White-tailed Deer (Odocoileus virginianus) are mammals belonging to the order Artiodactyla (ART-ee-oh-DACK-tuh-luh, meaning even-toed animals) and the family Cervidae (SER-vuh-dee), which includes Moose, Elk and reindeer (which are known as Caribou in North America), among others. The White-tailed Deer’s genus is Odocoileus, a word that comes from Greek for “hollow tooth.” “Deer” is from the Old English dor, meaning “beast.” Like “Moose” and “sheep,” deer is both singular and plural.
White-tailed Deer are native to the Americas and are the most widely distributed hoofed animals in the Western Hemisphere. They number around 30 million in the United States and inhabit all states but Utah, Nevada and California. They’re most heavily represented east of the Rocky Mountains. They have no close relatives anywhere else in the world.
White-tailed Deer evolved over millennia from small, antler-less, tropical herbivores to the animals we see today. Scientists have compared fossil records against DNA-dating and have established that White-tailed Deer date back to the mid-Pliocene Epoch. That was between 5.33 and 1.81 million years ago — a time of global cooling which led to the spread of grasslands and, in turn, created suitable deer habitat.
The deer began to radiate northward from the tropics of Central America and South America, and by the Pleistocene Epoch (1.8 million to 10,000 years ago) they were common in eastern and central North America. White-tailed Deer now inhabit localized areas of Europe, having been introduced there in the mid-1800s.
The White-tailed Deer population has fluctuated due to human activities. Heavy trading by early settlers and American Indians reduced the number of deer. Then over-hunting for meat and sport dropped this country’s deer population in the 1800s to about 500,000. In some areas, White-tailed Deer disappeared altogether.
The downward trend was steady until 1900 when a federal wildlife law, the Lacey Act, was enacted to prohibit interstate trafficking of wild game. That was followed within a few years by new laws in most states that further benefited the deer, and their population began to increase steadily. The deer also benefited from the clear-cutting of forests to make way for farming and urban development. That allowed vegetation favored by deer to emerge, and it continues to this day — the more we clear, the more deer habitat we create. Today, humans and deer are increasingly living side-by-side, even in urban areas.
There are numerous subspecies of White-tailed Deer, but taxonomists don’t agree on just how many. Depending on the source, there are somewhere between 30 and 40. Most subspecies are named for the region they populate. For instance: the Florida Key Deer, the Dakota White-tailed, the Kansas White-tailed and even a Hilton Head Island White-tailed Deer. This naming pattern holds true for most of the subspecies in Mexico and South America, too, with such species as the Rain Forest White-tailed (southern Mexico) and the Northern Vera Cruz White-tailed Deeer.
Male White-tailed Deer are called bucks and females are does (DOZE). You may know the term “stag” for male deer, and that isn’t incorrect, but it’s more commonly used for larger members of the Cervidae family, like male Moose or Caribou.
If you’ve never seen a White-tailed Deer “in person,” you’ll probably be surprised when you do. They’re small! The shoulder height of an adult White-tailed Deer is about the height of a typical 5-year-old child — about 32 to 40 inches (0.76 to 1.01 m), with males being taller than females. Their body length runs 52 to 95 inches (1.32 to 2.41 m). As for weight, occasionally a male might weigh up to 350 pounds (158.8 kg), but typically they weigh no more than about 150 pounds (68 kg). Females weigh around 90 to 100 pounds (40.8 to 45.4 kg) — by comparison, German Shepherd dogs weigh up to 100 pounds, and a female English Mastiff can weigh between 120 and 200 pounds (54.4 and 90.7 kg). White-tailed Deer living in cooler climates tend to be larger than those living in warmer climates.
White-tailed Deer get their name from their tail, which is fringed with white and has a white underside. This is barely seen unless the deer is running or disturbed, at which point the bushy tail flips up and curls forward, exposing the white hair. The tail is around 10 inches long (25.4 cm).
In summer, the White-tail’s hair is reddish-brown and relatively short, with a thin, wiry texture. It dulls to grayish in winter, with long guard hairs and a thick undercoat to provide insulation. The hair of White-tailed Deer that live in northern regions has hollow shafts which fill with air and add to it’s insulative value.
A unique subspecies of white-haired (not albino) White-tailed Deer live on protected grounds of the former Seneca Army Depot in Romulus, New York.
White-tailed Deer have excellent senses: Their vision is sharp, with superb peripheral sight — because their eyes are located at the sides of their head, they can see almost all the way around their body. Also, their eyes have more light-detecting cells than humans have, which give them excellent night vision. Acute as their vision is, smells and sounds carried in air currents can alert them to danger long before their eyes do. Reportedly they can detect smells 10,000 times better than a human can. And, their large, upright ears, 5 to 12 inches long (12.7 to 30.6 cm), can capture the softest sounds.
White-tailed Deer have 32 teeth, but no front teeth in their upper jaw. In their place is a tough pad that’s used to help the lower front teeth hold food in place.
Their legs are long and slender with powerful muscles that are perfectly designed to escape predators. The front legs provide swift turning and pivoting ability. The back legs offer strength for leaping and speed — they can propel a deer 10 feet high (3 m) or 30 feet forward (9.1 m) in a single bound, and gallop at 35 miles per hour (56.4 kph). The deer are also exceptional swimmers — up to 13 miles per hour (20.92 kph). Their power and agility make them a challenge for predators (for gardeners, too — if White-tailed Deer see something yummy inside a garden fence, well, over it they go.)
Deer feet are “cloven” hooves, meaning they’re split into two toes, which bear the weight of the animal. They also have two other toes located higher up on the leg. Called dewclaws, they’re similar in structure to the hooves, but smaller, and don’t touch the ground, except when the deer runs, jumps or is on soft ground. The outer surface of the hoof is called the hoof wall or horn; it’s hard and made of keratin, the same protein that forms our fingernails.
It’s commonly assumed that “antler” and “horn” are two names for the same thing, but there’s a difference. Antlers come in pairs; they’re branched and protrude from the front of the deer’s skull. Horns also protrude from the front of the skull, but they’re permanent and don’t branch.
Antlers are grown each spring and are temporary. Growth begins as longer days trigger an increase in the male’s testosterone level. First, two bumps on his forehead, one a few inches above each eye, react to the hormone by forming a “bud” from which the antlers will grow. Called pedicle, they’re covered with skin and hair and made of spongy bone. (Male fawns begin to grow them at only a couple of months old.)
Within a month the first tine (or point) begins to form. A month later, a second tine starts forming. Antlers grow fast — up to 2 inches or more per week — and in about four months they’re fully developed.
Each antler has a main beam that first grows slightly in a backward direction, then reverses and curves forward and over the face. Each main beam holds from one to several un-branched tines. Antler width (or spread) for the White-tail is calculated by the greatest inside spread between the main beams. Spread may range anywhere from 3 to 25 inches (7.6 to 63.5 cm). Antlers are usually symmetrical, but asymmetrical pairs also occur, with tines growing in every direction.
While antlers are growing, they’re soft to the touch and covered in “velvet,” a skin tissue filled with a rich supply of blood vessels and nerves. By late summer, however, decreasing day length signals the testosterone level to drop, and the blood supply turns off. The velvet, now starved of blood, dries up and falls off, often in just a day or two. Males rub their antlers against trees during this time, which clears off the velvet and, incidentally, polishes their antlers to a rich shine.
Males use their now-hardened antlers for combat displays of strength and dominance over one another during the breeding season. The sound of antlers colliding can often be heard over long distances, and it sometimes attracts females in heat. After breeding season ends, antlers drop off, or “shed.” That leaves an open wound, but it covers over with skin. Come next spring, the process starts all over again.
Cast-off antlers are rarely found in nature. They’re rich in nutrients and other animals gnaw up right away. Interestingly, if the tissue that gives growth to antlers is surgically removed from a male’s head and grafted onto another part of his body, a tiny antler will grow there.
The older a buck, the larger his antlers. At 1-1/2 years of age, they average four tines, while at 3-1/2 years and older, they average eight tines. After about 7-1/2 years the antler size declines. It seems like this would be an excellent way to judge an individual buck’s general age. But, not so, say the experts — genes and injury influence antler growth, as do any nutritional deficiencies in calcium, protein, phosphorus or other vitamins.
So, what do the experts do? They check the teeth. It so happens that fawns have baby teeth, just like humans do — they’re born with four, and in a few months will grow baby incisors and premolars. At around 18 months the baby teeth will have been replaced with adult teeth, which are permanent. After that, amount of wear on the molars is used to establish the animal’s age — teeth lose about 0.04-inch of height (1 mm) above the gum line each year.
White-tailed Deer are herbivores and ruminants. Plants of various kinds are their only food after they’re weaned from their mothers. They have a stomach with four chambers specifically designed to undertake the tough demands of a high-cellulose diet. “Ruminant” is a word derived from Latin for “to chew the cud,” which describes what happens to the food they eat.
The first two chambers of the stomach are the rumen (ROO-men) and reticulum (ruh-TIC-u-lum). They perform the same function and are collectively called the reticulorumen (ruh-TIC-u-low-ROO-men). After food is partly chewed and swallowed, it passes back and forth in the reticulorumen, mixing with saliva and breaking down into solids and liquids. The solid material clumps together and is regurgitated. Deer slowly re-chew (ruminate) the material (the cud) to mix it with more saliva and break it down into even smaller particles. Depending on how much fiber is in the food, they may spend several hours a day chewing their cud.
Once swallowed again, the cud passes through the reticulorumen into the omasum (oh-MAY-sum), where many of the mineral elements are absorbed into the bloodstream. From there the mixture moves into the abomasum (AB-oh-MACE-um), which is equivalent to a human stomach, and from there into the small intestine. All four chambers contain vast populations of various bacteria and other microbes which break down and ferment the food material.
White-tailed Deer, being prey animals, are shy and always on alert. They may be active to some extent at all times, but primarily move about in the hours near dawn and dusk, when they can’t easily be seen. They reduce their exposure to danger by leaving their cover only briefly — for instance, to quickly eat and then move back into hiding. During hunting season they may become entirely nocturnal.
During breeding season, roughly late-September through January, males shed some of their hyper-wariness and leave heavy cover to seek out mates. Hunting season is timed so hunters can take advantage of that.
White-tailed Deer live in social groups consisting of an adult female, her fawns and her yearling female offspring. They usually remain together until fall, at which time the yearling males separate from their mother and sisters as breeding season approaches.
White-tailed Deer rest in “deer beds,” which are oval depressions in leaves, soft dirt or grasses. The beds are always surrounded by shrubs and grasses to shield the deer from prying eyes and lousy weather. They rarely bed in the same spot twice, a tactic that probably protects them from predators.
White-tailed Deer have several ways of communicating with each other. For example, males use their antlers to strip the bark off of small trees; this marks their territory. The mark is called a “rub.” They also make scrape lines in their territory by using their front hooves to expose bare ground.
They vocalize, too. Not a lot, but 13 different calls have been identified. For example, one particular call is used by females to locate other members of their family group. Mothers have a call for their fawns. Females have a call that announces when they’re ready to mate. Bucks have several different calls, too. Listen to deer sounds.
Another method of communication is with scent glands. The glands are located between the two parts of each hoof, on the outside of each hind leg, on the inside of each hind leg at the hock, between the eyes and at the base of each antler. Deer leave a scent every time they rub trees or shrubs. Scents alert females when males are moving through their area during breeding season. Scents also let males know when challengers are in the area. The scent glands between the hooves emit a substance with an offensive odor, so with every step a White-tail takes, a scent is left on the ground. Scent also serves as a danger-alert: The deer stomp their feet when they’re alarmed, which leaves an excessive amount of scent as a warning to others.
Breeding season seems to be timed to occur about six and a half months prior to the best fawning period for a particular locale. Commonly called rutting season or “the rut” by hunters, it runs when females are in estrus and males have high testosterone levels, which is anytime from late-September through January.
Males spar with each other to win the rank of top deer. The reward is the first choice of females. Sparring consists of ramming into each other, clicking antlers, trying to push each other backward, kicking and flailing their legs.
A male will chase a female for several days prior to mating, then mate with her several times. He remains with her for several days more to keep other bucks away. When they part company, the buck will go on to mate with several different females before the breeding season ends. He won’t be involved with females again until the next mating season.
The gestation period is about 200 days. A healthy female might mate when she’s as young as seven months old. Females usually give birth to only one fawn the first time. After that, they usually have twins or, sometimes, triplets. The fawns are born quickly, sometimes with the mother standing.
Newborns weigh 5 to 8 pounds (2.27 to 3.63 kg) and wear a reddish-brown coat with white spots. Their eyes are open and they can stand and walk within an hour or two. They nurse almost immediately. This first nursing provides a high-protein milk called colostrum, which contains an assortment of antibodies that will help the fawns resist disease until their own immune system is developed.
A mother stays away from her fawns, hiding them in dense vegetation to protect them from predators. She returns only two or three times a day to nurse them. While they wait, fawns tuck their legs, head and neck into their body for maximum concealment. They lie completely motionless when a predator is nearby. Their coat is a perfect camouflage in the dappled sunlight striking a forest floor. Even if out in the open, it’s hard for predators to see them, and they can’t smell them, either: Fawns have no body odor and hold their urine and feces until their mother returns. When she does, she ingests whatever the fawns eliminate in order to remove any tell-tale odors.
Fawns munch on vegetation as early as a week or so old. At about one month, they start accompanying their mother. Should a predator approach a fawn, its mother will show herself and run off in another direction, hoping to lure it away. Fawns are playful and spend their time frolicking, nudging, jumping and boxing one another with their legs and feet. They’re weaned at eight to 12 weeks. They’ll sport their distinctive white spots for three or four months until their winter coat grows in.
The family stays together until the next spring when the mother leaves her fawns and returns to her favorite birthing area to breed. All of her female offspring will remain in the same general area as their mother throughout their lives. Males, on the other hand, leave their mother in the fall, or certainly by the next spring — if they don’t, the females will force them to leave. Males might have to travel long distances to find new territories.
Life expectancy is up to 10 years in the wild, but males typically live no more than two or three years and females five to six years. In captivity, White-tailed Deer can live up to 20 years.
The perfect habitat for a White-tailed Deer is an area of one or two miles composed of a mixture of trees, shrubs, vines, flowering plants, grasses and other plants, such as fungi. They need water, too, of course. That’s the ideal, but White-tailed Deer are highly adaptable and manage to survive, even thrive, in many different environments, including forests, farmland, brushy areas, even shrubby deserts and from sea level to mountain ranges.
In agricultural areas, White-tailed Deer stay within a forested area until evening, then move out to feed in the fields. On the Plains, which are wide-open and scantily dotted with areas of cover, White-tailed Deer travel along grassy gullies and draws that offer them some cover.
Some White-tailed Deer live year-round in swamps, which provide them with water, many species of trees that drop nuts or offer good wood for browsing, and soft bedding and cover for hiding. In some areas, during hunting season White-tailed Deer head for boggy swamp areas that are inaccessible to hunters.
In summer, the deer like fields and meadows, and seek shade on hot days in deciduous and coniferous forests. In winter, the forests offer some protection from harsh weather.
All a White-tail needs for an encouragement to become a city resident is a park or neighborhood with 20 acres or more of habitat offering them food, water, shelter and cover.
White-tailed Deer are herbivores, and their diet is based on the plants available to them. In a forest, they might feed on undergrowth and fungi. In agricultural areas, they eat such crops as corn and alfalfa, while in the city their diet might consist of shrubs, fruits, nuts, vegetables and flowering plants. Soft-stemmed, broad-leaved, flowering plants (forbs) are their favorites and, given a choice, they’ll pick these over most woody plants and grasses every time. That’s because forbs are more easily digested, providing their body with more available protein. In some tropical and subtropical areas, White-tailed Deer survive without eating any woody plants.
White-tailed Deer are very alert to everything going on around them. They’re agile and fast. They often enter streams and lakes to escape predators. But life is perilous, particularly for fawns. It’s estimated that the number of fawns lost from all causes runs 40 to 50 percent. Predators of fawns and adult White-tails include coyotes, mountain lions, bobcats, wolves and wild dogs.
Humans are the main predator of adult deer — hunters kill an estimated six million a year and injure about twice that number. In some states, hunters take up to 80 percent of the antlered deer each year. Motor vehicles annually kill almost two million more.
*Top photo: White-tailed buck and doe. (Larry Smith / Flickr; cc by 2.0)