What is the Whitetail Deer
(Evolution, diet, deer management, growth rates, death, nutrition of, breeding, annual cycle of whitetail deer.)
The white-tailed deer, Odocoileus virginianus, is the most elusive big game animal in North America. The species numbers upwards of twenty five million animals within the continental United States. The whitetail’s survival success is solely dependent upon its adaptability. These animals are currently thriving in almost every imaginable type of terrain in America, including swamps, prairies, mountains, semi-arid regions, and big timber.
No other species of big game animal has drawn such mass popularity. Whitetail have evoked a great passion and interest, and have become the primary outdoor topic for the majority of today’s outdoor books, magazine articles, and video hunts.
Early pioneers and Native American cultures were dependent upon the whitetail deer. Estimates suggest about 20-25 million whitetails resided in the continental United States in 1492. The animal was seen as an unexhaustable source of food. The population of the herd had been significantly decreased by the 1700’s due to market hunting and habitat destruction. Many species of animals became extinct because of the aforementioned acts, however the whitetail adapted. During the early 1800’s most pioneers and Native Americans were using rifles and muskets as opposed to primitive weapons, such as bows, spears, etc. Prior to firearms, it is believed the whitetails which were harvested were mostly mature animals. A decline in age structure began as a result of the introduction of the firearm. Early America began to decrease the whitetail herd dramatically as it had been with the bison. By the early 1900’s, the herd had been drastically reduced from 20-25 million to one half million animals. A devastating 98% reduction. During the mid 1900’s, serious scientific investigations began to reveal the clues which surround whitetail deer biology. Passage of the Pittman-Robertson Act in 1937 channeled the sportsman’s dollars into wildlife research and management, and the pace of these investigations increased. A decline in age structure began as a result of the introduction of the firearm. The first whitetail deer season occurred, in 1945, near Halsey, Nebraska. Two whitetails were taken. It wasn’t until 1961, sixteen years later, that the enire state was opened to firearm hunters. That year 1,400 animals were taken. During the 1960’s, John Ozoga published his first scientific paper on whitetail deer biology and management (Whitetail Autumn, 1994).
Although the whitetail suffered from man’s invasion into the environment, they experienced benefits from the intrusion, as well. Dr. James C. Kroll, 1996, states, “Interestingly enough, my observations suggest a form of “unnatural” selection resulted from this slaughter. Deer escaping harvest were those who did not behave in normal whitetail fashion. They were more secretive, more nocturnal, and more flighty than their ancestors. The result is an animal much more dificult to kill. The King Ranch of Texas probably has the sole remaining pristine herd. These deer-even mature bucks-will allow the hunter to approach within forty yards. Why? That’s the flight distance developed to avoid the close range shots needed by aboriginal man with his primitive bows. The King Ranch experienced little hunting pressure at least into the early 1900’s (Pope and Young Club, 1996). Modern man had forced adaptation of this elusive big game animal, the whitetail deer.
The white-tailed deer is named for its most distinctive feature, the large white tail or “flag”. That “flag” is often all a hunter sees as the animal bounds away through the tall grass or darkened timber. The color of the deer’s upper body and sides change with the season, from reddish-brown in summer to gray in winter. The belly and the underside of the tail are white, with a white patch on the throat. The deer sheds coat twice a year. The heavy winter coat gives way to a lighter one in spring, which is replaced in early fall. The fawn’s coat is similar to the adult’s but has a multitude of white spots which usually disappear at four of five months of age. Fawns are born in late spring and summer. By early November, male fawns weigh around 85 pounds, a female about 75 pounds. Yearling bucks average 150 pounds, while does of the same age average about 20 percent less, or 120 pounds. Some older bucks weigh upwards of 250 pounds.
A buck fawn has bumps on his skull where antlers will grow when he is older. Yearling bucks may have one to six points on each antler. Based on a study of over 2,000 deer checked in during the 1990 season, yearlings average six points on both antlers. The same study has shown approximately 20 % of the yearling bucks have four points on each antler, 19 % have three points on each antler, and about 6 % have spikes instead of fully-developed antlers (Nebraska Department of Natural Resources, 1998).
Nutrition plays the most significant role in the development of both antlers and in maintaining body weight. The whitetail deer possesses a four chamber stomach. Chamber one, the rumen, is the largest and used to store food for future chew and nutrition production. The rumen allows the species to gather food. Chamber two, the reticulum, shares the responsibility of nutrient production with the rumen to provide energy for the animal. After energy production occurs, the discarded materials pass into chamber three, the omasum, and then to chamber four, the abomasum. Food digestion takes from two hours to six days, dependent upon what the food source was. For fawns the stomach is fully developed at 12 weeks, the approximate time of weaning.
A whitetail’s diet should include quality proteins, carbohydrates, sugars, fats, minerals, and vitamins to avoid malnutrition. Agricultural crops constitute from 40 to more than 50 % of the whitetail’s diet in some areas. In northeast Kansas, corn is the most sought after food in all seasons, except summer, as approximately 29 % of the diet Kansas DNR, 1998). Corn comprises approxiately 40 % of the deer’s diet in Iowa (Iowa DNR, 1998). Although whitetails are commonly observed in alfalfa fields, alfalfa is a relatively minor food source. Native foods that make up part of the deer’s diet include woody vegetation, particularly buckbrush and rose, with lesser amounts of dogwood, chokecherry, plum, red cedar, pine, and a host of other species. Forbs, particularly sunflowers, are important, while grasses and sedges are used only briefly in spring and fall. Although whitetails can obviously exist entirely on native foods, they apparently have a preference for farm crops. Crop damage by whitetails constitues the biggest management problem in agricultural states as they must balance deer numbers to satisfy both hunter demand and landowner tolerance.
Whitetails seldom die of starvation. Death by malnutrition is more common. Malnutrition is dependent upon the deer’s sex, age, reproductive status, and health. These factors are effected by season and climate. Lack of a certain vitamin or protein may occur when the herd eliminates an areas primary food source due to overgrazing. Overuse of a foodsource by the herd results in unhealthy deer. This is why overpopulation can be the herd’s demise. The best deer habitat is one which provides a variety of food sources.
Good nutrition is of paramount importance to the whitetail deer. It is especially important to fawn survival. Fawns need to be born in spring and partake of good nutrition throughout the summer months to maximize their odds of storing fat and surviving the coming winter.
Nutrition plays a large part in determining antler growth. When a buck is unable to consume the necessary amounts of high quality forage, antler growth is minimized. “Researchers at Mississippi State University puchased a nine year old buck that had been fed a low-protein, corn only diet. The deer had relatively small, eight point antlers with a narrow seventeen inch spread. The old deer was given a sixteen percent protein diet and bingo! It’s next rack sported twenty one points and a twenty seven inch spread. Not bad considering the animal was past its prime.” 3 States such as Illinois, Iowa, Missouri, and Nebraska have boasted of large-racked deer for many years. A major part of the success of those states is due to the large quantities of agricultural crops, which are available in the areas of whitetail herds. Nutrition also determines the deers general health and likelihood of survival.
Prior to the whitetail breeding season adults live in groups of like sexes. The two sexes also seem to prefer different types of bed areas. Bucks tend to stay closer to dense cover, while does are not as selective.
The female social unit contains several generations of mothers and daughters who have shared the same core area throughout life. Young antlerless bucks, button bucks, are also included in this group prior to breeding season. During the rut, those antlerless bucks are driven from their home group, and sometimes the home range, which prevents inferior breeding. The oldest doe usually assumes the lead role in the unit. This natural hierarchy maximizes the reproduction ability to maintain the herd.
Prior to the breeding season, bucks travel in a social units also. These units are commonly referred to as “The bachelor groups”. These groups are very competitive in that they serve to determine dominance roles. Dominance determination is nessecary because all male deer compete for breeding rights to receptive does. Dominance is determined by physical size, antler size, strength, experience, fighting ability, and tempermant. Deer with average racks may dominate “trophy” bucks solely upon tempermant. Mean dispositions can often be profitable for young bucks out in the whitetail world.
Bucks and does vary in size, shape, growth and metabolic rates, food preference, cover preference, as well as many other aspects of physiology and biochemistry.
Cover preferences results from the instinctual motivation of each sex. Does chose a habitat which is most condusive for bearing offspring. Doe cover includes accessability to diversified food selections, and cover for hiding fawns. Bucks chose habitat where nutritional resources are excellent. Bucks also favor dense cover for hiding purposes as they tend to be more elusive.
After several months of sexual segregation during fawn rearing months, whitetails begin to intermingle in late summer and early autumn once again. This time period alters deer travel patterns, food sources, and brings about the most interesting aspects of the whitetail’s life cycle.
During this period, velvet covered antlers begin to harden. The old mature bucks are usually the first to shed antler velvet. In northern states, bucks complete this task by late August. This task isn’t completed until late September in southern states. Mineralization of the antlers is triggered by rising levels of testosterone. In other words, the more robust the animal, the quicker the process occurs. Bucks which don’t produce the nessecary testosterone levels, due to testicle injury, or sickness will not shed velvet.
The late summer and early autumn months serve the purpose of establishing deer rank in the social system. These ranks occur within the social units of both does and bucks. These social ranks are in no manner a permanant placement. Ranks are continually challenged by whitetails within that area’s herd, as well as by roaming whitetails from nearby areas. Ranks changes may also occur as a result of death, disease, new additions to the herd, and other factors.
Social ranks are challenged, and do change. Breeding rights are the reward for the highest ranking whitetail bucks in the herd.
Offspring usually establish home ranges which are the same as their mothers. Yearling females continue to reside within that area, however the yearling bucks do not. At about one year of age, bucks are confronted in an aggressive manner by their mothers in an attempt to encourage dispersal. Initially the aggressive advances manifest themselves in body posture and visual contact. If the offspring does not disperse from the area as a result of the less aggressive mannerisms, attacks are sure to follow. As a result, approxiametly 80% of all yearling bucks disperse. The objective of this instinctual behavior serves to prevent inbreeding.
Genetics play a major role in antler development. Although life span and nutrition is also of paramount importance, bucks need genetic potential to reach maximum growth. Genetics ultimately determine the shape, size, and length of tines as well as the entire rack in general. Deer of specific areas carry a general rack shape or unique characteristic due to the gentics of the particular “family” of deer, through several generations of animals. In Ohio, Michigan, and Illinois I typically view racks possessing multiple points, tall tines, and impressive width. Alabama racks are usually not as wide but are commonly tall. Texas racks seem to be darker in pigment, wide, and tall, but lacking the mass midwestern deer offer.
A low buck to doe ratio offers dominant bucks the opportunity to breed with more does which in turn produces higher quality racks. When buck to doe ratios are unproportionally high, dominant bucks are unable to service a high number of does. This means inferior bucks are able to service more does which produces low quality racks.
With good health and good nutrition, whitetailed deer are prolific breeders. Examination of 600 does has shown about 60 percent breed as fawns, about six months old, and virtually all of the older deer produce young. At least a portion of the buck fawns are capable of reproduction. Breeding commences in mid October and peaks in mid-to-late November for adults, and about one month later for fawns. A buck may mate with several does,up to 20 have been recorded under “pen” conditions. Fawns are born after a gestation period of about 201 days, from early May through late September, with about 60 percent of the total born in June.
Does bred, when less than a year of age normally produce a single fawn, with about 10 percent rearing twins. Of the older does approxiametly 67 percent have twins, 21 percent have single fawns, and 12 percent have triplets. About 140 fawns are born for every 100 does in the population.
The whitetail’s reproductive rate is quite high when compared to the mule deer’s, which is about 94 fawns per 100 does per year. Only about seven percent of mule deer does breed as fawns. A year later, 94 percent of whitetails and only 68 percent of mule deer become pregnant as yearlings. About 79 percent of pregnant whitetail does carry twins or triplets, while only 52 percent of pregnant mule deer does have multiple births.
At birth, a female fawn weighs about 5 1/2 pounds, males about 7 1/2 pounds. A fawn is capable of walking shortly after birth, but its movement is limited during the first few days. When the fawn is two or three weeks old, it begins eating vegetation in addition to nursing. A fawn is normally weaned when it is about four months old, but is capable of surviving without milk at three onths or less. About 30 percent of the fawns do not survive until fall.
Whitetails regularly establish dominance and superiority in determining who obtains access to food, cover, bedding sites, fawn raising spaces, and breeding. Dominance is established through physical confrontation on a regular basis. True aggressivity is rarely practiced to avoid injury. Threats and displays of aggression without contact are practiced most often.
It is believed that although sparring is primarily utilized to determine dominance, sparring may not always be a decisive contest. Sparring is used to determine the opponents antler configuration for future fights as well as to gain knowledge of an opposing buck’s fighting skills. More often, when sparring is done in a non-decisive manner it is done for social interaction and recreation. Any experienced hunter can testify to watching deer, especially yearlings, run and play for entertainment purposes. In the same respect, during the late summer months, bucks often spar for recreational purposes. Sometimes recreational sparring can turn into an aggressive battle depending on the tempermant of the animals which are engaged. True fights between bucks usually occur only between two evenly matched animals during the rut.
Does engage in both recreational and dominance determination battles. Does are more apt to battle over food and fawn rearing cover. Does may begin the battle with direct eye contact, aggressive body language, or posture. If dominance cannot be determined by the less aggressive modes of communication a battle will ensue. Many does rise to their hind legs in an upright position and box like prizefighters to establish dominance. Hoof slapping from mature does can be a painful experience. In 1992 a member of a hunting party I am familiar with arrowed a mature doe. The hunting party assisted the fellow in the tracking of the animal. Upon discovering the whereabouts of the near fatally wounded animal this fellow decided he would save his arrows and finish the harvest manually with a hunting knife, against the advice of the hunting party. The contest ended with the deer being the victor. The hunter suffered bruises and lacerations. Although I didn’t witness the event I will assure you this fine fellow will refrain from attempting this feat again.
Ten million people in the United States alone hunt whitetails each year. Deer hunting is enjoyed as a recreational activity on a personal level. On a public level, the next century will expose deerhunting is big business. As a group, deerhunters may look forward to a bright future with state of the art equipment. Hunting generates more revenue across the board than any other sport in North America, including baseball, football, hockey, or basketball. For the whitetail herd to meet hunter expectations, our sportsmen must form highly structured organizations to raise funds to benefit the species. Possibly as Ducks Unlimited has done for waterfowl.
Successful deer management programs are beginning to be implemented by private landowners as well as state departments. It was once thought that archers were insignificant in controlling overpopulation problems of the herd. The program at Clinton Lake, Illinois mandates hunters to harvest a doe prior to tagging an antlered buck. This practice has been proven to be quite effective with reducing overpopulation problems, which result in death, disease, and inferiority of the species. It doesn’t take a rocket scientist to implement a deer management program. When in doubt.......kill does.
Some state departments, such as those found in Illinois, Michigan, Iowa, Minnesota, and Ohio, have implemented deer management programs which promote quality buck production. These programs and weapon mandates, such as “shotgun only”, and tag lotteries, have been quite effective in herd management as well. Other states are less focused on herd management programs that promote trophy bucks. Missouri currently offers a second four day firearm season, after the initial eleven day firearm hunt. The late second season hunt occuring in January is devised to offer a doe only harvest. The problem with this misconception is twofold. Bucks that have already shed antlers are being legally harvested as does. The second season takes place almost two months after the herd has been desperately raping the countryside of the few available foodsources that remain. If the second season was scheduled earlier, the herd would have more food available to those deer which survive the firearm season. As mentioned earlier in the text, a lack of nutrition is solely responsible for malnutrition which gives way to disease. Disease can devastate a herd of whitetails. States which don’t manage for quality lose literally millions of dollars annually to hunters who go elsewhere to pursue quality bucks. “In Nebraska deer hunters spent about 1.5 million for hunting permits alone in 1990. The total amount spent on whitetail hunting and assocaited activities in Nebraska alone is near ten million dollars annually.” 4
1 Whitetail Autumn, Seasons of the Whitetail Deer, Book One, Willow Creek Press, Minocqua, Wisconsin, 1994, page 14
2 Bowhunting Records of North American Whitetail Deer, 1st Edition, Pope and Young Club, 1996, page 17
3 Dr. James C. Kroll, Bowhunting Records of North American Whitetail Deer, 1st Edition, Pope and Young Club, 1996, page 17
4 Nebraska State Department of Natural Resources, 1999