Botswana: Botswana Geography Profile

Its topography is punctuated only by the Tsodilo Hills in the extreme northwest.

Its major environmental issues include:

overgrazing;
desertification; and,
limited freshwater resources

Botswana is susceptible to eriodic droughts; seasonal August winds blow from the west, carrying sand and dust across the country, which can obscure visibility.

Botswana is noted for its expansive landscape of desert, semi-arid scrublands, salt pans, riverine delta and other generally level, low lying landscape.

To the southeast of the delta are the highly reflective Makgadigadi Pans. The Pans are large salt pans that are transformed into grasslands by the monsoon rains. Tthey are white and gray against the tan plateau and reddish hills.

In the southwestern corner of the country, the Kalahari Desert stretches for hundreds of miles.

Geography

Location: Southern Africa, north of South Africa

Geographic Coordinates: 22 00 S, 24 00 E

Area: 600,370 km2 (585,370 km2 land and 15,000 km2 water)

Arable land: 0.65%
Permanent crops: 0.01%
Other: 99.34% (2005)

Land Boundaries: 4013 kilometers (km). Border nations: Namibia 1360 km, South Africa 1840 km, Zimbabwe 813 km

Natural Hazards: periodic droughts; seasonal August winds blow from the west, carrying sand and dust across the country, which can obscure visibility

Terrain: Predominantly flat to gently rolling tableland; Kalahari Desert in the southwest. Its lowest topographic point is the junction of the Limpopo and Shashe Rivers (513 metres) and its highest point is Tsodilo Hills (1489 metres)

Climate: semiarid; warm winters and hot summers

Ecology and Biodiversity

A female Lechwe in the Okavango Delta, Botswana. Source: Wikimedia Commons

Botswana is a landlocked country of two million people in Southern Africa located instantly north of South Africa.

The people concentrated in eastern part of the country.

Formerly the British protectorate of Bechuanaland, Botswana adopted its present name upon independence in 1966.

Four decades of uninterrupted civilian leadership, low human people density, robust democracy, strong pride in environmental protection and significant capital investment have created one of the majority dynamic economies in Africa.

Mineral extraction, principally diamond mining, dominates economic activity, though tourism is a growing sector due to the country's conservation practices and extensive nature preserves.

Botswana has one of the world's highest known rates of HIV/AIDS infection, but as well one of Africa's most progressive and comprehensive programs for dealing with the disease.

Its topography is punctuated only by the Tsodilo Hills in the extreme northwest.

Its major environmental issues include:

overgrazing;
desertification; and,
limited freshwater resources

Botswana is susceptible to eriodic droughts; seasonal August winds blow from the west, carrying sand and dust across the country, which can obscure visibility.

Botswana is noted for its expansive landscape of desert, semi-arid scrublands, salt pans, riverine delta and other generally level, low lying landscape.

As seen in the image below, in the northwestern corner of the country, the Okavango River widens into a huge delta that feeds substantial marshland. The which stands out in dark green against a additional arid landscape.

To the southeast of the delta are the highly reflective Makgadigadi Pans. The Pans are large salt pans that are transformed into grasslands by the monsoon rains. Tthey are white and gray against the tan plateau and reddish hills.

In the southwestern corner of the country, the Kalahari Desert stretches for hundreds of miles.

Kalahari xeric savanna (Amber)

The Kalahari xeric savanna is an ecoregion in southern Africa characterized by a harsh climate, where temperatures may vary by 44°C from night to day, and rainfall is infrequent. Rain appears only during the summer on the reddish-brown Kalahari sands , pelting the savanna with violent, localized storms. Although this area is semi-arid, there is an impressive diversity of migratory birds and large mammals, both herbivorous and carnivorous; in fact, 550 different vertebrates have been observed in the Kalahari xeric savanna.

This ecoregion is classified within the Deserts and Xeric Shrublands biome. A considerable fraction (approximately 18 %) of the Kalahari xeric savanna is protected. Where lands are not protected, overgrazing has often severely degraded habitat. Fences are a significant problem because they obstruct the migratory patterns of ungulates, and as a result they pose significant threats to biodiversity in unprotected areas.

Location and general depiction

The Kalahari xeric savanna ecoregion stretches across northwestern South Africa, southern Botswana and southeastern Namibia. Most of this ecoregion lies on the level plains of the Kalahari Basin, interrupted by long, somewhat parallel sand dunes in the south. The Kalahari sands themselves extend from the northern Cape in South Africa to the Democratic Republic of Congo, and there is no consensus regarding their origin of formation. The sands of this ecoregion vary in depth, and are underlain chiefly by calcrete; in fact, this calcrete occurrence is responsible for a lot of of the aircraft landing strips in this remote region.

In places, native rock below the sands harbors substantial mineral wealth, in the form of diamonds, copper, and coal. The Kalahari sands are generally nutrient poor. A thin layer of iron oxide induces a reddish-brown colour, although water leaching in areas of higher rainfall or near pans commonly causes the colour to fade.

Climate

There has been a long term hydrological change in this region, which began with the diversion of a major river flow through the Botswanan portion of the region initiated by a geological rift zone anomaly hundreds of thousands of years ago. This flow alteration eliminated one of the major permanent lakes in all of Africa, and restored that depression with a seasonal wetland, the Makgadikgadi Pans. This change affected not only the water table, but as well the all of evaporation and total humidity and precipitation of the region.

Diurnal temperature fluctuations in the Kalahari are extreme. In the southern part of the ecoregion, temperatures on winter nights can plummet to 1°C, while soaring to 30°C during the afternoon. Similarly, a cold summer night may drop to 2°C, whereas the daytime temperature may exceed 46°C. Even the rain, at the same time as it falls, arrives most frequently in violent but brief thunderstorms. Rainfall is as well remarkably patchy, with great differences occurring between sites only a few kilometers distant. Average annual rainfall is highest in the northeast and lowest in the southwest, ranging between 150 and 500 millimeters. Inter-annual variability in rainfall increases from 25 % in the east to 40 % in the west. Latitude, high atmospheric pressure, and the barrier created by the Drakensberg Mountains between the Kalahari and the Indian Ocean are largely responsible for this climate. Topography and elevation are as well influential, and although the Kalahari xeric savanna occurs at elevations between 600 meters (m) and 1600 m, most of it lies above 1000 m.

Vegetation

In less arid areas, the vegetation is open savanna with grasses (Schmidtia spp., Stipagrostis spp., Aristida spp., and Eragrostis spp.) interrupted by trees such as Camelthorn (Acacia erioloba), Grey camelthorn (A. haematoxylon), Shepherd's tree (Boscia albitrunca), False umbrella-thorn (A. luederitzii), Blackthorn (A. mellifera), and Silver cluster-leaf (Terminalia sericea). Shrubs include Velvet raisin (Grewia flava), Ziziphus spp., Camphor bush (Tarchonanthus camphoratus), Rhigozum spp., Acacia hebeclada, and Lycium spp. In the additional arid sectors, large trees typically are found in ancient riverbeds, and the rolling red dunes are sparsely populated by smaller A. erioloba, A. haematoxylon, and B. albitrunca, inclunding broom scrub such as Crotalaria spartioides and Dune reed (Stipagrostis amabilis). Creeping Watermelon (Citrullus lanatus), Gemsbok cucumber (Acanthosicyos naudinianus), and Wild cucumber (Cucumis africanus) are vital sources of water and food for both humans and animals.

Plant species richness per unit area in the Kalahari xeric savanna is part the lowest of all the southern African ecoregions, and it is estimated that less than three % of the plants are endemic. Animal endemism is as well low; there are no strictly endemic birds and only three near-endemic birds; furthermore, there is only one near-endemic amphibian, one strictly endemic reptile (Typhlosaurus gariepensis) with nine near-endemic reptiles, and a single near-endemic small mammal, Brants's whistling rat (Parotomys brantsii).

Fauna

However, despite the low rates of endemism, the diversity of large mammals at all levels of the food chain is remarkable for such an oligotrophic and arid system. Some flora and fauna are almost synonymous with the region. These include the camelthorn tree, gemsbok (Oryx gazella), sociable weaver (Philetairus socius), and Kalahari lion (Panthera leo).

Mammals

Although not a separate species, the Kalahari lion exhibits behavioral adaptations to surviving in this harsh environment. It lives in small prides, has an expansive home range and hunts smaller prey than lions of additional mesic areas; however, large prey, particularly gemsbok, still represents the greatest biomass of food consumed. Its appearance is as well different, being taller at the shoulder, slighter in body mass, and with a lot of males exhibiting black manes. The Camelthorn is the sole common large tree in the region. It provides nesting and foraging sites, shade, food, and refuge for a gamut of plants and animals. The animals of the Kalahari xeric savanna evince a range of adaptations to the extremes of this arid ecoregion. Gemsbok are superbly physiologically adapted to the harsh climate and sparse forage.

Apart from the Kalahari lion, the ecoregion boasts an impressive array of other large predators, mainly in protected areas. These include the Cheetah (Acinonyx jubatus VU), Leopard (Panthera pardus), Spotted hyena (Crocuta crocuta LR) and Brown hyena (Hyaena brunnea LR), and Painted hunting dog (Lycaon pictus EN). The representation of smaller vertebrate predators is as well remarkable. Part the mammals are the Aardwolf (Proteles cristata), Caracal (Felis caracal), Black-backed jackal (Canis mesomelas), Honey badger (Mellivora capensis), African wildcat (Felis lybica), Black-footed cat (Felis nigripes), Striped polecat (Ictonyx striatus), Small-spotted genet (Genetta genetta), Bat-eared fox and Cape fox (Otocyon megalotis, Vulpes chama), inclunding Meerkat (Suricata suricatta) and three species of mongoose: Banded (Mungos mungo), Slender (Herpestes sanguinea), and Yellow (Cynictis penicillata).

Although the Cheetah is the swiftest land predator (capable of reaching speeds of 100 km per hour), its slight build and timid disposition make it subordinate to other carnivores, and it is often robbed of its prey. To avoid this, the cheetah usually hunts during the day, at the same time as most of its competitors are inactive. Its major prey are springbok (Antidorcas marsupialis LR), although at the same time as game is scarce, it will as well hunt young or weak Hartebeest (Alcelaphus buselaphus LR), Gemsbok, and Blue Wildebeest (Connochaetes taurinus LR), inclunding Duiker (Sylvicapra grimmia) and Springhare (Pedetes capensis), part others. At the same time as antelope numbers are low, Porcupine (Hystrix africaeaustralis) figures prominently in the diet of the Kalahari lion. Numerically, they can represent as much as 32 % of the annual kill. The porcupine's sharp quills make hunting them hazardous. If the quills cannot be removed from the skin, they can cause severe, and even fatal, infections. In times of scarcity, however, porcupines offer a high fat meal on a limited menu. Kalahari ungulates have evolved reproductive strategies that minimize the risk of predation on the young. Females of wildebeest and springbok herds give birth within a week or two each other. Because the young are very vulnerable for only about the initial month of their lives, and most predators are territorial. Thus limited in numbers, eating only until satiated, the chances of survival for each calf or lamb are much better if births are synchronous than if staggered.

Birdlife

The massive communal nests of the Sociable weaver (up to six metres long and two metres high, weighing as much as 1000 kilograms, and housing up to 300 birds) are so well insulated that they substantially buffer the temperature extremes of the outside air.

Raptors include the Secretary bird (Sagittarius serpentarius), various eagles inclunding the Martial eagle (Polemaetus bellicosus), a gamut of owls, inclunding Giant eagle owl (Bubo lacteus) and an array of falcons, goshawks, kestrels and kites.

Reptiles

caption Namaqua chameleon @ Matt Muir/ iNaturalist Part reptilian predators are the boomslang (Dispholidus typus typus), Cape cobra (Naja nivea), Puff adder (Bitis arietans), and Rock monitor (Varanus exanthematicus albigularis), inclunding geckos, lizards, and skinks. As in a lot of arid areas. Other snakes found in the ecoregion are the Angola garter snake (Elapsoidea semiannulata), the Angola python (Python anchietae), the Black-necked spitting cobra (Naja nigricollis) and the Black mamba (Dendroaspis polylepis). Lizards found here include: Karoo girdled lizard (Cordylus polyzonus); African striped mabuya (Trachylepis striata); Anchieta's agama (Agama anchietae); and Blunt-tailed Worm Lizard (Dalophia pistillum). Geckos found here include the Bibron's thick-toed gecko (Chondrodactylus bibronii). The Namaqua chameleon (Chamaeleo namaquensis) is a representative chameleon found in the Kalahari xeric savanna.
Amphibians

As in most arid ecoregions, the amphibian fauna is not particularly species-rich in the Kalahari, but does include the Giant bullfrog (Pyxicephalus adspersus) that has a omnivorous diet, preying on small birds, rodents, reptiles, and insects. Other anuran taxa present here are the African clawed frog (Xenopus laevis); African ornate frog (Hildebrandtia ornata); Boettger's dainty frog (Cacosternum boettgeri); Red-spotted Namibia frog (Phrynomantis annectens); Mababe river frog (Phrynobatrachus mababiensis); Cryptic sand-frog (Tomopterna cryptotis); Kimberley toad (Amietophrynus poweri); Guttural toad (Amietophrynus gutturalis); Knocking sand-frog (Tomopterna krugerensis);

Arthropods

A backbone of the ecoregion are the billions of brine shrimp, which come to life in the Pans with arrival of the seasonal rains. These crustaceans are the fundamental food source for hundreds of thousands of migratory waterfowl, notably flamingos. A number of scorpion species as well inhabit the ecoregion, of which the two most significant families are the Scorpionidae and Buthidae. Both prey predominantly on insects, and species of the latter often prey on the less venomous members of the former.

Geology

Millions of years ago one of the major rivers of Africa collected the Zambezi and other rivers rising in the north, flowing through this region of the Kalahari. Geologic uplift around 800,000 years ago blocked this flow from reaching the Orange and Limpopo basins, forming an enormous prehistoric lake at Makgadikgadi. Subsequently tectonic uplift in the extreme north of Botswana diverted the Zambezi and greatly restricted inflow to the Makgadikgadi area; as a result the Makgadikadi Pans are instantly strictly a seasonal wetland with the Okavango alluvial fan to the north receiving the residual flow from historic drainages; however the summer wet season finds the Boteti River delivering copious flows here, producing a miracle of emergence of vegetation and wildlife amid the Kalihari Desert. Today's annual flow reaching the Makgadikgadi is less than two % of the Pleistocene level.

Prehistory

This ecoregion is part of the earliest evolution of man, where significant advances in stone tool technology developed prior to migration northward. Recovery of Early Stone Age tools at the Makgadikgadi shores and lakebed reveals vestiges of prehistoric habitation by Homo sapiens and Homo habilis. Late Stone Age tools are as well present, representing additional refined designs of recent man. Field reconnaissance in the dry lakebeds (Hogan. 2008) yielded further surficial specimens of early stone tools and later projectile points. Late Stone Age man would have lived here in huts made of sticks and grass in nomadic groups of 15 to 60 individuals .The women would have concentrated on gathering fruits and nuts, while men created snares of twine to catch springhares emerging from their burrows. Springbok and Eland were hunted by spear and arrow, as the Later Stone Age tools had become additional sophisticated.

Kalahari Acacia-Baikiaea woodlands (Dark Yellow)

Southern Africa bushveld (Light Yellow -eastern part of the country)
Zambezian and Mopane woodlands (Yellow -eastern tip of the country)
Zambezian halophytics (Purple)
Zambezian Baikiaea woodlands (Crimson)
Zambezian flooded grasslands (Light Blue)