The Arid Namib

An amazing array of plants and animals survives in the Namib, the world’s oldest desert. They’ve had fifty million years to evolve cunning ways to cope with the heat and harvest water from the fog that often blankets this unique coastal desert.

Produced by NHNZ

When the ancient supercontinent of Gondwana broke up, the Atlantic Ocean opened up between South America and Africa. By 50 million years ago, a cold ocean current was flowing up from the icy south Atlantic along the coast of what is now Namibia. Called the Benguela current, it had a profound effect on the landscape. The icy current cooled the air at sea level, which was blanketed by a layer of warm air. This classic ‘inversion layer’ prevented the cool, moist air at sea level from rising and forming rain clouds. The Namibia coast was transformed into a vast desert that stretched up to 60 miles inland.

But the Namib Desert is far from barren. Because it is tens of millions years old (the Sahara by comparison is a mere 5,000 years old) evolution has had time to shape an array of mutant plants and animals that can survive and even thrive in this harsh place.

Isolated from other landmasses by continental drift for 100 million years, a unique group of African mammals evolved. Scientists have only recently realized that all these ‘Afrotheria’ evolved from single rat-like ancestor. Over time, it morphed into creatures as diverse as desert elephants and termite eaters like the aardvark and the utterly blind golden mole.

Termites are the key to the survival of many creatures in the Namib. The bat-eared fox and the aardwolf rely almost exclusively on termites for food and water. Aardwolves are actually bizarre mutant hyenas, descendants of early hyenas that invaded Africa once it joined up with Eurasia. Faced with stiff competition from other carnivores, the ancestor of the aardwolf, like so many animals in the Namib turned to the inexhaustible supply of termites.

Termites could also be the key to understanding on of the greatest mysteries in the natural world. On the arid plains of the Namib, hardy grasses cling to life. But these grasslands are pockmarked by entirely barren patches known as ‘fairy circles.’ Dr. Norbert Jürgens believes that these circles are created by sand termites. Even in the searing heat, the sand in the middle of the bare patch holds onto what little rain falls. Because the termites are prone to drying out, they forage for grasses in ever expanding circles around the moist sand in the center of the fairy circle.

Water also comes from an unexpected source: fog. When moist air blows in from the mid-Atlantic, the cold water of Benguela current causes dense fog banks to form and many miles inland. In such a dry place, this added moisture is the difference between life and death for many of the mutants that have evolved to eke out a living in The Arid Namib.

Episodes From This Series

Borneo

48 minutes / 2014

Japan

50 minutes / 2010

Brazil’s Cerrado

50 minutes / 2010

Australia

50 minutes / 2010

New Zealand

50 minutes / 2010

Costa Rica

48 minutes / 2014

Africa’s Albertine Rift

1 hour / 2014

China – Roof of the World

1 hour / 2014

Western Ghats and Sri Lanka

1 hour / 2014

The Arid Namib

1 hour / 2014

Madagascar

1 hour / 2010

Africa’s Rift Valley lakes

1 hour / 2010