Oribi  (Ourebia ourebi)

Oribi sitting in grass

Facts

Kingdom Animalia
Phylum Chordata
Class Mammalia
Order Artiodactyla
Family Bovidae
Genus Ourebia (1)
Size Head-body length: 92 – 140 cm (2)
Shoulder height: 50 – 70 cm (2)
Weight 14 – 21 kg (2)

Status

The oribi is classified as Lower Risk / Conservation Dependent (LR/cd) on the IUCN Red List 2007 (1). Two subspecies are recognised: Haggard's oribi (Ourebia ourebi haggardi) is classified as Vulnerable (VU) and the Kenya oribi (Ourebia ourebi kenyae) is classified as Extinct (EX) (1).

Description

The smallest true grazer amongst the antelope (3), the oribi is a medium-sized ungulate with slender legs, a long neck, and small pointed horns. The silky coat of the oribi is yellow to reddish-brown on the back but is white on the belly. Each knee has a long tuft of hair, and the tail is short and black with a white underside. The eyes have a white line of fur above them, often used to help distinguish them from other ungulate species. Beneath the ears are dark, hairless patches, and on the sides of the face are vertical creases that house the preorbital glands. These glands produce an odorous secretion that is used to mark the oribi's territory (2) (4).

Range

The oribi occurs in the savannah grasslands of Africa south of the Sahara. Haggard's oribi is found in Kenya and Somalia, and the Kenya oribi was found only in Kenya (2).

UNEP World Conservation Monitoring CentreView a distribution map for this species at UNEP World Conservation Monitoring Centre.

Habitat

Inhabits open grasslands, preferring habitats with short grasses on which to graze, interspersed with tall grasses for hiding in (2) (4).

Biology

Oribi are commonly found in pairs or in groups of as many as seven (2). Such groups usually have a single adult male (2), and up to three adult females (3). These groups are territorial (2), and will mark the boundaries of their territory with urine, faeces and secretions from the preorbital glands on their faces (2). Active during the day, oribi graze on fresh grass during the wet season, and browse on shrubs when drought occurs. To supplement their diet, oribi visits mineral licks every few days (4).

Although oribi may give birth throughout the year, birthing is said to be most common in the rainy months (4), when there is plentiful food and cover (2). After a gestation period of 200 to 210 days, a single young is born (2). Male oribi become sexually mature by 14 months, while females can conceive at the age of just 10 months (4).

If threatened by a predator, the oribi will remain hiding in tall grass until the predator is within a few metres. It will then leap through the grass and bound along, flashing the conspicuous white underside of its tail which serves as a warning to other oribi (2). Oribi will also produce a shrill whistle when alarmed and are seen to jump vertically up with all four legs straight and the back arched when they are under threat, known as stotting (4).

Threats

The oribi is intensively hunted for food and its habitat is threatened by the development of human settlements (1) (2), resulting in numbers and distribution of this small antelope being greatly reduced (2).

Conservation

The oribi is found in several protected areas throughout its range, including Comoé National Park in Cote d'Ivoire and Serengeti National Park, Tanzania (5), and is the subject of a WWF Species Project (6). This project aims to track captive-bred oribi after their release into appropriate habitat to research their home ranges and their habitat preferences. The long-term aim of the project is to establish viable wild populations from captive-bred stock (6).

Authentication

Authenticated (12/08/08) by Professor Robin Dunbar, Institute of Cognitive and Evolutionary Anthropology, University of Oxford.

Gestation: The state of being pregnant; the period from conception to birth.
Preorbital glands: An organ that produces a secretion, situated in front of the eye socket.
Subspecies: A population usually restricted to a geographical area that differs from other populations of the same species, but not to the extent of being classified as a separate species.
Territory: Area occupied and defended by an animal, a pair of animals or a colony.
Ungulate: A hoofed, grazing mammal.

References

  1. IUCN Red List (August, 2008)
    http://www.iucnredlist.org
  2. Nowak, R.M. (1999) Walker's Mammals of the World. Johns Hopkins University Press, Baltimore, Maryland.
  3. Dunbar, R. (2008) Pers. Comm.
  4. Estes, R. and Otte, D. (1991) The Behavior Guide to African Mammals. University of California Press, California.
  5. UNEP-WCMC World Database on Protected Areas (August, 2008)
    http://www.unep-wcmc.org/wdpa
  6. WWF (December, 2004)
    http://www.panda.org.za/species_projects.htm