The subfamily Caprinae is part of the ruminantfamilyBovidae, and consists of mostly medium-sized bovids. A member of this subfamily is called a caprine, or, more informally, a goat-antelope; however, this term "goat-antelope" does not mean that these animals are true antelopes: a true antelope is a bovid with a cervid-like or antilocaprid-like morphology. Within this subfamily Caprinae, a prominent tribe, Caprini, includes sheep and goats. Some earlier taxonomies considered Caprinae a separate family called Capridae, but now it is usually considered a subfamily within the family Bovidae, whence a caprine is a kind of bovid.
Characteristics
Although most goat-antelopes are gregarious and have fairly stocky builds, they diverge in many other ways - the muskox is adapted to the extreme cold of the tundra; the mountain goat of North America is specialised for very rugged terrain; the urial occupies a largely infertile area from Kashmir to Iran, including much desert country. The European mouflon is thought to be the ancestor of the modern domestic sheep. Many species have become extinct since the last ice age, probably largely because of human interaction. Of the survivors:
Five are classified as endangered,
Eight as vulnerable,
Seven as of concern and needing conservation measures, but at lower risk, and
Seven species are secure.
Members of the group vary considerably in size, from just over long for a full-grown grey goral, to almost long for a musk ox, and from under to more than. Musk oxen in captivity have reached over. The lifestyles of caprids fall into two broad classes: 'resource-defenders', which are territorial and defend a small, food-rich area against other members of the same species; and 'grazers', which gather together into herds and roam freely over a larger, usually relatively infertile area. The resource-defenders are the more primitive group: they tend to be smaller in size, dark in colour, males and females fairly alike, have long, tessellated ears, long manes, and dagger-shaped horns. The grazers evolved more recently. They tend to be larger, highly social, and rather than mark territory with scent glands, they have highly evolved dominance behaviours. No sharp line divides the groups, but a continuum varies from the serows at one end of the spectrum to sheep, true goats, and musk oxen at the other.
Evolution
The goat-antelope, or caprid, group is known from as early as the Miocene, when members of the group resembled the modern serow in their general body form. The group did not reach its greatest diversity until the recent ice ages, when many of its members became specialised for marginal, often extreme, environments: mountains, deserts, and the subarctic region. The ancestors of the modern sheep and goats are thought to have moved into mountainous regions - sheep becoming specialised occupants of the foothills and nearby plains, and relying on flight and flocking for defence against predators, and goats adapting to very steep terrain where predators are at a disadvantage.
