The large and beautiful Gemsbok (also known as the Southern Oryx) is synonymous with South Africa’s arid Karoo and Kalahari regions. They occur under the harshest imaginable conditions in the Namib desert, but also in a wide range of more hospitable environments, such as open thornveld, mopane shrub and open grasslands, and are often encountered on rocky hillsides in these areas. Gemsbok are mixed feeders, consuming mostly short grass, leaves and shoots, roots and tubers, fruits and seedpods, showing specific preferences in each season. They are entirely independent of drinking water, but will drink up to 9 liters a day when it is available.
Gemsbok bulls can weigh up to 240kg and stand up to 1.3m high at the shoulder. Cows are slightly smaller in build, but usually have longer (and thinner) horns. For such large animals they are superbly adapted to a life in harsh, arid environments, being able to concentrate their urine and reabsorbing the maximum possible moisture from their dung. Gemsbok can even allow their body temperature to rise from a normal 36°C to 45°C before having to sweat and pant to cool down!
Gemsbok occur in herds consisting of cows, calves and non-breeding bulls that move over the territories of several dominant territorial breeding males. The mixed herds are normally quite small, numbering between 5 and 40 animals, but can at times form temporary aggregations of up to 300 strong in response to favourable localised conditions. Breeding herds can cover enormous home ranges, especially during times of drought. They are normally active in the early morning and late afternoon, and often throughout the night, resting up during the heat of the day in any available shade.
Gemsbok are brave and aggressive, and thus very dangerous, especially when wounded or cornered or when protecting their calves. Single calves are born away from the herd at the end of the dry season, and remain hidden for the first few weeks after birth. Mothers return to the calves twice daily for nursing until she introduces the calf to the herd at between 3 and 6 weeks of age. Adult Gemsbok are only attacked by lions and spotted hyenas, who are often killed in the process, but unattended calves are easy prey for most of Africa’s predators. Gemsbok have a natural life expectancy of up to 20 years.
Gemsbok occur in South Africa, Zimbabwe, Botswana and Namibia, with the IUCN estimating a total population of between 326,000 and 373,000 and recognising no major threats to their continued survival. South Africa’s biggest single population of Gemsbok occur in the Kgalagadi Transfrontier Park, but they can also be seen at Karoo, Mapungubwe, Marakele, Mokala and Mountain Zebra National Parks, several other game and nature reserves, and on many private farms, where they are a popular game ranching species. The Beisa Oryx (Oryx beisa) from East Africa is now considered a seperate species.