Oribi

Ourebia ourebi

General Description

Scientific Name: Oreotragus oreotragus

Subspecies: 11 Subspecies

O. o. dorcas
O. o. gallarum
O. o. haggardi
O. o. hastata
O. o. kenyae (extinct)
O. o. montana
O. o. ourebi
O. o. quadriscopa
O. o. rutila
Status: Least Concern (Decreasing)

Population Estimate: 750,000 minimum

Population in Assessed Areas: Unassessed

Diet: Herbivore - Primary Grazer

Male Size: 11-17 Kgs

Female Size: 8-20 Kgs

Trophy Size: 32.02 cm minimum

Generation Length: 3.9 years

Reproductive Season: October - December

Time of Activity: Diurnal

Description: Oribi are small, sexually dimorphic antelopes, with Females being slightly larger than males (except in the case of O. o. ourebi, whose females are smaller), though similar in length. On average, oribi reach about 50-67cm tall at the shoulder and weigh mostly between 12-22kg.

Only rams have horns, which are thin, straight, and long; ringed at the base and smooth at the tip. Oribi have horns of about 8-18cm, the longest recorded length being 19.1cm. Females have four teats.

Colour and appearance vary slightly by location and subspecies, but a general description is applicable: oribi are small and slender, with long limbs and necks. They have a short, glossy coat whose colour ranges from a yellowish tan to rufous brown, with white fur for the chin, throat, rump and underparts. The short black tail also generally has a white underside, while the black ears often have white insides. The facial markings often include white fur above the eyes and a black glandular spot below each ear. Oribi have six different scent glands whose locations are preorbital, inguinal, inter-digitally, and on the shin. Oribi are often mistaken for the Steenbok, but oribi have longer necks, smaller hooves, and a black tail compared to the Steenbok’s red tail.

Ecology: Oribi depend on tall grasses of up to 100cm for both food and refuge, so they inhabit high-rainfall areas. They are not reliant on water sources as hydration is mostly acquired through their diet. Oribi prefer floodplains, open plains, grasslands (including montane grasslands), and marginally inhabit light bushland. Preferred varieties of grass include Andropogon, Eulalia, Hyparrhenia, Loudetia, Pennisetum, and Themeda.

Oribi live in habitats up to 2,000 metres above sea level and are often attracted to recently burnt areas. Habitats are chosen depending on the availability of cover from predators. Population density is usually 2-10 individuals per square kilometer as oribi live in territorial pairs and groups. Higher densities are recorded in tropical grasslands with >110 centimeters of annual rainfall. Oribi often occur in close proximity to larger grazers like the Cape Buffalo, Elephants and large antelopes.

Behavior: Oribi are diurnal but occasionally active at night. Uniquely, oribi exhibit three mating systems, depending on their habitat and population sex ratio – polyandry (multi-male), polygyny (multi-female) and polygynandry (multi-male and multi-female). Polygyny is preferred in high predator-risk areas for forming protective groups.

Males defend their territory, which is usually 25–100 hectares in size. Female members may also show territorial aggression. Males mark their territories with preorbital gland secretions and excrement in the vegetation and soil. Their thoroughness varies depending on the number of male neighbours, and dominant males have greater access to. An important social behaviour of oribi is the formation of dung middens to mark territory. Upon sensing danger, oribi let out three alarm whistles. This is more common in adults, and males whistle more.

Predation: the most significant predators of the Oribi are Leopards, Caracals, and jackals, but other species like cheetahs, hyenas, lions, aneagles and even pythons will opportunistically predate on these animals, where their habitat overlaps.

Reproduction: Both males and females sexually mature at 10-14 months. Mating time varies geographically, as oribi breed seasonally and usually peak in the rainy season. Female oestrus lasts 4-6 days. In courtship, the male pursues the female, testing her urine to see if she is in oestrus and lick her rump and flanks. Gestation lasts 6-7 months and a single calf is born. Births usually peak in November and December. The newborn is concealed for around a month, during which the mother pays regular visits to suckle the calf, weaning after 4-5 months. Males guard their offspring from predators and other males. The oribi lives for 8-12 years in the wild.

Conservation Analysis

Current & Historic range: The distribution of the Oribi is highly sporadic in distribution; inhabiting mainly eastern, southern and western Africa, from Nigeria and Senegal to Ethiopia and Eritrea, as well as Angola and the Eastern Cape. Oribi are thought to be extinct in Burundi. Many of it's populations are separated by large areas of unsuitable habitat, indicating that sometime in the past when the climate was different, it may have has a larger range that even in historic times.

The species occurs across a large portion of it's historic range, especially in remote areas with high elevation, where poaching and livestock occur less frequently. In some areas, it has been extirpated, due to excessive hunting (mainly by the bushmeat trade) but also due to land use changes, from wilderness to agricultural lands. Not only does this damage their habitat, but it also increases the population of people in the area, and hence increasing human hunting pressure.

Current & Historic Populations:. the historic population number of the Oribi is largely unknown, though it is likely to be significantly larger than current populations. Large areas of their range has seen a change in land use over the past 100+ years, switching from a grazing ecosystem controlled by wild grazers, to pastoral land used to graze livestock and house people. Current Population estimates conducted in 1999 place the species at over 750,000 individuals across their entire range, but whether that number is still accurate today is unknown. It's decreasing trend outside of protected areas does threaten these populations, and will likely result in some populations going extinct in the next 50 years if left alone.

Map of Oribi Distribution

Threats to Species Survival: Oribi are under relatively little threat, because their populations prove somewhat resistant to hunting. Nevertheless, the main threats to oribi are poaching, agricultural expansion, and competition with livestock. The most affected subspecies is O. o. haggardi – as of 2008, their population was at ~10,000 and decreasing.

Recommended Conservation Actions:

Greatly increased regulation in the Bush Meat industry, including a ban on the sale of blue duiker meat in many parts of their range. This should be done whilst allowing for local subsistence harvests, and regulated tourism hunting.
Promote the application of incentives for landowners to preserve this species on their property.
Increase surveying capabilities of most of it's populations, especially outside of protected areas, where much about the status of this species is unknown.

Economic & Cultural Analysis

Ecotourism Value: Low

Hunting Value: Moderate

Meat Value: Moderate to High

Average Trophy Value: $1,300 USD

Meat Yield per Animal: 6-10 kg

Economic Value/Impacts: Oribi can have significant economic value in many areas, both for their meat value, and for their trophy value. They are a valuable bushmeat animal, as well as a very valuable trophy, especially compared to their relative size. Many properties preserve Oribi for this specific reason, especially where raising livestock is not profitable or within larger protected areas.

Their value to ecotourism areas is significantly less, as their small size and reclusive nature means they often aren't noticed, and if they are, they're often overshadowed by more charismatic megafauna.

Cultural Value: Oribi have likely been hunted by humans and our ancestors for millions of years, and because of their abundance in some areas of their range, they can be a staple food source for hunter-gatherer communities. Hunting small antelopes like Oribi with the aid of dogs is still common till this day, as it increases the success of the hunt.

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