6 Jan 2022
Brigitte Weidlich
In Namibia, the large, cone-shaped sand towers in the landscape are among the most popular objects for tourists to take souvenir photos with. Tiny creatures - small, beige-white termites that are only two centimetres long – with the exception of the queen, who is huge compared to her colony - build these mounds.
Termite mounds have a fascinating “inner life”. Millions of termites live inside the mounds. They cherish and look after their home, continue to build them and the seemingly endless network of tunnels, which are mainly used for air regulation. You cannot see anything from the outside - but inside it is buzzing with hustle and bustle.
All activities are regulated by the queen who sets the tone. She and her king take care of the offspring, they constantly produces new eggs that are looked after by the worker termites. The royal couple is almost immobile and has to be supplied with food and their rooms kept clean.
Termite mounds also serve as gardens for certain fungi or mushrooms that the termites feed on,
The so-called termite soldiers provide protection from intruders. These termites are bigger than the workers are and the caste system is strictly regulated. When the soldiers attack, they release a drop of brown, corrosive saliva that spreads between the open lower jaws. When biting, the liquid spreads over the opponent. The secretion is generally referred to as toxic and becomes sticky on contact with air, which makes at least smaller enemies immobile and thus eliminates them.
Organisation is everything
Termites are social insects and are more related to cockroaches than ants. There are around 2,900 different termite species worldwide, four Macrotermes species occur in Namibia: Macrotermes natalensis, M. subhyalinus, M. vitrialatus and M. michaelseni. They build the big mounds.
In the south of Namibia, there are also the grass cutter termites, Hodotermes mossambicus, which build their burrows underground. They feed mainly on grass. In the event of drought and remittance, they can destroy large areas of grazing land, which is a great loss for farmers and their livestock.
Termites are considered a colony. They form an insect state and share the work, the collective does the gigantic amount of work. Every single termite knows exactly what to do and works tirelessly.
The South African journalist, lawyer and hobby behaviourist, Eugene Marais published his first observations on the secrets of termites as early as 1925 under the title "Die siel van die mier" (The soul of the ant). He describes the "founding of the state" as follows:
“A termite state begins its existence the moment the termites fly out. In order to be able to escape their countless enemies, this only happens after rain and usually at dusk. This in itself is a remarkable example of the miracles of instinct. The termites, who have never been outside their burrow, know nothing of enemies when they begin their exciting flight. You know no mortal danger; and yet: in nine out of ten cases they do not fly until the birds are safe in their nests."
After the long flight, the termites drop their wings.
Where the queen lands, a - by the way, underground - nest will be created, which will serve as the basis for the new termite hill, which will be built over the nest from grains of sand and chewed wood-fibres. The worker termites chew up earth (sand) and wood and stick both together with their saliva. This makes the hill solid and stable, and it doesn't wash away when it rains.
Inside the hill, the termites create many branched tunnels and airshafts. They serve as a ventilation system and regulate the temperature. In this way, fresh oxygen penetrates the interior of the termite mound and the temperatures in it remain constant. The higher the termite mound, the more effective its ventilation system.
A distinctive feature of termite hills is the north slope of the one at the top. A group of British-American scientists under Professor Scott Turner
researched termite mounds at the Omatjenne agricultural station in Namibia almost 20 years ago. They found that this slope averages around 19 degrees. This corresponds on average to the zenith angle of the sun and the degree of latitude.
"The slope of the termite mound to the north is likely due to the fact that termites are more eager to build on the warmer, north-facing surface of the mound," said Prof. Turner.
Mushroom gardens for nutrition
Termite colonies have a symbiotic relationship with a Termitomyces fungus. The termites create a mushroom garden inside the hill, which consists of several hundred mushroom combs, which are built from chewed grass and wood and "inoculated" with fungal spores. The Termitomyces culture in a nest of Macrotermes termites helps break down cellulose and lignin into more nutritious compost, which the termites actually feed on. The mushroom garden is a kind of external digestive system to which termites have, so to speak, "outsourced" cellulose digestion, the scientists under Prof. Turner established.
The fungi also play an important role in social homeostasis in Macrotermes colonies and, in particular, help with the water balance of the termite state.
Homeostasis is the balance between the physiological functions of the body;
This makes Macrotermes colonies much more tolerant of arid conditions than other termites, which allows them to exist in drier environments.
Omajovas - giant mushrooms in rainy seasons
Each year in Namibia, termite mounds produce large white mushrooms on the outside of the mounds known as omajova during the rainy season and are highly valued as a delicacy. They taste great. Read our article by Ron Swilling It’s omajove time. https://namibian.org/news/nature-and-environment/its-omajove-time
Termites are climate protectors
The vegetation near termite mounds is denser and lusher. The ability to break down organic matter makes termites very important for a functioning ecosystem. In the rainforest on the island of Borneo, researchers found that the work of the hardworking insects helps to keep the forest floor moist. In times of drought, more young plant seedlings survive in the moist soil. This is how termites fight the consequences of climate change in the rainforest.
Similar conclusions have been reached in Namibia. Termites burrow through soil and grass and aerate the soil, allowing more rainwater to penetrate the soil. Termite droppings, combined with ventilation, create fertile soil with a higher nitrogen and phosphorus content. Grasses and bushes near termite mounds grow better, benefiting antelopes, zebras and buffalo, as well as farm animals such as cattle and sheep.
Keep your distance while building
Due of their preference for cellulose, being wood, some termite species are unpopular with humans. They erode wooden beams and floorboards. Many homeowners have had nasty surprises when the wooden floor collapsed and thick ceiling beams became rotten. In Namibia, farmers have a story or or two about it. Therefore, a suitable distance between termites and buildings in the countryside is necessary, as is a regular check of the house and yard to see whether termites have "moved in". Experts can then remedy the situation with chemicals.
A termite mound is not only a pretty photo opportunity but also a small ecosystem and not all of its secrets have been revealed yet.
Sorry, we can’t seem to find any matches for your search. Have a look at our popular searches below.
