A goat antelope is any of the species of mostly medium-sized herbivores that make up the subfamily Caprinae or the single species in subfamily Panthalopinae. The domestic sheep and domestic goat are both part of the goat antelope group, and the group itself is part of the family Bovidae, which in other branches contains the antelopes and domestic cattle.
Although most goat antelopes are gregarious and have a fairly stocky build, they diverge in many other ways. The musk ox became adapted to the extreme cold of the tundra; the Mountain goat of North America specialised in very rugged terrain; the Urial, occupied a largely infertile area from Kashmir to Iran, including much desert country. The Mouflon is the ancestor of modern domestic sheep.
Many of the ice age species are now extinct, 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 a metre for a full-grown Goral to almost 2.5 metres for a Musk Ox, and from under 30 kg to more than 350 kg. Musk Oxen in captivity have reached over 650 kg.
In lifestyle, the 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, tasselated ears, a long mane, 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. There is no sharp dividing line between the groups, just a continuum between the serows at one end of the spectrum and sheep, true goats, and Musk Oxen at the other.
The ancestors of the modern sheep and goats (both rather vague and ill-defined terms) are thought to have moved into mountainous regions: sheep becoming specialised occupants of the foothills and nearby plains, and relying on flight and clumping for defence against predators; goats adapting to very steep terrain where predators are at a disadvantage.