White-tailed deer

Name and taxonomy

The scientific name is Odocoileus virginianus. Zimmermann described the species in 1780 from Virginia, and the state gave the deer one of its older names, the Virginia deer. Hunters in North America simply call it the whitetail. Spanish speakers call it venado cola blanca, and French Canadians call it cerf de Virginie.

It belongs to the deer family, Cervidae, within the even-toed hoofed mammals, Artiodactyla. The genus Odocoileus also holds the mule deer and the black-tailed deer of western North America. Scientists have described 38 subspecies, 17 of them in North America. Genetic work suggests the real number is smaller than the 30 to 40 forms named in the last century. The Key deer of Florida and the Columbian white-tailed deer of Oregon are both listed as endangered in the United States.

Evolution and relatives

Like other New World deer, the white-tailed deer belongs to the subfamily Capreolinae, which also holds moose, reindeer and roe deer. Its closest relatives are the mule deer and the black-tailed deer. The two species meet in the west, and in the Trans-Pecos region of Texas they sometimes produce hybrids. The mule deer and black-tailed deer have lost more than half their numbers since 1960, while the whitetail has recovered.

The species follows Bergmann's rule: deer grow larger with distance from the equator. The northern subspecies of the north-eastern United States and eastern Canada is the largest and darkest. The smallest deer live in the Florida Keys and in the wooded lowlands of the tropics. Andean deer are larger than other tropical forms and carry a thick, slightly woolly coat.

Appearance

The coat is reddish brown in spring and summer and turns grey-brown in autumn and winter. White fur marks a band behind the nose, rings around the eyes and the inside of the ears. The chin, throat and underside of the tail are white too. Older deer tend to have longer snouts and greyer coats. One herd at the former Seneca Army Depot in New York is white all over except for the nose and hooves. The animals are not albinos.

Adults measure 95 to 220 centimetres long, including a tail of 10 to 37 cm. Shoulder height is 53 to 120 cm. Bucks in North America usually weigh 68 to 136 kilograms, and does weigh 40 to 90 kg. A Minnesota buck shot in 1926 was estimated at 232 kg alive, the heaviest on record. Tropical deer average only 35 to 50 kg, and some adult does weigh just 25 kg.

Only the bucks grow antlers, and they regrow them every year. About one doe in 10,000 also grows a set. The antlers start in late spring under a soft skin called velvet and are shed between late December and February. A buck's inside spread runs from 8 to 60 cm. Size and branching depend on food, age and genes, so antlers are a poor guide to a buck's age.

Habitat and range

The white-tailed deer lives from southern Canada across almost all of the United States, apart from the far west. It continues through Mexico and Central America and into the north of South America, reaching Peru and possibly Bolivia. Texas holds more deer than any other state, province or country, with about 5.3 million. Farming beside the Canadian Rockies has let the species spread north-west as far as the Yukon.

The species is a generalist. It prefers the edges between woodland and open ground, where thickets give cover and clearings give food. It also lives on prairie, in oak savanna, in the cactus and thorn scrub of Texas and Mexico, and in the swamps of Florida. In Central and South America it favours dry forest, savanna and riverside woodland and avoids dense wet rainforest. Andean deer live in mountain grassland up to about 13,000 feet.

People have introduced it to New Zealand, the Caribbean and several European countries. Finland received four deer from Minnesota in 1935, and by 2020 the country held about 109,000. GBIF holds records from 44 countries, though that count includes zoos and escapes.

Diet and feeding

The white-tailed deer is a browser first and a grazer second. It eats the shoots, twigs and leaves of woody plants, plus grasses, legumes, acorns, nuts, berries and wildflowers. In eastern forests it takes buds of maple, poplar, aspen and birch, and it turns to conifers in winter. In deserts it eats yucca, prickly pear and tough shrubs. It raids corn, hay, clover, orchards and garden plants wherever it lives near people.

A grown deer eats about 900 kilograms of plant matter a year. It is a ruminant with a four-chambered stomach, so it can digest mushrooms and poison ivy that would harm a person. It swallows food quickly in the open, then chews the cud later in cover. It chews old bones when it needs calcium and has been seen eating nesting songbirds and mice. The deer feeds mainly from before dawn until mid-morning and again from late afternoon to dusk.

Behaviour and social life

The white-tailed deer is active mainly at dawn and dusk and rests in short spells through the day and night. It is the shyest and most nervous of the North American deer. Home ranges are small, often a square kilometre or less. The deer does not migrate, but in deep snow a herd tramples a network of trails called a yard and stays there.

For most of the year the basic group is a doe with her fawns. Does sometimes feed together in larger groups, and herds of hundreds have been seen. Bucks form loose groups of two to four in summer and split up before the rut. During the rut a buck follows one doe at a time and fights rival bucks antler to antler, but he keeps no harem.

A startled deer blows hard through its nose, raises its tail and bounds away with the white underside showing. It has been clocked at 60 kilometres per hour in a sprint and can hold 50 km/h over 5 to 6 km. It can jump 3 metres high and 9 metres forward. It swims well and often crosses lakes and rivers to escape predators or biting insects. A cornered deer may charge and strike with its antlers or hooves.

Communication and senses

Sight, hearing and smell are all sharp, but the deer relies most on its nose to detect danger. Its horizontal pupil gives good night vision, and it notices movement in dim light better than a person does. It sees only two colours, blue and yellow, so it barely notices the bright orange that hunters wear.

Fawns bleat to call their mothers. Adults grunt, snort and, when hurt, give a loud bawl. A mature buck makes a grunt-snort-wheeze that warns rivals off. The alarm blow and the raised white tail alert every deer nearby.

Scent does most of the talking. Glands sit in front of the eyes, on the forehead, between the hooves and on the hind legs. A buck scrapes bare earth with his front hooves, urinates over the tarsal glands on his hocks, and rubs his forehead on the twig above. He also strips bark from small trees with his antlers to make a rub. These sign-posts tell does that he passes this way and tell other bucks who is in the area.

Reproduction and life cycle

The rut runs from October to December, and in the north most does come into heat in November. A doe is receptive for about 24 hours, and if she is not mated she returns to heat about 28 days later. A buck mates with as many does as he can and eats little, so he loses condition through the rut. Most does first breed at about 18 months, though a well-fed fawn can breed at six or seven months.

Pregnancy lasts about 6.5 months, or 198 days. The doe drops one to three spotted fawns in May or June, and a fawn weighs 1.5 to 2.5 kilograms at birth. A first-time mother usually has one fawn, and twins are the rule in later years. For the first four weeks she hides the fawns in cover and returns to nurse them four or five times a day. She eats the fawn's droppings so that no scent gives it away.

Fawns follow their mother at about a month, are weaned at eight to ten weeks and lose their spots by their first winter. Young bucks leave at one year, and young does often stay for two. Most wild deer live only about two to three years, and few pass ten, though the wild record is 20. A captive deer has reached 23 years.

Predators and threats

Wolves, cougars, jaguars and alligators kill adult deer, and people kill more than any of them. Coyotes, bobcats, lynx, black bears and wolverines take mostly fawns, though a bear or a coyote pack can pull down a weak adult in winter. Golden and bald eagles sometimes snatch a fawn. Vultures, foxes, ravens and crows clean up the carcasses.

In the eastern United States most of the large predators are gone, and the coyote is often the only wild hunter left. Grey wolves remain the main cause of death where the two species overlap, in Minnesota, Wisconsin, Michigan and most of Canada. The rich deer population helped the wolves of the Great Lakes recover.

Cars are a major killer. The insurance industry estimated 2.4 million deer collisions in the United States over two years to 2009. Disease matters too. Chronic wasting disease spreads through farmed and wild herds. Biting midges carry haemorrhagic disease in hot summers, and 18 species of tick feed on the deer in the United States alone.

Population and conservation

The IUCN lists the white-tailed deer as Least Concern. It is the most numerous large mammal in North America. By about 1930 unregulated hunting had cut the United States population to about 300,000. Bans on commercial hunting, game laws and the clearing of old forest reversed the decline. By 2005 the United States held about 30 million deer, close to the number before European settlement.

Numbers have fallen by several million since 2000 but were judged healthy in 2017. Two subspecies remain in trouble: the Key deer of Florida and the Columbian white-tailed deer, which the IUCN rates as Near Threatened. In Central and South America many populations are hard to study, overhunted and poorly protected, and some areas have lost their deer.

In much of the east the problem is now too many deer. At about 8 deer per square kilometre browsing starts to strip the forest understorey. Managers use longer hunting seasons, professional sharpshooters, contraception and sterilisation to hold numbers down. Moving deer elsewhere is costly, stresses the animals and can spread chronic wasting disease.

Relationship with humans

The white-tailed deer is probably the most hunted big game animal in the Americas. Native peoples hunted it for meat and turned its hide into buckskin. Today it supports a large hunting industry, and Pennsylvania, New York, Wisconsin and Ohio have the densest concentrations of hunters. Deer farms sell venison, velvet antler, hides and breeding stock, and hunting ranches sell guided hunts.

The costs are large. Deer ate about 765 million dollars of crops, nuts, fruit and vegetables in 2001. Collisions with vehicles caused about 300 human deaths over two years to 2009 and more than 7 billion dollars of damage. The deer is the main host of the adult black-legged tick, which carries Lyme disease. Where deer are dense, Lyme disease cases rise, though the deer itself does not catch the bacterium.

In 2021 researchers found antibodies to SARS-CoV-2 in 40 percent of sampled deer. People passed the virus to deer at least six times, and one Ontario deer may have passed a new variant back to a person. Deer also carry the brainworm parasite, which does them little harm but kills moose.

In culture and myth

The white-tailed deer is the state animal of ten American states, from Arkansas to South Carolina. Honduras and Costa Rica both name it their national animal, and it appears on the Costa Rican 1,000 colón note. A buck's head tops the coat of arms and the flag of Vermont. The Milwaukee Bucks basketball team took its name from the animal. Disney's 1942 film Bambi turned the roe deer of the novel into a white-tailed deer.

In Cherokee tradition, Awi Usdi, the Little Deer, punishes a hunter who kills without asking pardon. In Huichol tradition, the deer stands for maize that feeds the body and peyote that feeds the spirit. Huichol ceremonies still honour a maize deer and a peyote deer. The Cherokee, Creek, Ojibwe, Navajo, Zuni and several Pueblo peoples have deer clans. The Ojibwe name for the animal, waawaashkeshi, is also the name of the clan.

In Tlingit tradition, the deer stands for peace and for the ambassador. Among the Tupi-Guarani of Brazil, Anhanga is a red-eyed white deer that protects the animals of the forest. Mesoamerican hunters still ask their gods for permission before a deer hunt, and some rites take place in caves. Across the continent the deer is thought to stand for fertility and for the people themselves.