Oryx - Desert Cavalry
Few of Africa's antelope can match the Oryx for its striking appearance and almost noble presence. Known in South Africa as the "Gemsbok", this handsome horse-like antelope is adapted for arid conditions, ranging across the Karoo and Kalahari, and deep into the Namib Desert. Seen from a distance, a herd on the move resemble a party of cavalry headed for battle.
Oryx are powerfully built, with long, arrow-straight horns. In common with their relatives - the Roan and Sable - both sexes have horns of almost equal length, though those of the males are thicker. With its bold black and white facial marking, offset by a greyish-ochre coat, the Oryx appears to have been put together by a group of graphic designers, such is the artistic symmetry of its coat. The average weight is around 250kg, the average shoulder height 120cm, and the average horn length 95cm. Apart from being visually striking, the Oryx is fascinating from both a morphological and behavioural perspective.
Coping with the heat
Oryx can survive without drinking water, as they are able to extract sufficient moisture from their diet and have various morphological adaptations (they will, however, drink readily if water is available). In order to survive temperatures of up to 45 degrees, the Oryx allows its own body temperature to rise accordingly to prevent the loss of water through sweating. The antelope's hot blood is passed through a network of carotid veins along its nasal passage, before entering the brain. This system is akin to a car radiator, as the blood is cooled by air flowing in and out of its nose as it pants. In addition to this adaptation, the Oryx also has highly efficient kidneys which eliminate waste products with a minimal loss of moisture by concentrating the urine. To offload the "stored heat" in their bodies, Oryx often move to the highest points in their range - for example a sand dune - where they stand side-on to maximise on the cooling effect of even a slight breeze.
Gregarious females, solitary males
Oryx are gregarious and typically form herds of up to 30 individuals. Larger herds may be associated with nomadic movements. Herds comprise adult females and their young, and sub-adult or subordinate males. Dominant males occupy territories through which the females pass and provide mating opportunities. Rivalry between neighbouring males, or new challengers, leads to extremely intense fights, which may result in snapped horns, serious injuries or even death. In battle, the males look for all the world like jousting knights of old. The territory size of males depends upon the terrain and availability of grass fodder, but ranges between eight and 30km². A single calf is born at any time of year, after a gestation period of 264 days. For the first few weeks of its life, the calf remains hidden, to be joined by its mother after dark.
Oryx feed primarily on grass, but will browse on certain shrubs and regularly eat succulent wild cucumbers and underground tubers, as well as Acacia seed pods. Oryx often kick and dig into the ground to expose and eat minerals, and also lick the salty crust of evaporated saline water.
Beware the Hyena
Spotted Hyena are the principle enemies of Oryx, with calves being particularly vulnerable. Hyenas use their great stamina to run down Oryx to a point of complete exhaustion, hunting by day or night. Once too tired to run, the Oryx will usually back itself into a thorny bush, from where it uses its rapier horns in defence. Lion and less often leopard may also prey upon Oryx from time to time.
Where to see Oryx at &Beyond destinations
Oryx are resident in the vicinity of Sossusvlei Mountain Lodge, and sightings of territorial males and female herds are frequent. To see these magnificent antelope against the backdrop of gigantic, naked sand dunes is an unforgettable sight. Mobile safaris in Namibia will encounter large numbers of Oryx at Etosha and in Damaraland, while Nxai Pan is a reliable locality for close encounters in Botswana. In the Eastern Cape, small numbers have been reintroduced to the Kwandwe Private Game Reserve.
Posted: Mammals by CC Africa, Date: 21 November 2006