The Kalahari Desert is a large semi-arid sandy savanna in Southern Africa extending for 900,000 square kilometres, covering much of Botswana, and parts of Namibia and South Africa.
It is not to be confused with the Angolan, Namibian, and South African Namib coastal desert, whose name is of Khoekhoegowab origin and means "vast place".
Due to its low aridity, the Kalahari supports a variety of flora. The native flora includes acacia trees and many other herbs and grasses. The kiwano fruit, also known as the horned melon, melano, African horned cucumber, jelly melon, or hedged gourd, is endemic to a region in the Kalahari Desert (specific region unknown).
Even where the Kalahari "desert" is dry enough to qualify as a desert in the sense of having low precipitation, it is not strictly speaking a desert because it has too dense a ground cover. The main region that lacks ground cover is in the southwest Kalahari (southeast of Namibia, northwest of South Africa and southwest of Botswana) in the south of the Kgalagadi Transfrontier Park. For instance in the ZF Mgcawu District Municipality of South Africa, total vegetation cover may be as low as 30.72% on non-protected (from cattle grazing) farmlands south of Twee Rivieren Rest Camp and 37.74% in the protected (from cattle grazing) South African side of the Kgalagadi Transfrontier Park: these southernmost Kalahari xeric savanna areas are truly semi-deserts. However, in all the remaining Kalahari, except on salt pans during the dry season, the vegetation cover can be clearly denser, up to almost 100% in some limited areas.
In an area of about 600,000 km2 in the south and west of the Kalahari, the vegetation is mainly xeric savanna. This area is the ecoregion identified by World Wide Fund for Nature as Kalahari xeric savanna AT1309. Typical savanna grasses include Schmidtia, Stipagrostis, Aristida, and Eragrostis; these are interspersed with trees such as camelthorn (Acacia erioloba), grey camelthorn (Acacia haematoxylon), shepherd's tree (Boscia albitrunca), blackthorn (Acacia mellifera), and silver cluster-leaf (Terminalia sericea).
In certain areas where the climate is drier, it becomes a true semi-desert with ground not entirely covered by vegetation: "open" as opposed to "closed" vegetation. Examples include the north of the ZF Mgcawu District Municipality, itself in the north of South Africa, and the Keetmanshoop Rural in the southeast of Namibia. In the north and east, there are dry forests covering an area of over 300,000 km2 in which Rhodesian teak and several species of acacia are prominent. These regions are termed Kalahari Acacia-Baikiaea woodlands AT0709.
Outside the Kalahari "desert", but in the Kalahari basin, a halophytic vegetation to the north is adapted to pans, lakes that are completely dry during the dry season, and maybe for years during droughts, such as in Etosha (Etosha Pan halophytics AT0902) and Makgadikgadi (Zambezian halophytics AT0908).
A totally different vegetation is adapted to the perennial fresh water of the Okavango Delta, an ecoregion termed Zambezian flooded grasslands AT0907.
The Kalahari is home to many migratory birds and animals. Previously havens for wild animals from elephants to giraffes, and for predators such as lions and cheetahs, the riverbeds are now mostly grazing spots, though leopards and cheetahs can still be found. The area is now heavily grazed and cattle fences restrict the movement of wildlife. Among deserts of the Southern Hemisphere, the Kalahari most closely resembles some Australian deserts in its latitude and its mode of formation.
Although there are few endemic species, a wide variety of species are found in the region, including large predators such as the lion (Panthera leo), cheetah (Acinonyx jubatus), leopard (Panthera pardus), spotted hyena (Crocuta crocuta), brown hyena (Parahyaena brunnea), and African wild dog (Lycaon pictus pictus). Birds of prey include the secretary bird (Sagittarius serpentarius), martial eagle (Polemaetus bellicosus) and other eagles, the giant eagle owl (Bubo lacteus) and other owls, falcons, goshawks, kestrels, and kites. Other animals include wildebeest, springbok and other antelopes, porcupines (Hystrix africaeaustralis) and ostriches (Struthio camelus).
Some of the areas within the Kalahari are seasonal wetlands, such as the Makgadikgadi Pans of Botswana. This area, for example, supports numerous halophilic species, and in the rainy season, tens of thousands of flamingos visit these pans.
The biggest threat to wildlife are the fences erected to manage herds of grazing cattle, a practice which also removes the plant cover of the savanna itself. Cattle ranchers will also poison or hunt down predators from the rangeland, particularly targeting jackals and wild dogs.