 = Oribi = 
 
 Oribi ( pronounced / <unk> / ) ( <unk> ourebi ) is a small antelope found in eastern , southern and western Africa . The sole member of its genus , the oribi was first described by the German zoologist <unk> August Wilhelm von Zimmermann in 1782 . Eight subspecies are identified . The oribi reaches nearly 50 – 67 centimetres ( 20 – 26 in ) at the shoulder and weighs 12 – 22 kilograms ( 26 – 49 lb ) . This antelope features a slightly raised back , and long neck and limbs . The glossy , yellowish to rufous brown coat contrasts with the white chin , throat , underparts and rump . Only males possess horns ; the thin , straight horns , 8 – 18 centimetres ( 3 @.@ 1 – 7 @.@ 1 in ) 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 , 25 – 100 hectares ( 62 – 247 acres ) large . The oribi is primarily a <unk> , and prefers fresh grasses and <unk> 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 – <unk> , polygyny and <unk> . Gestation lasts for six to seven months , following which a single calf is born ; births peak from November to December in southern Africa . <unk> takes place at four to five months . 
 The oribi occurs in a variety of habitats – from <unk> , floodplains and tropical grasslands with 10 – 100 centimetres ( 3 @.@ 9 – 39 @.@ 4 in ) tall grasses to <unk> grasslands at low altitudes , up to 2 @,@ 000 metres ( 6 @,@ 600 ft ) above the sea level . This antelope is highly sporadic in distribution , ranging from Senegal in the west to Ethiopia and Eritrea in the east and southward to Angola and the Eastern Cape ( South Africa ) . The oribi has been classified as Least Concern by the IUCN ; numbers have declined due to agricultural expansion and competition from livestock . 
 
 = = Taxonomy = = 
 
 The scientific name of the oribi is <unk> ourebi . The sole member of its genus , the oribi is placed under the family <unk> . The species was first described by the German zoologist <unk> August Wilhelm von Zimmermann in 1782 . The oribi was formerly included in the tribe <unk> , that comprised a variety of other dwarf antelopes , including <unk> ( <unk> ) , <unk> ( <unk> <unk> ) , <unk> , <unk> ( <unk> ) and <unk> . In 1963 , German <unk> Theodor <unk> separated the oribi and <unk> into a new tribe , <unk> ; later on , zoologist Jonathan <unk> assigned the oribi to <unk> , a tribe of its own . The common name " oribi " ( pronounced / <unk> / ) comes from the <unk> name for the animal , <unk> . 
 In a revision of the phylogeny of the tribe <unk> on the basis of nuclear and mitochondrial data in 2013 , Eva <unk> <unk> ( of the University of Cambridge ) and colleagues showed that the oribi is the sister taxon to all other <unk> . The cladogram below is based on the 2013 study . 
 The following eight subspecies are identified : 
 Of these , <unk> Colin Groves and Peter <unk> identify O. o. hastata , O. o. <unk> , O. o. ourebi and O. o. <unk> as independent species in their 2011 publication <unk> Taxonomy . 
 
 = = Description = = 
 
 The oribi is a small , slender antelope ; it reaches nearly 50 – 67 centimetres ( 20 – 26 in ) at the shoulder and weighs 12 – 22 kilograms ( 26 – 49 lb ) . The head @-@ and @-@ body length is typically between 92 and 110 centimetres ( 36 and 43 in ) . <unk> dimorphic , 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 rufous brown coat contrasts with the white chin , throat , underparts and rump . The bushy tail , brown to black on the outside , has white <unk> ( 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 <unk> . 
 Only males possess horns ; the thin , straight horns , 8 – 18 centimetres ( 3 @.@ 1 – 7 @.@ 1 in ) long , are smooth at the tips and ringed at the base . The maximum horn length , 19 @.@ 1 centimetres ( 7 @.@ 5 in ) , was recorded in 1998 from Malawi . The oribi has at least six different , well @-@ developed scent glands ( such as the prominent <unk> glands near the eyes ) . The body has several modifications , such as the large <unk> below the eyes , to accommodate such a large number of glands . Females have four <unk> . 
 
 = = Ecology and behaviour = = 
 
 The oribi is diurnal ( active mainly during the day ) , though some activity may also be observed at night . The animal rests in cover during rain events . Unlike all other small antelopes , oribi can exhibit three types of mating systems , depending on the habitat – <unk> , polygyny and <unk> ; 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 territory , 25 – 100 hectares ( 62 – 247 acres ) 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 vegetation and soil in their territories by <unk> <unk> <unk> and <unk> ; the intensity of marking increases with the number of male neighbours . <unk> 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 <unk> . 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 <unk> such as <unk> . 
 
 = = = Diet = = = 
 
 Primarily a <unk> , the oribi prefers fresh grasses and <unk> occasionally . Grasses can constitute up to 90 % of the diet ; preferred varieties include <unk> , <unk> , <unk> , <unk> , <unk> and <unk> species . Mineral <unk> are also visited regularly . Oribi have been observed feeding on flowers and Boletus mushrooms . Groups of oribi <unk> 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 <unk> ( which lasts for four to six days ) , it seeks the company of males . During courtship , the male will pursue the female , test her urine to check if she is in <unk> and <unk> her rump and flanks . Gestation 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 <unk> it for nearly half an hour . Males may guard their offspring from predators and keep away other males . <unk> 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 <unk> , floodplains and tropical grasslands with 10 – 100 centimetres ( 3 @.@ 9 – 39 @.@ 4 in ) tall grasses to <unk> grasslands at low altitudes , up to 2 @,@ 000 metres ( 6 @,@ 600 ft ) 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 110 centimetres ( 43 in ) of annual rainfall and open floodplains . The oribi 's range overlaps with those of larger <unk> such as the African buffalo , <unk> , <unk> , Thomson 's <unk> and <unk> . These separate species often occur in close proximity to each other , increasing predator <unk> . 
 This antelope is highly sporadic in distribution ; it occurs mainly in eastern , southern and western Africa , ranging from Nigeria and Senegal in the west to Ethiopia and Eritrea in the east and southward to Angola and the Eastern Cape ( South Africa ) . It is feared to be extinct in <unk> . 
 
 = = <unk> and conservation = = 
 
 The oribi has been classified as Least Concern by the IUCN . The total population ( as of 2008 ) is estimated at 750 @,@ 000 . However , the subspecies O. o. <unk> 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 <unk> National Park ( <unk> d <unk> ) 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 : <unk> <unk> National Park in Nigeria , the <unk> and W National Parks ( <unk> ) ; <unk> Hunting Zone ( Chad ) ; <unk> , <unk> <unk> and <unk> National Parks ( Cameroon ) ; <unk> @-@ <unk> St. <unk> National Park ( Central African Republic ) ; <unk> , <unk> and <unk> National Parks ( Congo @-@ <unk> ) ; <unk> National Park ( Ethiopia ) ; <unk> Mara Game Reserve and <unk> National Park ( Kenya ) ; Golden Gate Highlands National Park ( South Africa ) ; <unk> National Park ( Tanzania ) ; <unk> Valley , Lake <unk> and Murchison Falls National Parks ( Uganda ) ; <unk> and <unk> Plain National Parks and <unk> Swamp ( Zambia ) . 
 
 