Deer (plural and singular) are the members of the Cervidae family of the order Artiodactyla, or even-toed hoofed mammals, with two large and two small hooves on each foot.
A characteristic of deer is that almost all species have antlers, a biological structure that is unique to deer. Other ruminants have horns. Antlers consist of bony outgrowths from the head with no covering of keratin as is found in true horns.
Deer generally have lithe, compact bodies and long, powerful legs suited for rugged woodland terrain.
Deer range from very large to very small.
The moose or elk is the largest species in the deer family. It can grow up to 2 meters (6.5 feet) from hoof to shoulder and weigh around 820 kilograms (1,800 pounds).
The Southern pudu is smallest species in the deer family. It weighs only around 9 kilograms (20 pounds) and gets to be only around 36 centimeters (14 inches) tall when fully grown.
The lifespan of deer is from 10 to 25 years depending on the species; though many die long before then due to predators or environmental dangers such as collisions with cars.
Biologically speaking, deer are crepuscular; feeding mainly from before dawn until several hours after, and again from late afternoon until dusk.
Deer have their eyes on the sides of their head, giving them a 310 degree view. This wide view does make it hard for deer to focus on a single point. Deer have a good night vision, which is useful in the early morning and near dusk.
Deer have a great sense of hearing. They have a lot of muscles attached to their ears which allow them to turn their ears in any direction, without moving their heads. They can hear higher frequencies of sound than humans.
Also they have an excellent sense of smell, which allows them to detect predators from a long distance away. Deer lick their nose to keep it moist, which helps odor particles stick to it, improving their sense of smell.
Deer are social animals and travel in groups called herds. The herd is often led by a dominant male, though with some species the herds are segregated by sex. Sometimes the females will have their own herd and the males will have a separate herd. In other cases, a female herd is watched over by a herd of males. Some reindeer (also known as the caribou) herds can have as many as 100,000 members.
Although most deer live in herds, some species, such as South American marsh deer, are solitary.
Deer use three main types of communication: vocal, chemical, and visual.
Deer produce scents with glands located on their head, legs and hooves. These scents provide information to other deer about their gender, social status, physical condition and whether an area is safe.
In temperate-zone deer, antlers begin growing in the spring as skin-covered projections from the pedicels. The dermal covering, or “velvet,” is rich in blood vessels and nerves. When antlers reach full size, the velvet dies and is rubbed off as the animal thrashes its antlers against vegetation. Antlers are used during male-male competition for mates during breeding season, and are shed soon afterwards.
Although most deer are polygynous, some species are monogamous (e.g., European Roe deer). The breeding season of most deer is short. In some species, males establish territories, which encompass those of one or more females. In some deer, females may form small groups known as harems, which are guarded and maintained by males, and in other species males simply travel between herds looking for females.
Deer carry their young for a gestation period of 180 to 240 days.
Deer usually only have one or two young at a time (triplets, while not unknown, are uncommon) and these young are called fawns. Some of the large deer babies are also called calves.
The fawn is able to stand in 10 minutes and can walk in 7 hours!
Deer range in color from dark to very light brown; however, young are commonly born with spots, that helps camouflage them from potential predators.
Fawns are protected by a lack of scent. Enemies cannot smell them. The mother keeps them hidden in bushes and checks up on them about 6 times a day to feed them. Young deer stay with their mothers for 1-2 years.
The IUCN’s Red List of Threatened Species includes the Calamian deer, Bawean deer, hog deer, Persian Fallow deer and the Chinanteco deer. The Père David’s deer is extinct in the wild and now can only be found in captive populations.
Only one species, the reindeer has been domesticated.
The only female deer with antlers are reindeer.
Chinese water deer are the only deer species not to have antlers. Instead, it has very long canine teeth that it uses to attract mates.
Moose have the largest antlers.
Deer antlers are the fastest growing tissue on Earth!
The Irish Elk (Megaloceros giganteus or Megaceros) is a huge extinct deer and the largest known species of deer to have ever lived. It died out about 11,000 years ago. It is famous for its formidable size (about 2.1 meters (7 feet) at the shoulders), and in particular for having the largest antlers of any known deer (a maximum of 3.65 meters (12 feet) from tip to tip)
Deer appear in art from Palaeolithic cave paintings onwards, and they have played a role in mythology, religion, and literature throughout history, as well as in heraldry.