Deserts might be renowned for their arid and hostile characteristics, but they are home to some incredible plants that have developed strategies to find and use the very last droplet of water.
Image: DW/B. Osterath
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What is a desert? Per definition, the answer to this question is simple. They are areas of land with little to no flora. Though they are dry, they are not all hot. Take Antarctica, the largest desert in the world. Because it's so cold there, it is just as dry as the Sahara, the biggest hot desert on the planet.
Generally speaking, when we think of a desert, we think of inhospitable, sandy and furiously hot regions. We think of towering dunes, sand storms and temperatures that bake by day and chill by night. One thing we are unlikely to think about are the plants that thrive in these unfriendly conditions. But they are out there. In the Sahara alone, there are 1,400 different plant species. Some of them, cacti.
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Green giants
Carnegiea gigantea is one of them. It is a succulent plant, which means it can retain its own water supply. This cactus grows in the North American Sonoran Desert and can reach heights of 16 meters, collecting enough water inside to keep it moist for a year.
To do this, it relies on a root system that lingers just below the surface. That's not their only trick, for these prickly giants can live to a ripe old age of 220. When they hit 40, the age at which life reputedly begins, they start to bloom. At that stage, they're 2.5 meters tall. By the time they hit 65, they've soared to heights of six meters.
Image: Imago/H. Lange
As if by magic
A much smaller and unlikely looking desert survivor found in North Africa and the Sahara goes by the name of the Rose of Jericho. With its olive green foliage and white flowers, it grows to around 10 centimeters. When the rainy season ends, it folds in on itself so consequently that it almost becomes a ball.
In this state of hibernation, it is brittle and more brown than green, and could easily be given up for dead. But it can just as easily be resurrected if put in water. Its cells absorb the liquid and the plant unfolds, leaving it looking almost as fresh as a daisy. Its dry casing serves to protect the seeds which, in the event of a heavy downpour, quickly begin to germinate.
Image: picture-alliance/blickwinkel/P. Fuchs
Dig, dig, dig
Once upon a time a single Acacia stood in the middle of Niger's Ténéré desert. It was the only tree for 400 kilometers, and was considered the most isolated one in the world.
For decades, it was the sole specimen, offering travellers a shady place to rest, but also posing questions about its tenacity. In the winter of 1938/39, those who wanted to know how the tree managed to survive, started to dig a shaft nearby. They spent a long time excavating hot sand, but once they got to a depth of 30 meters, they hit upon the explanation: groundwater and the tree's roots.
So-called taproots are strong and grow vertically allowing plants to grow on rock cracks, not only in the desert. Oaks, pines, dandelions and carrots also have taproots.
Image: Imago/imagebroke
In the cool depths
Other plants more or less grow under the earth allowing just their tip to peep out of the ground. Fenestraria, which is also known as baby toes or window plant is a perfect example. The waxy leaves of this plant, which grows in Namibia, are sometimes completely covered, with their roots penetrating deeper into the ground.
The tips of their club-shaped leaves form a kind of window, so-called because it is transparent and conducts the light from above into the darkness of the earth below, ensuring that the plant grows.
How species survive in the Namib desert
Survive and thrive in the Namib desert
Scorching hot by day, freezing at night, scarce water and food supplies - the Namib desert in southern Africa is a hard place to live. But these animals have found ways to cope with the hostile conditions.
Image: R. Dückerhoff
Take what you can get
Ostriches do not mind the hot and barren African desert. The flightless birds can raise their body temperatures to stop them sweating and reducing water loss. They get all the water they need from the plants they eat. They also swallow small stones, which grind food in their stomach. Their intestines can handle things that other animals can't digest.
Image: picture-alliance/Arco Images/C. Hütter
Keeping cool in the heat
Gemsboks also raise their body temperature on hot days - up to 45 centigrade (113 Fahrenheit). A network of small blood vessels in their noses cools the air they breathe, and that keeps their brains cool too. The gemsbok's underpart is white, reflecting the heat radiating from the ground. They get fluids from water-rich foods such as roots, tubers and the tsamma melon, which grows in the desert.
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Pick a color
Too hot? No problem for the Namaqua chameleon. It simply changes its color to become lighter and reflect more sunlight during the heat of the day. In the cooler mornings, though, they are black. Their tail is quite short compared to other chameleons. They don't do a lot of climbing in the desert, but they do climb on rocks and small bushes to get away from the hot sand in mid day.
Image: R. Dückerhoff
It's cooler higher up
The Namib Desert dune ant's legs are about five millimeters long. They lift the ant to a height where temperatures are up to ten centigrade (50 Fahrenheit) cooler than directly on the sand surface. It gets its fluids from honeydew, excreted by plant-sucking scale insects. Even though the ants look conspicuous on bare sand, predators shrink away from eating them: formic acid spoils the meal.
Image: DW/B. Osterath
Going underground
The Namib sand gecko (Pachydactylus rangei) avoids the heat of the day by digging burrows and only coming out at night. Its large eyes help it to find prey in the dark. Its webbed feet are perfect for burrowing and walking on sand. The gecko's skin is translucent so that some of the internal organs can be seen. Its color allows very good camouflage in the sand of the desert.
Image: R. Dückerhoff
Night dancer
The Dancing White Lady Spider (Leucorchestris arenicola) also likes to avoid the sunlight. It constructs a 0.5 meter deep burrow out of sand and silk where it hides from the heat. As the spider only comes out at night, it doesn't need sun protection, hence its white color. When mating, the males tap their foremost legs on the sand, giving the species its "dancing" name.
Image: R. Dückerhoff
Easy does it
"Go slow" is the motto of the Namib Dune Scorpion (Opistophthalmus flavescens) when it comes to metabolizing. The animal doesn't need much energy and can wait for months until the next meal arrives. The oxygen transport system in the scorpion's blood is different from ours and isn't hampered at high temperatures - perfect for life in the desert! It digs three meter deep burrows to live in.
Image: R. Dückerhoff
A nose like a shovel
The sand in the Namib dunes is so fine that some animals swim through it – as if it were water. They don't even have to dig. It's true for this shovel-snouted lizard. The shape of its head allows it to move through sand without resistance. It's good for escaping from predators where cover is sparse. Its nostrils face backwards and have a cartilaginous flap to prevent sand from entering.
Image: R. Dückerhoff
A life in the sand
The FitzSimons' Burrowing Skink can also swim through sand. It spends its whole life in the sand of dunes, where is searches for food, such as small insects. It detects its prey by feeling for vibrations created by the insects when they move.
Image: R. Dückerhoff
Hide and eat
This snake, the venomous sidewinding adder, has found the perfect way to catch prey in the Namib desert. It burrows itself in the sand, leaving only its head sticking out – but it looks just like the sand. It moves with characteristic side-winding movements through the fluid sand, hence its name. Sidewinding allows the snake to move over hot sand without overheating.
Sociable weaver birds meet most of their water needs through their diet, which consists mainly of insects. They build huge nest structures, housing hundreds of birds of several generations at a time. The chambers inside the nests provide shade and are cooler than the outside, whereas the central chamber retains heat and is the ideal place for night time roosting.
Image: R. Dückerhoff
In all shape and sizes
Beetles are central to the food supply in the Namib desert. They feed on detritus, dead organic matter from plants which is blown into the desert by wind. During early mornings, they collect water droplets from fog. Other animals feed on the beetles to get their water. About 200 species of beetles roam the Namib desert. Most hide in the sand.
Image: DW/B. Osterath
Harvesting water
The fog basking beetle has a peculiar way of collecting drinking water in the Namib desert. In the morning, it runs up the dunes and does a headstand. Fog condenses on its back, and droplets run down towards its mouth. They can drink up to 40 percent of their body mass on one morning. The species is also known as the head-stander beetle.
Image: picture-alliance/Wildlife/M. Harvey
Playing dead
Get eaten by other animals? No way. This weevil has other plans. When it is threatened, it drops on its back and plays dead, hoping its predators have no appetite for dead, dried-out beetles.
Image: DW/B. Osterath
Life under rocks
There is life everywhere in the Namib desert, even under rocks! Cyanobacteria grow there. Enough sunlight penetrates this white rock for the bacteria to perform photosynthesis. In the blazing sun, though, they die.
