|Barbary Sheep, Ammotragus lervia|
A goat-antelope, or caprid, is any of the species of mostly medium-sized bovids that make up the subfamily Caprinae (as treated here), part of the Bovidae family of ruminants. The domestic sheep and domestic goat are both part of the goat-antelope group by its widest definition, but some taxonomists[who?] prefer to use the term only for members of the Caprinae that are not members of the tribe Caprini (caprines). The 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.
Although most goat-antelopes are gregarious and have fairly stocky builds, they diverge in many other ways – the muskox (Ovibos moschatus) is adapted to the extreme cold of the tundra; the Rocky Mountain goat (Oreamnos americanus) of North America is specialised for very rugged terrain; the urial (Ovis orientalis) occupies a largely infertile area from Kashmir to Iran, including much desert country. The European mouflon (Ovis musimon) is thought to be the ancestor of the modern domestic sheep (Ovis aries).
Many species became 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 1 m (3 ft) long for a full-grown grey goral (Nemorhaedus goral), to almost 2.5 m (8 ft 2 in) long for a musk ox, and from under 30 kg (66 lb) to more than 350 kg (770 lb). Musk oxen in captivity have reached over 650 kg (1,430 lb).
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, tassellated ears, long manes, and dagger-shaped horns. The grazers (sometimes collectively known as tsoan caprids, from the Semitic tso'wn meaning "to migrate") 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.
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 (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 flocking for defence against predators, and goats adapting to very steep terrain where predators are at a disadvantage.
- Subfamily Caprinae
- Tribe Ovibovini
- Tribe Caprini
- Genus Ammotragus
- Barbary sheep, Ammotragus lervia
- Genus Arabitragus
- Arabian tahr, Arabitragus jayakari
- Genus Capra
- Genus Hemitragus
- Himalayan tahr, Hemitragus jemlahicus
- Genus Ovis
- Genus Nilgiritragus
- Nilgiri tahr, Nilgiritragus hylocrius
- Genus Pseudois
- Genus Ammotragus
- Tribe Naemorhedini
- Genus Capricornis
- Genus Nemorhaedus
- Genus Oreamnos
- Mountain goat, Oreamnos americanus
- Genus Rupicapra
||This article includes a list of references, but its sources remain unclear because it has insufficient inline citations. (July 2012)|