An unexpected ecosystem

Something we drive past every day in the African bush, and something that at once stands out to anyone visiting this wilderness for the first time, is the vast amounts of very large piles of dung. This mainly belongs to elephants. Elephants can consume up to 150 kg (300 lbs) of vegetation per day. This, combined with a fast and inefficient digestive system, results in vast amounts of dung.

To a newcomer, elephant dung is usually associated with a foul smell and a sense of disgust. But to me, and, often, to others once they are introduced to the idea, it has a surprisingly sweet scent, one that is distinct to the African bush. This large amount of dung plays a vital role in the distribution of seeds and nutrients as elephants travel vast distances every day, carrying what they have eaten along with them. Undigested seeds then get deposited far away from the parent plant, and nutrients carried within fertilise the soil.

Upon closer inspection, of a pile of elephant dung may reveal quite the surprise, and a whole soap opera plays out on this unexpected stage. Organisms have come to learn that there are many pickings on these deposits and within minutes of them landing, the area comes alive. Observing for a few minutes reveals a whole ecosystem that relies on these deposits. Some acts play out immediately and some take months to complete the cycle.

The first act that we usually notice is the dramatic arrival of the dung beetles. These large beetles have captured our interest from the beginning of time, and they collect and store the dung to function as a stored food source for their larvae, often underground. Male dung beetles roll the dung into balls many times their size and are then chosen by females who will lay eggs on the balls as they are buried. Some dung beetles specialise in stealing the dung balls from others, and this leads to miniature gladiator fights playing out. This can be most entertaining to watch!

Take a closer look and you may notice some sweat bees, gnats, or even a butterfly or two landing on the dung pile. These little insects rely heavily on salt deposits and a source of nitrogen, which they can lap up from a fresh pile of dung. Swarms of little gnats sometimes form a continuous cloud around the dung, all making the most of the short-lived opportunity while it is still damp.

Often unexpected, spiders are attracted to the scent of the dung. Crab and wolf spiders, as well as the personable jumping spiders, show up and often defend the pile from same-species intruders. With the arrival of the gnats and flies, a dung pile becomes a buffet for the taking for these little opportunists. Close inspection can often reveal many spiders scattered across or nearby on the floor.

Once the dung dries a little, usually after a day or so, the boluses are often broken up by the activity of the dung beetles. Eggs of all kinds of invertebrates are laid in the pile of semi-digested plant material. Guineafowl and francolins show up to have a scratch through the dung for any missed seeds or even a juicy bug of sorts hiding away. Hornbills do the same, flipping over pieces of the dung with their large bills. Starlings and waxbills add to the bird groups that make use of this resource.

Millipedes are detritivores (eating decomposing plant material) and are abundant after rains. They are found close to elephant dung in summer. They have a few specialised predators that are not deterred by their poison content, and civets have been noted to shuffle through the dung piles in search of them. One may be lucky to find a large, shiny black ant around, comically named a “ringbum millipede muncher”. These specialise in eating the smaller millipedes often found in dung piles.

Some weeks after the dung has dried up, one may find an animal has kicked over a pile that had been sitting, seemingly unattended. A closer look may reveal that what you’re looking at, is merely a ball of mud where once was a ball of dung. The bolus is hollowed out by termites, and all that stays is the thin layer exposed to the sun, and a latticework of mud inside acting as a scaffold system for the entire removal of the content. The termites could later become targets for baboons , francolins or hornbills looking for an easy source of protein.

What one does not see, is the spread of microscopic spores of fungus through the wind. These mushroom and fungus spores can sometimes remain dormant for years until conditions allow them to grow and break down materials that had not been decomposed. Upon the arrival of the first rains, these spores that landed on old elephant dung deposits often sprout, and suddenly one morning, mushrooms appear. Isolated and on only a select few piles of dung, they are an eye-catcher. They are the last call for the dung that escaped every other onslaught.

The mushrooms are only the fruiting bodies of a much larger organism that works tirelessly to break down organic matter and return nutrients to the soil, allowing the next plant to grow—and eventually become the next elephant’s meal.

Taking a closer look reveals that there is a lot more to a pile of “disgusting” dung than may meet the eye...