Gemsbok  (Oryx gazella)

The most distinctive features of this heavily built antelope are its long, rapier-shaped horns and striking black and white facial markings (2). The beautiful horns of the gemsbok are sought after as charms in many cultures and were even sold as unicorn horns in medieval England (3). The body is fawn-grey with a black stripe along the side separating the upperparts from the white underparts (2). There are five subspecies of Oryx gazella including the gemsbok (Oryx gazella gazella), the beisa oryx (O.g. beisa) and the fringe-eared oryx (O.g. callotis) (4). The gemsbok has a broader black side stripe than the beisa and fringe-eared oryx, and also has more extensive black on its upper legs (2). The fringe-eared oryx can be distinguished from the beisa oryx by the long tufts of hair growing from the tips of the ears, from which it gets its name (2). All subspecies have long, horse-like tails, and whilst both sexes possess the impressive horns, those of the male are shorter and more robust than the female's. Gemsbok calves lack any black body markings (2).

O.g. gazella has an extensive distribution in south-west Africa, O.g. beisa has a widespread but fragmented distribution in the Horn of Africa, whilst O.g. callotis has the most limited distribution, in eastern Kenya and north-east Tanzania (2) (4).

Gemsboks generally occur in semi-arid to arid grasslands and bushlands, but also inhabit light woodland and, in the southern part of its range, sand dunes (2) (5).

The gemsbok is remarkably adapted to its arid environment; particularly noteworthy is its ability to survive without drinking water for most of the year (5). It conserves water within its body by lying in the shade during the hottest part of the day, and restricts activity to early mornings, late afternoons or the cool nights. The gemsbok does not waste precious moisture on panting or sweating, but instead allows its body temperature to rise by a few degrees above normal on hot days (5).

Gemsboks are gregarious animals, usually found in herds of up to 30 individuals (2), but occasionally herds of several hundred animals can be encountered as they move to fresh grazing grounds (2). Gemsbok feed primarily on grass but when this is not available they will browse on shrubs, trees and herbs (6). During periods of drought, they obtain moisture from roots and tubers which are dug up with their hooves (6).

From the age of five or six, male gemsboks establish territories. These territories are around 25 square kilometres and may be defended for up to three years (2). During this period, the male rounds up herds of females and young gemsbok into his territory to gain sole mating rights with receptive females (2). Single calves are born to females older than two years (5), after a pregnancy of around 264 days (6). The calf remains hidden during the day, but may venture out at night with the mother to a new site. At three to six weeks of age, the calf will join the herd (2). Gemsboks have a lifespan of around twenty years (6).

All subspecies of gemsbok have suffered population and range declines (2). The Beisa oryx and fringe-eared oryx have particularly declined in Somalia, Uganda and Sudan, but are still quite widespread in Ethiopia and pars of Kenya and Tanzania (6) (7). The habitat of the gemsbok continues to be encroached upon by humans and their livestock (1) (6). In addition, gemsboks face the threat of hunting (1), for their meat, hides and horns (3), which has the potential to greatly impact populations due to their slow reproductive rate (4).

The gemsbok occurs in many major national parks (6), where it receives protection from the threats of habitat loss and hunting. Therefore, whilst the gemsbok is not considered to yet be threatened with extinction, it is somewhat reliant on the continued enforcement of protected areas, and thus IUCN has classified it as Lower Risk / Conservation Dependent (1).

For further information on the gemsbok see:

• African Wildlife Foundation:
  www.awf.org/content/wildlife/detail/oryx

Authenticated (25/02/08) by Dr. David Mallon, Co-Chair, IUCN/SSC Antelope Specialist Group.