BIG STORIES about little things – The Namib desert

This is the first in a series by Joh Henschel of EnviroMEND about the Namib Desert, a Pandora’s Box where small is big. Its wonders have many forms, some of which are easily overlooked tiny creatures and processes.

Photographs by Joh Henschel

Floccinaucinihilipilification is a big word that stands for nothing. The dictionary meaning is rather more subtle: regarding something to be of no value.

Is this not what deserts are often considered to be? They are certainly big and full of things we initially cannot understand, just like our big word, but are they empty and valueless, just what our big word expresses? Look closely at the Namib Desert, and you will find it is full of little things that have meaningful big stories that reveal this desert’s real values.

The gravel plains of the Central Namib appear to be one of the most barren areas in the world. Yet they harbour a great richness of creatures. It is here where the biodiversity of some groups of beetles, fishmoths, sunspiders, scorpions and lizards is an order of magnitude greater than in any hyper-arid desert habitat in the world (annual rainfall is normally 0–20 mm, an except being 2011, when over 100 mm fell).

For example, at a single location over 40 darkling beetle species occur, whereas similar sites in the Sahara may have only four species. Most of the Namib species are endemic, occurring only here and nowhere else.

Surprisingly, for many small creatures, the desert is a moist place. How come? The Namib has little water and it rarely rains. But let us examine the water that there is and what this implies. Moist air from the ocean is blown far inland. When the desert cools off at night, dew condenses from this moisture. Sometimes, the moisture builds fog, and thick clouds blanket the desert. Dew and fog moisten stones, soil and plants and, for brief moments, there is relief from dryness.

Namib beetles are famous for their ability to use fog, and about one-third of the darkling beetles do so. The fog-basking that is performed by only two Onymacris species has become an iconic Namib beetle activity. During cool, foggy nights these normally diurnal beetles crawl laboriously up the dune and perform a headstand. Water droplets accumulate on the body and run down into the mouth.

Palmato gecko

In a single drink, a beetle obtains water equivalent to an eighth of its own body weight. Other beetles drink water from surfaces. Sidewinder snakes and palmatogeckos drink fog water from their bodies. Lepidochora beetles dig trenches in sand where fog water accumulates and they drink. Other animals drink droplets off vegetation or lichen.

Even without fog or dew, the desert soil takes up atmospheric moisture, giving brief respite to Lilliputian plants and animals. For instance, this enables blue-green algae, aka cyanobacteria, to thrive under quartz stones where moisture lingers and light penetrates, allowing photosynthesis.

Desert lion

Some insects have an uncanny ability to collect water from moist air. Now these are the true geniuses of the desert. Beetle larvae, wormlike creatures that shuffle through sand, can do it. So can silverfish.

They produce a certain kind of salt that takes up moisture from the air, and use an extremely strong pump to extract the water from the salt, surprising for such delicate animals. This mechanism is, indeed, one of the most special abilities of Namib creatures.

Cape Cross

The toughest tiny diehards in the most parched terrain are sometimes rewarded by the unthinkable – rain! Every few years the desert is transformed as if by magic wand, and the jewel box overflows in luxurious green, dotted with many bright flowers, busy bees, and population explosions of scampering beetles and flurrying birds.

The above is only a small selection of the myriad of wonders of the Namib. Observant people are rewarded by amazing experiences in the most unlikely places.

This article appeared in the September 2011 edition of Flamingo magazine (Air Namibia's in-flight magazine).