
Terminology
The word "deer" was originally quite broad in meaning, but became more specific over time. In Middle English der (O.E. dēor) meant a wild animal of any kind (as opposed to cattle, which then meant any domestic livestock).This general sense gave way to the modern sense by the end of the Middle English period, around 1500. Cognates of English "deer" in several other languages

For most deer the male is called a buck and the female is a doe, but terminology varies according to the size of the species. For many medium-sized deer the male is a stag and the female a hind, while for many larger deer the same words are used as for cattle: bull and cow. Terms for young deer vary similarly, with that of most being called a fawn and that of the larger species calf; young of the smallest kinds may be a kid. A group of deer of any kind is a herd. Usage of all these terms may also vary according to dialect. The adjective of relation pertaining to deer is cervine; like the family name "Cervidae" this is from Latin cervus, "deer".
The word hart is an old alternative word for "stag" (from Old English heorot, "deer" – compare with modern Dutch hert, also "deer"). It is not now widely used, but Shakespeare makes several references (for example in Twelfth Night), punning on the sound-alike "hart" and "heart". "The White Hart" and "The Red Hart" remain common English pub names, and the county Hertfordshire is thought to be named after a place where deer forded a watercourse. Whinfell Forest once contained a landmark tree called Harthorn.
Habitat
Deer are widely distributed, and hunted, with indigenous representatives in all continents except Antarctica and Australia, though Africa has only one native species, the Red Deer, confined to the Atlas Mountains in the northwest of the continent.

Small species of brocket deer and pudús of Central and South America, and muntjacs of Asia generally occupy dense forests and are less often seen in open spaces, with the possible exception of the Indian Muntjac. There are also several species of deer that are highly specialized, and live almost exclusively in mountains, grasslands, swamps, and "wet" savannas, or riparian corridors surrounded by deserts. Some deer have a circumpolar distribution in both North America and Eurasia. Examples include the caribou that live in Arctic tundra and taiga (boreal forests) and moose that inhabit taiga and adjacent areas. Huemul Deer (taruca and Chilean Huemul) of South America's Andes fill an ecological niche of the ibex or Wild Goat, with the fawns behaving more like goat kids.
The highest concentration of large deer species in temperate North America lies in the Canadian Rocky Mountain and Columbia Mountain Regions between Alberta and British Columbia where all five North American deer species (White-tailed deer, Mule deer, Caribou, Elk, and Moose) can be found. This region has several clusters of national parks including Mount Revelstoke National Park, Glacier National Park (Canada), Yoho National Park, and Kootenay National Park on the British Columbia side, and Banff National Park, Jasper National Park, and Glacier National Park (U.S.) on the Alberta and Montana sides. Mountain slope habitats vary from moist coniferous/mixed forested habitats to dry subalpine/pine forests with alpine meadows higher up. The

The Eurasian Continent (including the Indian Subcontinent) boasts the most species of deer in the world, with most species being found in Asia. Europe, in comparison, has lower diversity in plant and animal species. However, many national parks and protected reserves in Europe do have populations of Red Deer, Roe Deer, and Fallow Deer. These species have long been associated with the continent of Europe, but also inhabit Asia Minor, the Caucasus Mountains, and Northwestern Iran. "European" Fallow Deer historically lived over much of Europe during the Ice Ages, but afterwards became restricted primarily to the Anatolian Peninsula, in present-

The highest concentration of large deer species in temperate Asia occurs in the mixed deciduous forests, mountain coniferous forests, and taiga bordering North Korea, Manchuria (Northeastern China), and the Ussuri Region (Russia). These are among some of the richest deciduous and coniferous forests in the world where one can find Siberian Roe Deer, Sika Deer, Elk, and Moose. Asian Caribou occupy the northern fringes of this region along the Sino-Russian border.
Deer such as the Sika Deer, Thorold's deer, Central Asian Red Deer, and Elk have historically been farmed for their antlers by Han Chinese, Turkic peoples, Tungusic peoples, Mongolians, and Koreans. Like the Sami people of Finland and Scandinavia, the Tungusic peoples, Mongolians, and Turkic peoples of Southern Siberia, Northern Mongolia, and the Ussuri Region have also taken to raising semi-domesticated herds of Asian Caribou.

The Chao Praya River Valley of Thailand was once primarily tropical seasonal moist deciduous forest and wet savanna that hosted populations of Hog Deer, the now-extinct Schomburgk's Deer, the Eld's Deer, Indian Sambar, and Indian Muntjac. Both the Hog Deer and Eld's Deer are rare, whereas Indian Sambar and Indian Muntjac thrive in protected national parks such as Khao Yai.
Many of these South Asian and Southeast Asian deer species also share their habitat with various herbivores such as Asian Elephants, various Asian rhinoceros species, various antelope species (such as nilgai, Four-horned Antelope, blackbuck, and Indian gazelle in India), and wild oxen (such as Wild Asian Water Buffalo, gaur, banteng, and kouprey). How different herbivores

Australia has six introduced species of deer that have established sustainable wild populations from acclimatisation society releases in the 19th Century. These are Fallow Deer, Red Deer, Sambar Deer, Hog Deer, Rusa deer, and Chital. Red Deer introduced into New Zealand in 1851 from English and Scottish stock were domesticated in deer farms by the late 1960s and are common farm animals there now. Seven other species of deer were introduced into New Zealand but none are as widespread as Red Deer.
Biology
Extant deer range in size from the 10 kg (22 lb) Northern Pudu to the 450 kg (990 lb) Moose. They generally have lithe, compact bodies and long, powerful legs suited for rugged woodland terrain. Deer are also excellent jumpers and swimmers. Deer are ruminants, or cud-chewers, and have a four-chambered stomach. The teeth of deer are adapted to feeding on vegetation, and like other ruminants, they lack upper incisors, instead having a tough pad at the front of their upper jaw. The Chinese water deer, Tufted deer and muntjac have enlarged upper canine teeth forming sharp tusks, while other species often lack upper canines altogether. The cheek

Nearly all deer have a facial gland in front of each eye. The gland contains a strongly scented pheromone, used to mark its home range. Bucks of a wide range of species open these glands wide when angry or excited. All deer have a liver without a gallbladder. Deer also have a Tapetum lucidum which gives them sufficiently good night vision.
A doe generally has one or two fawns at a time (triplets, while not unknown, are uncommon). The gestation period is anywhere up to ten months for the European Roe Deer. Most fawns are born with their fur covered with white spots, though in many species they lose their spots once they get older. In the first twenty minutes of a fawn's life, the fawn begins to take its first steps. Its mother licks it clean until it is almost free of scent, so predators will not find it. Its mother leaves often, and the fawn does not like to be left behind. Sometimes its mother must gently push it down with her foot.The fawn stays hidden in the grass for one week until it is strong enough to walk with its mother. The fawn and its mother stay together for about one year. A
Fawn
Deer are selective feeders. They are usually browsers, and primarily feed on leaves. They have small, unspecialized stomachs by ruminant standards, and high nutrition requirements. Rather than attempt to digest vast quantities of low-grade, fibrous food as, for example, sheep and cattle do, deer select easily digestible shoots, young leaves, fresh grasses, soft twigs, fruit, fungi, and lichens.a