior bucks should be harvested. As a property progresses in a deer management program the quality of cull, management, and trophy bucks should increase if the age, genetics, and nutrition are in place. And remember this, if genetics were not heritable why would deer breeders (whether you like them or not) consistently produce monster buck after monster buck. I think there is something to it!