The oribi (; Ourebia ourebi ) is a small antelope 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. 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). It possesses 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. 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, polygyny and polygynandry. Gestation 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 savannahs, floodplains and tropical grasslands with 10–100 centimetres (3.9–39.4 in) tall grasses to montane 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.
Oribis are small delicate antelopes found in Africa. They have 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 is brown to black on the outside with white insides. Only males have horns that are thin, straight and smooth at the tips and ringed at the base.
Oribis are found 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). These antelopes live in savannahs, floodplains, tropical grasslands, and montane grasslands. Recently burnt areas also often attract groups of oribi.
Oribis are active mainly during the day, but sometimes may also be active at night. They are social and live in small groups that consist of up to four members. However, during the rainy season, when grasses are abundant, oribis can associate in bigger groups. Males are territorial and defend their group's territory from intruders. They mark vegetation and soil in their territories by preorbital gland secretions and excrement. Oribis have a very interesting behavior called the "dung ceremony", in which all animals form temporary dung middens. They do this in order to maintain social bonds within the group. When threatened, oribis prefer to hide in bushes or grasses and stay still with their ears down. If they are spotted, they will sprint through the open plain. After 200 m they may look back to see if they are still pursued, and will run again in a zig-zag motion in order to lose a predator. When alarmed oribis may make vertical leaps with straight legs; this behavior is called "stotting". When sensing danger these antelopes produce alarm whistles. These whistles are usually made by adults, and males appear to whistle more.
Oribis are herbivorous animals and prefer to graze on fresh grasses. They also regularly visit mineral licks and feed on herbs, leaves, flowers, and mushrooms.
Oribis have a polyandrous (a female has multiple mates), polygynous (a male has multiple mates) and polygynandrous (promiscuous) (both males and females have multiple mates) mating systems. Oribis are seasonal breeders and the time of mating varies with location. The peak usually occurs in the rainy season, from August to September. Females give birth to a single calf after the gestation period that lasts 6-7 months. In southern Africa births peak from November to December. The newborn is kept in hidden place during the first month after birth. The mother visits her calf regularly to suckle it for nearly half an hour. Males may guard their offspring from predators and keep away other males. Weaning usually takes place at 4 to 5 months. Females become reproductively mature when they are ten months old and males are ready to start breeding at fourteen months of age.
Main threats to oribis are poaching, agricultural expansion and competition from livestock.
According to the IUCN Red List, the total population size of oribis is around 750,000 individuals. Currently, this species is classified as Least Concern (LC) on the IUCN Red List but its numbers today are decreasing.
