Biodiversity in the Okavango Basin

An ancient baobab tree stands among other trees in Botswana’s Okavango Delta, a UNESCO World Heritage site that sustains critically important populations of threatened and endangered species. Every year, trillions of liters of life-giving water floods this part of the parched Kalahari Desert, transforming it into a tapestry of habitats that support phenomenal biodiversity and a thriving ecosystem—forming a landscape of exceptional beauty. Rich biodiversity like this is an indicator of overall ecosystem health, and the wildlife levels found here, especially in such a dry region of Botswana, are a rarity across Africa.    

Shrouded in dust, an enormous herd of Cape buffalo thunders across a floodplain of the Okavango Delta. Buffalo shape the landscape here as they graze and stomp through undergrowth, keeping spaces open for predators to hunt. A change affecting any one species can have a profound impact on another, potentially changing the entire ecosystem. Certain plant life can only be pollinated by specific insects or birds; should those species disappear, so will the food source for herbivores like buffalo, and their decreased numbers will, in turn, mean buffalo will no longer support or shape the habitat for other animals.

A spider sits in its dewy web near an Angola source lake for the Cuanavale River, one of the rivers that feeds the Delta. While the Okavango Delta is an ecosystem in balance, it is part of a much larger system that spreads the length of the Okavango River Basin, beginning with the source waters in the vast miombo forests of Angola’s highlands. To determine the health of this wider ecosystem, along with the impact any changes could have on the Delta, the National Geographic Okavango Wilderness Project has been surveying biodiversity along the rivers with a focus on an area in southeastern Angola. To support the continuation of this research, De Beers has joined National Geographic through the Okavango Eternal partnership. Together their goal is to help ensure that protected status, similar to that  which safeguards the Delta, extends across the entire Basin, through Namibia, and into Angola.

A pied kingfisher, mid-snack, in Angola. These birds feed on fish, crustaceans, and large aquatic insects, often plunge-diving headfirst into the water. Like many wetland birds, the pied kingfisher is  an important indicator of ecosystem health—more abundant prey means more birds. If the health of the system declines, then birds will simply “choose with their wings” and move to other areas where they can find more food. The presence of pied kingfishers in Angola, Botswana, and along the rivers of the Okavango River Basin is also a sign of the interconnected nature of this complex ecosystem. The birds’ pervasiveness across the entire Basin indicates plenty of good habitat from the source waters to the Delta. Protecting all of this habitat is crucial as much of the Okavango River system is currently under threat from deforestation as land is given over to practices like commercial agriculture.

A lion surveys open savanna, host to abundant herds of prey. Healthy ecosystems like the Delta have a significant number of apex predators as explosions of plant life farther down the food chain are able to support greater numbers of herbivores, which then sustain larger predators. Just as the Delta draws impressive mammals like lions, the big cats, in turn, attract international tourists who provide around 12% of Botswana’s annual income, which supports many livelihoods. Decades of conflict in Angola, where the Delta’s source waters are located, have led vast numbers of iconic large mammals, including lions, buffalo, and especially elephants, to move farther down the Okavango River Basin―where the ecosystem there can’t always support their increased numbers—throwing the wider ecosystem out of balance.

African savanna elephants are a keystone species that shape the habitat around them. Feasting on shrubs and uprooting saplings, they keep the landscape open for plains animals to roam, literally paving the way for biodiversity to take root and blossom. Once they’ve laid the foundations, elephants become nature’s gardeners, keeping plant growth under control and habitats shaped. But too many elephants in one place can overwhelm the balance of the ecosystem; the massive animals require up to 135 kilograms (300 pounds) of food daily, which can exhaust the resources a habitat is able to provide.

Namibian scientist Frowin Becker casts a net to collect fish samples along the Cubango River. Now supported by Okavango Eternal, experts within the National Geographic Okavango Wilderness Project believe that elephants will play a key role in connecting the relatively unknown ecosystems in Angola to the flourishing Delta in Botswana. These ecosystem engineers can use their credentials to pave a “wildlife superhighway” that allows other species to move freely across the entire Okavango River Basin. Governments, conservation organizations, and local communities have already protected areas of land to allow for elephant migrations, but the partnership’s aim is to specifically protect the life-giving waterways, providing the security elephant herds need in order to once again traverse their ancient migratory routes.

Decades of war in Angola forced elephants out of that country and down into Botswana―towards the safe, protected haven of the Okavango Delta. Too many elephants in the south of the Okavango River Basin and almost none in the north is another factor tipping the scales of this ecosystem. De Beers has experience with a very similar situation: Through its Moving Giants initiative, De Beers is in the process of translocating around 200 elephants from Venetia Limpopo Nature Reserve in South Africa, where safe conditions have led to too many elephants, to a landscape largely devoid of elephants in Mozambique, where the first family groups are settling in well. Having managed nature reserves and conservation programs for nearly 130 years, De Beers is bringing its conservation expertise to help support Okavango Eternal’s biodiversity goals.

A vervet monkey inspects something it’s never come across before—a remote camera. Decades of war have left Angolan wildlife skittish and distrustful of humans, making documenting them and studying their behaviors very difficult. Okavango Eternal will support  the National Geographic Okavango Wilderness Project’s ongoing research, which includes a mutually beneficial remote camera project collaboration between researchers and surrounding communities. Cameras are provided to local communities, and residents there set them up in remote areas in the hopes they will snap some elusive species. Communities are paid incentives for these photographs, and are updated regularly on why their discoveries are significant. This collaborative approach builds awareness and encourages local people not to disturb habitats with damaging practices, such as using fire to flush animals out into the open for hunting.

Near the village of Tempué, Angola, a chameleon perches on the finger of Timotéo Julio, a local herpetologist. After seven major biodiversity surveys, the NGOWP has discovered a host of species new to science, especially in Angola, which has recognized the need to study these species and their habitats long-term. Okavango Eternal is funding training and ongoing research of other local scientists and students across Botswana, Namibia, and Angola, covering study areas such as botany, ornithology, and biology. These experts’ findings will reinforce the need to preserve and protect the biodiversity that supports the Okavango Delta. 

Explore Okavango Eternal here.