Termite Safari
The REAL African mega-fauna
Of all the animals in Africa, the most amazing, and probably least appreciated are the termites, of which there are more than 165 species in 54 genera in southern Africa alone. Coming from termite-deprived regions, North Americans and Europeans cannot easily comprehend the significance of termites in Africa. In the USA, termites are those destructive little creatures that you never see until your house is about to collapse. In between snacking on your walls, they skulk in their invisible nests somewhere underground, shunning the light of day. A more sophisticated American might also tell you that they eat dead wood that falls to the ground from trees. Europeans north of Italy and Americans north of New England have no personal experience with termites.
None of this knowledge prepares the visitor for the African termite. These are not minor esoterica on the landscape. The African termite commands serious attention. To begin with, many species build nest-mounds, and these range from small lumps barely rising above the ground surface to the monster nests of Macrotermes species from whose sides sometimes sprout full-sized trees, and whose domes and spires may rise 15 feet above the surrounding plain. An American tourist coming upon such a mound would very likely be bewildered and puzzled by these odd, out-of-place sorts of hills. What experience would possibly prepare him or her to suspect this huge tumulus was constructed over a human lifespan by tiny, soft-bodies insects?
The most common termites are probably several species of grass-harvesting Trinervitermes. Their hard, two-foot-high clay mounds often dot the landscape by the thousands, like so many evenly spaced orange-halves. In flat landscapes, you can see a little bit farther by standing on such a mound while you scout for game.
Breaking into a mound takes a stout tool, and when you do, tiny, blind soldiers with noses like amber sausage-basters pour out of every gap. They point their noses at you and if you get close enough, shoot sticky threads that smell of turpentine. If you were an ant, you would be in big trouble now, tangled in toxic threads. These soldiers have no functional mandibles, but those of many other species do. In fact, termites have evolved an astounding array of different types of soldiers, endowed with different kinds of weapons, testimony to the fact that termites are preferred chow for many insects, birds, and mammals. Some species of ants, aardvarks, and aardwolves eat little else.
Termites, in their turn, devour all things cellulose, and each species has its own little twist on how it does so and what it starts with. Many species, including Trinervitermes spp., send their voracious armies of grazers out to harvest grass through an extensive system of underground tunnels and accumulate this grass in the outer, dry chambers of their mounds. Break one open, and lawn clippings rain out. Harvester termites are often so abundant that they compete with sheep for grass. Other termites gnaw on wood, either damp or dry, from the protection of delicate covered galleries that they build around each piece they are currently gnawing on.
I collected a little pile of grass clippings to add to my Found Objects collection from a Namibian harvester termite (Baucaliotermes hainesi) whose underground tunnels form a subterranean highway system underlying every square meter of the entire landscape. We used a leaf blower to expose a small part of this enormous system (below).
Each tunnel has a shaft to the surface every half-meter, a central raised “interstate highway” for unobstructed travel, and lateral pockets into which foragers deposit grass clippings for later transport to the nest.
But there are many species of termites that do not digest this harvested material directly. Rather, they pass it through their digestive system little changed, but infected with fungal spores, then build artful, free-form sculptures from their feces, pellet by pellet, like bricks, in their humid underground chambers. The fungus continues to digest the cellulosic material in these sculptural fungus gardens, so that it can be eaten a second time as the fungus breaks down the cellulose.
Fungus-gardening termites have practiced this agriculture for many millions of years. Each huge fortress of Macrotermes is an agrarian village (or megalopolis) full of busy little farmers and an endless conveyor-belt of brood. Each such nest with its fungus gardens is the metabolic equivalent of a cow, with similar impacts on its ecosystem.
Strangely, the colossal towers built by Macrotermes are not its nests, but “only” a ventilation structure for the fungus gardens that lie about a meter below ground. The spire is wind-porous and keeps the fungus-produced carbon dioxide concentration below toxic level for the termites. What an investment of material and labor just for “fresh air!”
The ancestral termites and the extant so-called “lower” termites, like the second-rate ones we have in the USA, digest cellulose within their own bodies, but even they don’t really carry that job out themselves. Their guts are a squirming soup of protozoa, some with quivering cloaks of flagellae, and it is these protozoa that do the actual digestion, or very often, it is the bacteria that live within the bodies of the protozoa. Symbiosis stacked upon symbiosis.
Why all this fuss over the most abundant plant material in the world? Cellulose is exceedingly difficult to digest, but break the code, and an almost unlimited supply of food is available to you. Even most mammals that eat plants digest little, if any, of the cellulose, and if they do, they too enlist the help of microorganisms. What they do well, however, is concentrate all that cellulose in a convenient dung ball for the convenience of the dung beetles and the termites. From the termite’s point of view, the trouble is that being the animals that convert the largest amount of indigestible plant matter into easily-digested animal matter, they invariably become everyone’s favorite lunch. It cannot be otherwise.
Africa is justly famous for its spectacular mammal fauna. People fly in from all over the world to watch large herbivores munch on trees, devour bushes or pluck grasses. No one can fail to be impressed by the migrations of a million wildebeest on the Serengeti Plain, or by a herd of elephants reducing a tree to fibrous dung balls. But all the consumption of plant matter by all the mammalian grazers, browsers, nibblers and munchers pales by comparison with the cellulose that passes through the belly of the termite.
If you stacked up all the herbivorous mammalian biomass, it would be a mole-hill next to the biomass of termites. It all goes to show you: when it comes to Africa, we choose to be astounded, not by true scale and scope, but by our ability to relate. We are mammals too, with mammalian imaginations, mammalian empathy, mammalian insight, and mammalian souls. The soul of the termite is unimaginable to us, so we fail to perceive what big players they are. But perceive it or not, humans and termites have many intersections: whatever we build of wood, thatch with grass, make of cardboard, or put on paper is a meal just waiting for its termites. In Africa, most of human history has been eaten by termites.
[Note: This essay was written after our first return to Africa following the fall of apartheid. Images are from later visits.]
I’m really enjoying learning about the enormity of these small, small things.
You are great at taking the lives of termites and their particular traits into the context of what one can more easily see or comprehend in the bigger world.