The oribi (; ''Ourebia ourebi'') is a small

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 ...

found in eastern, southern and western Africa. The sole member of its genus, it was described by the German zoologist Eberhard August Wilhelm von Zimmermann in 1783. While this is the only member in the

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

''Ourebia'', eight

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 ...

are identified. The oribi reaches nearly at the shoulder and weighs . It possesses a slightly raised back, and long neck and limbs. The glossy, yellowish to

rufous Rufous () is a color that may be described as reddish-brown or brownish-red, as of rust or oxidised iron. The first recorded use of ''rufous'' as a color name in English was in 1782. However, the color is also recorded earlier in 1527 as a dia ...

brown coat contrasts with the white chin, throat, underparts and rump. Only males possess horns; the thin, straight horns, long, are smooth at the tips and ringed at the base. Typically diurnal, the oribi is active mainly during the day. Small herds of up to four members are common; males defend their group's

territory A territory is an area of land, sea, or space, particularly belonging or connected to a country, person, or animal. In international politics, a territory is usually either the total area from which a state may extract power resources or a ...

, large. It is primarily a grazer, and prefers fresh grasses but also browses occasionally. A seasonal breeder, the time when mating occurs varies geographically. Unlike all other small antelopes, oribi can exhibit three types of mating systems, depending on the habitat –

polyandry Polyandry (; ) is a form of polygamy in which a woman takes two or more husbands at the same time. Polyandry is contrasted with polygyny, involving one male and two or more females. If a marriage involves a plural number of "husbands and wives" ...

polygyny Polygyny (; from Neoclassical Greek πολυγυνία (); ) is the most common and accepted form of polygamy around the world, entailing the marriage of a man with several women. Incidence Polygyny is more widespread in Africa than in any ...

and

polygynandry Polygynandry is a mating system in which both males and females have multiple mating partners during a breeding season. In sexually reproducing diploid animals, different mating strategies are employed by males and females, because the cost of gam ...

Gestation Gestation is the period of development during the carrying of an embryo, and later fetus, inside viviparous animals (the embryo develops within the parent). It is typical for mammals, but also occurs for some non-mammals. Mammals during pr ...

lasts for six to seven months, following which a single calf is born; births peak from November to December in southern Africa. Weaning takes place at four to five months. The oribi occurs in a variety of habitats – from

savannah A savanna or savannah is a mixed woodland-grassland (i.e. grassy woodland) ecosystem characterised by the trees being sufficiently widely spaced so that the canopy does not close. The open canopy allows sufficient light to reach the ground to ...

s, floodplains and tropical grasslands with tall grasses to montane grasslands at low altitudes, up to above the sea level. This antelope is highly sporadic in distribution, ranging from

Senegal Senegal,; Wolof: ''Senegaal''; Pulaar: 𞤅𞤫𞤲𞤫𞤺𞤢𞥄𞤤𞤭 (Senegaali); Arabic: السنغال ''As-Sinighal'') officially the Republic of Senegal,; Wolof: ''Réewum Senegaal''; Pulaar : 𞤈𞤫𞤲𞤣𞤢𞥄𞤲𞤣𞤭 ...

in the west to

Ethiopia Ethiopia, , om, Itiyoophiyaa, so, Itoobiya, ti, ኢትዮጵያ, Ítiyop'iya, aa, Itiyoppiya officially the Federal Democratic Republic of Ethiopia, is a landlocked country in the Horn of Africa. It shares borders with Eritrea to the ...

and

Eritrea Eritrea ( ; ti, ኤርትራ, Ertra, ; ar, إرتريا, ʾIritriyā), officially the State of Eritrea, is a country in the Horn of Africa region of Eastern Africa, with its capital and largest city at Asmara. It is bordered by Ethiopi ...

in the east and southward to

Angola , national_anthem = "Angola Avante"() , image_map = , map_caption = , capital = Luanda , religion = , religion_year = 2020 , religion_ref = , coordinat ...

and the

Eastern Cape The Eastern Cape is one of the provinces of South Africa. Its capital is Bhisho, but its two largest cities are East London and Gqeberha. The second largest province in the country (at 168,966 km2) after Northern Cape, it was formed in ...

(

South Africa South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded to the south by of coastline that stretch along the South Atlantic and Indian Oceans; to the north by the neighbouring coun ...

). The oribi has been classified as

Least Concern A least-concern species is a species that has been categorized by the International Union for Conservation of Nature (IUCN) as evaluated as not being a focus of species conservation because the specific species is still plentiful in the wild. ...

by the

IUCN The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natu ...

; numbers have declined due to agricultural expansion and competition from livestock.

Taxonomy

The book of antelopes (1894) Ourebia nigricaudata

The

scientific name In taxonomy, binomial nomenclature ("two-term naming system"), also called nomenclature ("two-name naming system") or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, bo ...

of the oribi is ''Ourebia ourebi''. The sole member of its genus, the oribi is placed under the family

Bovidae The Bovidae comprise the biological family of cloven-hoofed, ruminant mammals that includes cattle, bison, buffalo, antelopes, and caprines. A member of this family is called a bovid. With 143 extant species and 300 known extinct species, t ...

. The species was first described by the German zoologist Eberhard August Wilhelm von Zimmermann in 1782. It was formerly included in the

tribe The term tribe is used in many different contexts to refer to a category of human social group. The predominant worldwide usage of the term in English is in the discipline of anthropology. This definition is contested, in part due to confl ...

Neotragini, that comprised a variety of other dwarf

s, including '' Dorcatragus'' (beira), '' Madoqua'' (dik dik), ''

Neotragus ''Neotragus'' is a genus of dwarf antelope, native to Africa. The genus includes only a single species without any dispute, namely '' Neotragus pygmaeus''. Neotragus pygmaeus is the smallest antelope in the world, they usually weigh around 5 to ...

'', '' Oreotragus'' (klipspringer) and '' Raphicerus''. In 1963, German mammalogist Theodor Haltenorth separated the oribi and ''Raphicerus'' into a new tribe, Raphicerini; later on, zoologist

Jonathan Kingdon Jonathan Kingdon (born 1935 in Tanzania) is a zoologist, science author, and artist; a research associate at the University of Oxford. He focuses on taxonomic illustration and evolution of the mammals of Africa. He is a contributor to The Oxford ...

assigned the oribi to Ourebini, a tribe of its own. The common name "oribi" comes from the

Afrikaans Afrikaans (, ) is a West Germanic language that evolved in the Dutch Cape Colony from the Dutch vernacular of Holland proper (i.e., the Hollandic dialect) used by Dutch, French, and German settlers and their enslaved people. Afrikaans gr ...

name for the animal, ''oorbietjie''. In a revision of the

phylogeny A phylogenetic tree (also phylogeny or evolutionary tree Felsenstein J. (2004). ''Inferring Phylogenies'' Sinauer Associates: Sunderland, MA.) is a branching diagram or a tree showing the evolutionary relationships among various biological s ...

of the

Antilopini Antilopini is a tribe of bovids often referred as true antelopes like gazelles. They live in and around the Sahara, Horn of Africa, throughout eastern and southern Africa, and Eurasia. Depending on species, the females have either very short and/ ...

on the basis of

nuclear Nuclear may refer to: Physics Relating to the nucleus of the atom: *Nuclear engineering *Nuclear physics *Nuclear power *Nuclear reactor *Nuclear weapon *Nuclear medicine *Radiation therapy *Nuclear warfare Mathematics *Nuclear space *Nuclear ...

and

mitochondria A mitochondrion (; ) is an organelle found in the cells of most Eukaryotes, such as animals, plants and fungi. Mitochondria have a double membrane structure and use aerobic respiration to generate adenosine triphosphate (ATP), which is used ...

l data in 2013, Eva Verena Bärmann (of the

University of Cambridge , mottoeng = Literal: From here, light and sacred draughts. Non literal: From this place, we gain enlightenment and precious knowledge. , established = , other_name = The Chancellor, Masters and Schola ...

) and colleagues showed that the oribi is the

sister taxon In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an evolutionary tree. Definition The expression is most easily illustrated by a cladogram: Taxon A and ...

to all other antilopines. The

cladogram A cladogram (from Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an evolutionary tree because it does not show how ancestors are related to ...

below is based on the 2013 study. The following eight

are identified: *''O. o. dorcas'' Schwarz, 1914 *''O. o. gallarum'' Blaine, 1913 *''O. o. haggardi'' (

Thomas Thomas may refer to: People * List of people with given name Thomas * Thomas (name) * Thomas (surname) * Saint Thomas (disambiguation) * Thomas Aquinas (1225–1274) Italian Dominican friar, philosopher, and Doctor of the Church * Thomas the A ...

, 1895) – Occurs in eastern Africa. Listed as Vulnerable by the

. *''O. o. hastata'' ( Peters, 1852) – Ranges from Kenya southward into Mozambique and eastward into Angola *

† A dagger, obelisk, or obelus is a typographical mark that usually indicates a footnote if an asterisk has already been used. The symbol is also used to indicate death (of people) or extinction (of species). It is one of the modern descendan ...

'' O. o. kenyae'' Meinhertzhagen, 1905 – Occurred on the lower slopes of

Mount Kenya Mount Kenya (Kikuyu language, Kikuyu: ''Kĩrĩnyaga'', Kamba language, Kamba, ''Ki Nyaa'') is the highest mountain in Kenya and the Highest mountain peaks of Africa, second-highest in Africa, after Mount Kilimanjaro, Kilimanjaro. The highest pea ...

. *''O. o. montana'' ( Cretzschmar, 1826) – Ranges from northern Nigeria eastward into Ethiopia and southward into Uganda. *''O. o. ourebi'' ( Zimmermann, 1783) – Its range lies south of

Zambezi River The Zambezi River (also spelled Zambeze and Zambesi) is the fourth-longest river in Africa, the longest east-flowing river in Africa and the largest flowing into the Indian Ocean from Africa. Its drainage basin covers , slightly less than hal ...

. *''O. o. quadriscopa'' ( C. H. Smith, 1827) – Occurs in western Africa *''O. o. rutila'' Blaine, 1922 Of these, zoologists

Colin Groves Colin Peter Groves (24 June 1942 – 30 November 2017) was a British-Australian biologist and anthropologist. Groves was Professor of Biological Anthropology at the Australian National University in Canberra, Australia. Education Born in Englan ...

and Peter Grubb identify ''O. o. hastata'', ''O. o. montana'', ''O. o. ourebi'' and ''O. o. quadriscopa'' as independent species in their 2011 publication ''Ungulate Taxonomy''.

Description

The oribi is a small, slender antelope; it reaches nearly at the shoulder and weighs . The head-and-body length is typically between .

Sexually dimorphic Sexual dimorphism is the condition where the sexes of the same animal and/or plant species exhibit different morphological characteristics, particularly characteristics not directly involved in reproduction. The condition occurs in most ani ...

, males are slightly smaller than females (except for ''O. o. ourebi'', in which females are smaller). This antelope features a slightly raised back, and long neck and limbs. The glossy, yellowish to

brown coat contrasts with the white chin, throat, underparts and rump. The bushy tail, brown to black on the outside, has white insides (except in ''O. o. hastata'', that has a completely black tail). The subspecies show some variation in colouration; ''O. o. ourebi'' is a rich rufous, while ''O. o. hastata'' is yellower. Only males possess horns; the thin, straight horns, long, are smooth at the tips and ringed at the base. The maximum horn length, , was recorded in 1998 from

Malawi Malawi (; or aláwi Tumbuka: ''Malaŵi''), officially the Republic of Malawi, is a landlocked country in Southeastern Africa that was formerly known as Nyasaland. It is bordered by Zambia to the west, Tanzania to the north and northe ...

. The oribi has at least six different, well-developed

scent gland Scent gland are exocrine glands found in most mammals. They produce semi-viscous secretions which contain pheromones and other semiochemical compounds. These odor-messengers indicate information such as status, territorial marking, mood, and s ...

s (such as the prominent

preorbital gland The preorbital gland is a paired exocrine gland found in many species of hoofed animals, which is homologous to the lacrimal gland found in humans. These glands are trenchlike slits of dark blue to black, nearly bare skin extending from the me ...

s near the eyes). The body has several modifications, such as the large fossae below the eyes, to accommodate such a large number of glands. Females have four teats.

Ecology and behaviour

Sudan Oribis (Ourebia montana) (18231586045)

The oribi is diurnal (active mainly during the day), though some activity may also be observed at night. It rests in cover during rain events. Unlike all other small antelopes, oribi can exhibit three types of mating systems, depending on the habitat –

and

; polygyny tends to prevail as the female-to-male ratio increases. A study suggested that polygyny is preferred in areas of high predator risk, as it leads to formation of groups as an anti-predator measure. Small herds of up to four members are also common. Males defend their group's

, large; female members may also show some aggression and drive away intruders. A study showed that the number of females that visit the male's territory depends on the appearance (particularly the symmetry) of the male's horns. Males

mark Mark may refer to: Currency * Bosnia and Herzegovina convertible mark, the currency of Bosnia and Herzegovina * East German mark, the currency of the German Democratic Republic * Estonian mark, the currency of Estonia between 1918 and 1927 * Finn ...

vegetation and soil in their territories by preorbital gland secretions and excrement; the intensity of marking increases with the number of male neighbours. Dominant males tend to have greater access to females in and around the territory than other males. An important feature of the social behaviour of oribi is the "dung ceremony", in which all animals form temporary dung middens. Oribi at least three months old have been observed giving out one to three alarm whistles on sensing danger. These whistles are more common in adults than in juveniles, and males appear to whistle more. Common predators include

carnivora Carnivora is a Clade, monophyletic order of Placentalia, placental mammals consisting of the most recent common ancestor of all felidae, cat-like and canidae, dog-like animals, and all descendants of that ancestor. Members of this group are f ...

ns such as

jackal Jackals are medium-sized canids native to Africa and Eurasia. While the word "jackal" has historically been used for many canines of the subtribe canina, in modern use it most commonly refers to three species: the closely related black-backed ...

Diet

Primarily a grazer, the oribi prefers fresh grasses and browses occasionally. Grasses can constitute up to 90% of the diet; preferred varieties include ''

Andropogon ''Andropogon'' (common names: beard grass, bluestem grass, broomsedge) is a widespread genus of plants in the grass family, native to much of Asia, Africa, and the Americas, as well as southern Europe and various oceanic islands. Over 100 specie ...

'', '' Eulalia'', ''

Hyparrhenia ''Hyparrhenia'' is a genus of grasses. Many species are known commonly as thatching grass. They are mostly native to tropical Africa; some can be found in warmer areas in temperate Eurasia, Australia, and Latin America. These are annual and per ...

'', ''

Loudetia ''Loudetia'' is a genus of African, Arabian, and South American plants in the grass family.Pennisetum ''Pennisetum'' is a widespread genus of plants in the grass family, native to tropical and warm temperate regions of the world. They are known commonly as fountaingrasses (fountain grasses).Themeda'' species.

Mineral lick A mineral lick (also known as a salt lick) is a place where animals can go to lick essential mineral nutrients from a deposit of salts and other minerals. Mineral licks can be naturally occurring or artificial (such as blocks of salt that fa ...

s are also visited regularly. Oribi have been observed feeding on flowers and ''

Boletus ''Boletus'' is a genus of mushroom-producing fungi, comprising over 100 species. The genus ''Boletus'' was originally broadly defined and described by Carl Linnaeus in 1753, essentially containing all fungi with hymenial pores instead of ...

'' mushrooms. Groups of oribi congregate in the rainy season, when grasses are abundant.

Reproduction

Both sexes become sexually mature at 10 to 14 months. A seasonal breeder, the time when mating occurs varies geographically. Mating may peak in the rainy season (August to September). When a female enters

oestrus The estrous cycle (, originally ) is the set of recurring physiological changes that are induced by reproductive hormones in most mammalian therian females. Estrous cycles start after sexual maturity in females and are interrupted by anestrou ...

(which lasts for four to six days), she seeks the company of males. During courtship, the male will pursue the female, test her urine to check if she is in oestrus and lick her rump and flanks.

lasts for six to seven months, following which a single calf is born; births peak from November to December in southern Africa. The newborn is kept in concealment for nearly a month; the mother pays regular visits to her calf to suckle it for nearly half an hour. Males may guard their offspring from predators and keep away other males. Weaning takes place at four to five months. The oribi lives for 8 to 12 years in the wild, and for 12 to 14 years in captivity.

Distribution and habitat

The oribi occurs in a variety of habitats – from

s, floodplains and tropical grasslands with tall grasses to montane grasslands at low altitudes, up to above the sea level. Recently burnt areas often attract groups of oribi. The choice of habitat depends on the availability of cover needed to escape the eyes of predators. Population densities typically vary between 2 and 10 individuals per km²; however, densities as high as 45 individuals per km² have been recorded in tropical grasslands that receive over of annual rainfall and open floodplains. The oribi's range overlaps with those of larger grazers such as the African buffalo,

hippopotamus The hippopotamus ( ; : hippopotamuses or hippopotami; ''Hippopotamus amphibius''), also called the hippo, common hippopotamus, or river hippopotamus, is a large semiaquatic mammal native to sub-Saharan Africa. It is one of only two exta ...

hartebeest The hartebeest (; ''Alcelaphus buselaphus''), also known as kongoni or kaama, is an African antelope. It is the only member of the genus ''Alcelaphus''. Eight subspecies have been described, including two sometimes considered to be independ ...

, Thomson's gazelle and

topi ''Damaliscus lunatus jimela'' is a subspecies of topi, and is usually just called a topi. It is a highly social and fast type of antelope found in the savannas, semi-deserts, and floodplains of sub-Saharan Africa. Names The word ''tope'' or ''t ...

. These separate species often occur in close proximity to each other, increasing predator vigilance. This antelope is highly sporadic in distribution; it occurs mainly in eastern, southern and western Africa, ranging from

Nigeria Nigeria ( ), , ig, Naìjíríyà, yo, Nàìjíríà, pcm, Naijá , ff, Naajeeriya, kcg, Naijeriya officially the Federal Republic of Nigeria, is a country in West Africa. It is situated between the Sahel to the north and the Gulf o ...

and

in the west to

and

in the east and southward to

Angola , national_anthem = "Angola Avante"() , image_map = , map_caption = , capital = Luanda , religion = , religion_year = 2020 , religion_ref = , coordinat ...

and the

(

). It is feared to be extinct in

Burundi Burundi (, ), officially the Republic of Burundi ( rn, Repuburika y’Uburundi ; Swahili: ''Jamuhuri ya Burundi''; French: ''République du Burundi'' ), is a landlocked country in the Great Rift Valley at the junction between the African Gr ...

Threats and conservation

The oribi has been classified as

by the IUCN. The total population (as of 2008) is estimated at 750,000. However, the subspecies ''O. o. haggardi'' is listed as Vulnerable because, as of 2008, the total population is estimated at less than 10,000 mature individuals, and is feared to be declining. Hunting is a relatively minor threat, since the oribi shows some tolerance to hunting. Nevertheless, the steep fall of 92% in oribi populations in

Comoé National Park The Comoé National Park is a Biosphere Reserve and UNESCO World Heritage Site in the Zanzan and Savanes Districts of north-eastern Ivory Coast. It is the largest protected area in West Africa, with an area of 11,500 km2, and ranges from the ...

(

Côte d'Ivoire Ivory Coast, also known as Côte d'Ivoire, officially the Republic of Côte d'Ivoire, is a country on the southern coast of West Africa. Its capital is Yamoussoukro, in the centre of the country, while its largest city and economic centre ...

) has been attributed to poaching. Numbers have also declined due to agricultural expansion and competition from livestock. The oribi occurs in a number of protected areas throughout its range, such as: Gashaka Gumti National Park in

, the Pendjari and W National Parks (

Benin Benin ( , ; french: Bénin , ff, Benen), officially the Republic of Benin (french: République du Bénin), and formerly Dahomey, is a country in West Africa. It is bordered by Togo to the west, Nigeria to the east, Burkina Faso to the nort ...

); Aouk Hunting Zone (

Chad Chad (; ar, تشاد , ; french: Tchad, ), officially the Republic of Chad, '; ) is a landlocked country at the crossroads of North and Central Africa. It is bordered by Libya to the north, Sudan to the east, the Central African Republic ...

); Benoue, Bouba Njida and Faro National Parks (

Cameroon Cameroon (; french: Cameroun, ff, Kamerun), officially the Republic of Cameroon (french: République du Cameroun, links=no), is a country in west-central Africa. It is bordered by Nigeria to the west and north; Chad to the northeast; the ...

); Manovo-Gounda St. Floris National Park (

Central African Republic The Central African Republic (CAR; ; , RCA; , or , ) is a landlocked country in Central Africa. It is bordered by Chad to the north, Sudan to the northeast, South Sudan to the southeast, the DR Congo to the south, the Republic of th ...

); Garamba, Upemba and Kundelungu National Parks (

Congo-Kinshasa The Democratic Republic of the Congo (french: République démocratique du Congo (RDC), colloquially "La RDC" ), informally Congo-Kinshasa, DR Congo, the DRC, the DROC, or the Congo, and formerly and also colloquially Zaire, is a country in ...

); Omo National Park (

); Masai Mara Game Reserve and Ruma National Park (

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

); Golden Gate Highlands National Park (

);

Serengeti National Park The Serengeti National Park is a large national park in northern Tanzania that stretches over . It is located entirely in eastern Mara Region and north east portion of Simiyu Region and contains over of virgin savanna. The park was established ...

(

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 ...

); Kidepo Valley, Lake Mburo and

Murchison Falls Murchison Falls, also known as Kabalega Falls, is a waterfall at the apex of Lake Albert on the Victoria Nile in Uganda. At the top of Murchison Falls, the Nile forces its way through a gap in the rocks, only wide, and tumbles , before flowi ...

National Parks (

Uganda }), is a landlocked country in East Africa. The country is bordered to the east by Kenya, to the north by South Sudan, to the west by the Democratic Republic of the Congo, to the south-west by Rwanda, and to the south by Tanzania. The ...

);

Kafue Kafue is a town in the Lusaka Province of Zambia and it lies on the north bank of the Kafue River, after which it is named. It is the southern gateway to the central Zambian plateau on which Lusaka and the mining towns of Kabwe and the Copperb ...

and Liuwa Plain National Parks and Bangweulu Swamp (

Zambia Zambia (), officially the Republic of Zambia, is a landlocked country at the crossroads of Central, Southern and East Africa, although it is typically referred to as being in Southern Africa at its most central point. Its neighbours are t ...

References

External links

* * {{Taxonbar, from=Q275615 Dwarf antelopes Mammals of Sub-Saharan Africa Mammals described in 1783 Taxa named by Eberhard August Wilhelm von Zimmermann