The East African oryx (''Oryx beisa''), also known as the beisa is a species of

antelope The term antelope is used to refer to many species of even-toed ruminant that are indigenous to various regions in Africa and Eurasia. Antelope comprise a wastebasket taxon defined as any of numerous Old World grazing and browsing hoofed mamm ...

from

East Africa East Africa, Eastern Africa, or East of Africa, is the eastern subregion of the African continent. In the United Nations Statistics Division scheme of geographic regions, 10-11-(16*) territories make up Eastern Africa: Due to the historica ...

. It has two

subspecies In biological classification, subspecies is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics ( morphology), but that can successfully interbreed. Not all specie ...

: the

common beisa oryx The common beisa oryx (''Oryx beisa beisa''), also known as the beisa oryx, is the nominate subspecies of the East African oryx native to the Horn of Africa and Kenya. It is closely related to the fringe-eared oryx. There are four species of o ...

(''Oryx beisa beisa'') found in

steppe In physical geography, a steppe () is an ecoregion characterized by grassland plains without trees apart from those near rivers and lakes. Steppe biomes may include: * the montane grasslands and shrublands biome * the temperate gras ...

and semidesert throughout the

Horn of Africa The Horn of Africa (HoA), also known as the Somali Peninsula, is a large peninsula and geopolitical region in East Africa.Robert Stock, ''Africa South of the Sahara, Second Edition: A Geographical Interpretation'', (The Guilford Press; 2004 ...

and north of the Tana River, and the

fringe-eared oryx The fringe-eared oryx (''Oryx callotis'' or ''Oryx beisa callotis''), is a large species or subspecies of oryx antelope native to east Africa. It was originally described as a distinct species by Oldfield Thomas in 1892, but was subsequently re ...

(''Oryx beisa callotis'') south of the Tana River in southern

Kenya ) , national_anthem = " Ee Mungu Nguvu Yetu"() , image_map = , map_caption = , image_map2 = , capital = Nairobi , coordinates = , largest_city = Nairobi , ...

and parts of

Tanzania Tanzania (; ), officially the United Republic of Tanzania ( sw, Jamhuri ya Muungano wa Tanzania), is a country in East Africa within the African Great Lakes region. It borders Uganda to the north; Kenya to the northeast; Comoro Islands ...

. In the past, some

taxonomists In biology, taxonomy () is the scientific study of naming, defining ( circumscribing) and classifying groups of biological organisms based on shared characteristics. Organisms are grouped into taxa (singular: taxon) and these groups are given ...

considered it a subspecies of the

gemsbok The gemsbok or South African oryx (''Oryx gazella'') is a large antelope in the genus ''Oryx''. It is native to the extremely dry, arid regions of Southern Africa; notably, the Kalahari Desert. Some authorities formerly classified the East Afr ...

(''Oryx gazella''), but they are genetically distinct; the diploid chromosome count is 56 for the beisa and 58 for the gemsbok. The species is listed as Endangered by the IUCN.

Description

The East African oryx stands just over a metre at the shoulder and

weigh In science and engineering, the weight of an object is the force acting on the object due to gravity. Some standard textbooks define weight as a vector quantity, the gravitational force acting on the object. Others define weight as a scalar quan ...

s around . It has a grey coat with a white underside, separated from the grey by a stripe of black, with black stripes where the head attaches to the neck, along the nose, and from the eye to the mouth and on the forehead. The mane is small and chestnut-coloured; the ringed horns are thin and straight. They are found on both sexes and typically measure . Comparably, the gemsbok has an entirely black tail, a black patch at the base of the tail, and more black on the legs (including a patch on the hindlegs) and lower flanks. The smaller

Arabian oryx The Arabian oryx (''Oryx leucoryx'') or white oryx is a medium-sized antelope with a distinct shoulder bump, long, straight horns, and a tufted tail. It is a bovid, and the smallest member of the genus ''Oryx'', native to desert and steppe areas o ...

is overall whiter with largely dark legs.

Behaviour

East African oryx live in semidesert and steppes, where they eat

grass Poaceae () or Gramineae () is a large and nearly ubiquitous family of monocotyledonous flowering plants commonly known as grasses. It includes the cereal grasses, bamboos and the grasses of natural grassland and species cultivated in lawns a ...

es,

leaves A leaf ( : leaves) is any of the principal appendages of a vascular plant stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, st ...

fruit In botany, a fruit is the seed-bearing structure in flowering plants that is formed from the ovary after flowering. Fruits are the means by which flowering plants (also known as angiosperms) disseminate their seeds. Edible fruits in partic ...

and buds. They are able to store water by raising their body temperatures (so as to avoid

perspiration Perspiration, also known as sweating, is the production of fluids secreted by the sweat glands in the skin of mammals. Two types of sweat glands can be found in humans: eccrine glands and apocrine glands. The eccrine sweat glands are distr ...

). They gather in herds of five to 40 animals, often with females moving at the front and a large male guarding from the rear. Some older males are solitary. Radio tracking studies show the solitary males are often accompanied for brief periods by breeding-condition females, so it is probable they are executing a strategy to maximise their chances of reproduction.

Gallery

File:Beisa, Tsawo-Wes, Tanzanië.jpg, Fringe-eared oryx (''O. b. callotis'') File:Flickr - Rainbirder - Beisa Oryx (Oryx beisa).jpg, Common beisa oryx (''O. b. beisa'') File:The book of antelopes (1894) Oryx beisa.png, Illustration File:Přímorožec beisa zoo praha 1.jpg, In captivity

References

{{Taxonbar, from=Q792143

East African oryx The East African oryx (''Oryx beisa''), also known as the beisa is a species of antelope from East Africa. It has two subspecies: the common beisa oryx (''Oryx beisa beisa'') found in steppe and semidesert throughout the Horn of Africa and nort ...

Mammals of Ethiopia Mammals of Djibouti Mammals of South Sudan Mammals of Tanzania Mammals of Kenya Mammals of Somalia Fauna of East Africa