Deer

Deer first appeared in Asia about 38 million years ago. Today, they are found throughout the Americas, Europe, Asia and North Africa. These hoofed mammals are usually characterized by bony, often branching antlers that are shed and regenerated annually. They range in size from the impressive European elk, (also called moose) which may be as tall as 7.7 feet at the shoulder, to the tiny South American Pudu, which is the size of a medium dog – about 10 inches at the shoulder. Whitetail deer, the most common species in America, measure between 3 and 3 ½ feet at the shoulder. Males weigh as much as 400 pounds; females weigh 70 – 200 pounds.

Whitetails are known for their tined antlers and flag-like tail with its prominent white underside. The color of its upper body and sides changes with the seasons, from reddish-brown in summer to buff or gray in winter. The belly and underside of the tail are completely white, and there is a white patch on the throat. Deer shed their hair twice a year; in spring, a heavy winter coat gives way to a lighter one that is replaced again in early fall.

Deer eat woody vegetation as well as leaves, grass, buds, berries, bark, wild grapes, apples, sunflowers and acorns. Croplands are a reliable year-round food source, and provide cover from July until harvest, when deer retreat to permanent cover for protection from weather and predators. In some areas, more than 50% of the whitetail’s year-round food comes from crops.

Habits & Habitat

Deer are most plentiful in mixed wooded and open land; they also live in swamps, on mountains, and northern tundra regions. In many areas, the best deer habitat is along streams, where deciduous trees provide woody cover. Grasslands and marshy vegetation are also suitable if the topography provides concealment. Former crop-producing lands that are under long-term retirement have increased whitetail distribution in recent years.

Deer Facts & Features

If cover and food are ample, a deer may live its entire life and die within 1 – 2 square miles of its birth.
Deer move the greatest distances in spring and fall, searching for breeding and/or fawning sites.
Life span in the wild is 16 ½ years.
Adult females move less than other deer.
Yearlings, on their own for the first time, travel the greatest distances.
The whitetail deer is the most important big game animal in North America.
The annual harvest, mostly through hunting, of whitetails exceeds 300,000 in several states.
Whitetails avoid predators by depending on scent as well as excellent hearing and sight.
The whitetail’s lithe, compact body and long powerful legs are well suited for rugged terrain.
Deer are excellent swimmers.
Deer are ruminants (or cud chewers), and have a four-chambered stomach.
Whitetail deer feed most actively at twilight.
Males are known as bucks and are generally solitary.
Females are called does and may travel in small groups, especially with babies (fawns).
In winter, deer often herd for warmth.
Males and females do not normally associate until mating season in the fall.
Except for the musk species, all deer have a liver without a gallbladder.
In the United States, deer have few natural predators and are overabundant in many areas.
They often over-browse their territory and die of starvation, especially in deep snow.
Deer are very adaptable to humans as well as urban and suburban construction.
Automobiles kill thousands of deer annually.

Parenthood

Healthy whitetail deer are prolific breeders. At least half of all female fawns breed by age 6 months. Breeding begins in mid-October; it peaks in mid-to-late November for adults, and about one month later for fawns. Bucks mate with several does each year, with as many as 20 having been noted under pen conditions. After a gestation period of about 201 days, fawns are born from early May through late September with about 60% of the total born in June. Virtually all adult deer produce young, generally a single fawn in a year. About 10% produce twins. When does are older, the bearing of twins increases to 67%; 21% have single fawns and 12% have triplets. Approximately 140 fawns are born for every 100 does in the population.

Birth weight for female fawns averages 5 ½ pounds; males average 7 ½ pounds. The fawn can walk shortly after birth, but stays close to its mother for several days. A fawn's coat is similar to an adult's, but has several hundred white spots along the back. This dappling provides camouflage in the shadows and thickets beneath trees. The spots gradually disappear when the deer is three to four months old.

At 2 – 3 weeks of age, fawns begin eating vegetation in addition to nursing. They are weaned at about four months, but can survive without milk at three months or less. About 30% of fawns do not survive until fall.

Antlers

Only bucks have antlers. Rack development is controlled by the male sex hormone but also depends on nutrition and sunlight levels. Antler growth begins in late winter/early spring as tiny fuzz-covered buds, which actually push out the old antlers, just as adult teeth push out baby teeth in humans. Very fine-haired skin, called velvet, protects the antler as it grows. Early autumn sunsets cause testosterone to rise in the buck’s body and signals velvet deterioration. As the luxuriant skin dies, it dries and itches, causing bucks to scratch by running their antlers along any available surface. By the time breeding season arrives, antlers are smooth and ready for battles with other males for breeding rights.

Antlers are solid and bony, except for the caribou, and form only on males.
Other ruminants have hollow permanent horns.
Antler growth requires large quantities of calcium.
When growth is complete, circulation to the antlers is cut off.
Antlers are used to slash territorial markings on trees or bushes, make threatening displays, and to combat other males.
Males sometimes lock antlers and die of exhaustion or starvation.
Antlers in a given species may vary in size, depending on the quality and quantity of food; in overpopulated areas, deer usually have small antlers.
Yearling bucks may have one to six points on each side of their antler but generally average a total of six points on both sides.
Large typical bucks can have seven or more points on each side; the number of points is not an indication of age, but rather of the animal’s physical condition.
Antlers are generally shed in January and February.

Importance of Deer

In addition to sport and meat (venison), deer contributions to society include:

Musk from the musk deer is used in medicine and perfume.
Deerskin is used for shoes, boots, and gloves.
Deer antlers are made into buttons and knife handles.
In various parts of the world, reindeer are used for food, clothing, and transport.
Hunters bolster the economy by spending millions annually on deer hunting permits and paraphernalia.

On the negative side, deer:

Cause many car accidents.
Significantly damage growing and stored agricultural crops.
Damage homes and yards in suburban neighborhoods.

References

The University of Michigan Museum of Zoology Animal Diversity Web
Nebraska Parks Commission