The Bovidae comprise the biological family of cloven-hoofed, ruminant mammals that includes cattle, bison, buffalo, antelopes, and goat-antelopes. A member of this family is called a bovid. With 143 extant species and 300 known extinct species, the family Bovidae consists of two major subfamilies and twelve major tribes. The family evolved 20 million years ago, in the early Miocene.
The bovids show great variation in size and pelage colouration. Excepting some domesticated forms, all male bovids have two or more horns, and in many species, females possess horns, too. The size and shape of the horns vary greatly, but the basic structure is always one or more pairs of simple bony protrusions without branches, often having a spiral, twisted or fluted form, each covered in a permanent sheath of keratin. Most bovids bear 30 to 32 teeth.
Most bovids are diurnal. Social activity and feeding usually peak during dawn and dusk. Bovids typically rest before dawn, during midday, and after dark. They have various methods of social organisation and social behaviour, which are classified into solitary and gregarious behaviour. Bovids use different forms of vocal, olfactory, and tangible communication. Most species alternately feed and ruminate throughout the day. While small bovids forage in dense and closed habitat, larger species feed on high-fiber vegetation in open grasslands. Most bovids are polygynous. Mature bovids mate at least once a year and smaller species may even mate twice. In some species, neonate bovids remain hidden for a week to two months, regularly nursed by their mothers; in other species, neonates are followers, accompanying their dams, rather than tending to remain hidden.
The greatest diversities of bovids occur in Africa. The maximum concentration of species is in the savannas of eastern Africa. Other bovid species also occur in Europe, Asia, and North America. Bovidae includes three of the five domesticated mammals whose use has spread outside their original ranges, namely cattle, sheep, and goats. Dairy products, such as milk, butter, and cheese, are manufactured largely from domestic cattle. Bovids are also raised for their leather, meat, and wool.
Most of the diverse bovid species occur in Africa. The maximum concentration is in the savannas of eastern Africa. Depending on their feeding habits, several species have radiated over large stretches of land, and hence several variations in dental and limb morphology are observed. Duikers inhabit the equatorial rainforests, sitatunga, and lechwe occur near swamps, eland inhabit grasslands, springbok and oryx occur in deserts, bongo and anoa live in dense forests, and mountain goats and takin live at high altitudes. A few bovid species also occur in Europe, Asia, and North America. Sheep and goats are found primarily in Eurasia, though the Barbary sheep and the ibex form part of the African fauna. The muskox is confined to the arctic tundra. Several bovid species have been domesticated by human beings. The domestication of goats and sheep began 10 thousand years ago, while cattle were domesticated about 7.5 thousand years ago.