Many animals are present temporarily, like migratory birds or even wildebeest, while insects and rodents are tiny and fastidious. Aardvarks on the other hand are ancient. Indeed, there are fossil records of them from 5.4 million years ago. Why are aardvarks important? Because their behaviour and physical impact on the land has been shaping the desert for longer than we can ever imagine. That’s 5.2 million years before our species evolved and more than twice as long as any human-like animal has even existed.
Builders not transporters
One thing that sets animals apart from plants is their ability to move. This means our world’s wildlife can do several things to maintain a habitable planet. First, they can transport energy from one place to another. Migration is the ultimate tool that enables bulk transport of energy but it isn’t the only way animals impact the land. The other is the ability to build and construct.
In previous blogs I’ve talked about the effect that spiders have on the environment and their indefatigable role in recreating broken ecosystemsHow ecosystems function An ecosystem is a community of lifeforms that interact in such an optimal way that how ecosystems function best, is when all components (including humans and other animals) can persist and live alongside each other for the longest time possible. Ecosystems are fuelled by the energy created by plants (primary producers) that convert the Sun's heat energy More. When we think about ecosystems, we always have to think in terms of different scales. There are ‘ecosystem engineers’ at the bacterial level too. Imagine ecosystems like infinite nested boxes where each contains a smaller subset of the ecosystem that works in just the same way.
When we allow existing wildlife to go extinct, we reverse millions of years of process. As long as there are still some left though, animals can help us reverse this fast.
When scientists talk about animals as ‘ecosystem engineers’ though, they are usually referring to the largest, because we are biased towards our own world view. We see things as important because they are as big as us, or on a scale similar to what our species constructs.
Nonetheless, large animals do create the foundations for the patterns in those smaller-scale boxes to evolve. They are like the makers of crucibles. Therein life can thrive at the scales we need to create our soil, water and climate. Without aardvarks many of the other species of animal – and indeed humans – will find it hard to make a living.
Why are aardvarks particularly significant?
Aadvarks are big. They weigh about 60 kg (140 pounds) and are a couple of metres (7 feet) long.
But it’s not just their size that matters, it’s also because of what they do and how they do it. They are not migratory, they are resident. Their impact has been forever. It’s not that intensive but they have built deeper foundations than almost anything else that exists around them. Aadvarks have been eternal, enduring and unremitting.
This prehistory makes them just as integral to the landscape of today as a rock, sand dune or mountain. This fact is rarely acknowledged in conservationWhy is animal conservation important? Animal conservation is important, because animals are the only mechanism to create biodiversity, which is the mechanism that creates a habitable planet for humans. Without animals, the energy from today’s plants (algae, trees, flowers etc) will eventually reach the atmosphere and ocean, much of it as carbon. The quantity of this plant-based waste is so More science, where animals are seen as an addition to the landscape, not necessarily part of it. It’s more common to read about this in Indigenous science.
‘There is Law and knowledge of Law in stones. All law-breaking comes from that first evil thought, that original sin of placing yourself above the land or above other people’.
Tyon Yunkaporta, Sand Talk.
Previously I wrote about how the epic migration of Monarch Butterflies couldn’t be explained by their biology and that ‘they contributed to the creation of an ecosystem for themselves in much the same way as water molecules erode a path through rock’. As sure as a river carves a canyon to ensure water flows on a predefined route, animals have shaped the landscape to match their movements, behaviour and needs.
It’s only taken a few hundred years for people to wear down the marble steps on Italy’s tower of Pisa. What do you imagine was the effect of aardvarks walking circuits around the landscape and digging the soil over millions of years?
The impact of aardvark burrowing
When you look at a desert you might only see sand, bushes and grass. An ecologist will see a mosaic of sweeping and discernible patterns in the undulations of geology and dunes – places where moisture can become trapped. Landscapes, however, are not ecosystems without animals. It’s animals that fill these damp depressions with life-giving nutrientsEnergy and nutrients are the same thing. Plants capture energy from the Sun and store it in chemicals, via the process of photosynthesis. The excess greenery and waste that plants create, contain chemicals that animals can eat, in order to build their own bodies and reproduce. When a chemical is used this way, we call it a nutrient. As we More. It’s animals that transfer(of nutrients) the thing that sets animals apart from plants, is that they can move. Some of the biggest migrations on Earth every day, are the movement of insects like caterpillars, from the stem of a plant to a leaf and back, before turning into butterflies and transferring the energy elsewhere. Large-scale migration of grazing animals and migratory songbirds moves More, amplifyAmplification (of nutrients and energy). Animals consume plants and other animals and in doing so, reintroduce important energy-containing nutrients back into the environment, at even higher concentrations and in patches. Amplification of energy is driven by migration and happens at every scale, from insects moving daily in and out of your vegetable patch, to African wildebeest herds and the seasonal More and concentrate resources. Piled into places where and when other animals can expect to find them, they offer certainty for survival.
Aardvarks are undoubtedly significant concentrators of nutrients. They feed predominantly on ants and termites, and they defecate the waste into grassland. This happens in patches, not evenly across the landscape.
They also have another significant behaviour: burrowing. Just like in humans, the need to find a place to sleep forces us to return to the same places, over and over again. The movement of aardvarks in a landscape isn’t random, it’s based on centuries, maybe thousands of years of work. Burrows and foraging digs are a predominant feature of the landscape and this has led to aardvarks being called ‘engineers’. As you can imagine, the burrows are massive!
#1 The magnitude of aardvark impact
Research shows that aardvarks tend to use a single burrow for about 5-9 days before either renovating or creating a new one.
Stephanie Anne-Martin at Nelson Mandela Metropolitan University collected data from just under 129 burrows over 40ha [3]. However, when foraging holes were included, the number of ‘digs’ increased to nearly 2,000.
The image (below) is from the Save the Aardvark website and it shows the number of aardvark holes in a 30ha patch of desert (about 10% of an aardvark’s territory) in the Kalahari. It’s not clear whether these are burrows or foraging holes. Nonetheless, it illustrates the magnitude of the effect aadvarks have, in their habitat. There won’t be much ground left untouched by their nocturnal peregrinations.
#2 The scale of aardvark impact
Distribution of Aardvarks in southern Africa is patchy. Where they do occur, such as in the Kalahari, there might be perhaps eight animals for every ten square kilometres and suitable habitat probably covers a third of the country. Mostly they are occurring in flat or gently sloping areas of semi-arid desert and savannah, which are the predominant landscape types throughout subsaharan Africa.
There isn’t much information at all on populations which might be 10,000 or more animals in South Africa. This would equate to an area of about 12,500 km2, or about 3.3% of suitable habitat. A few percent might not seem significant but in percentage terms, it’s equivalent to half of all the arable food production land in South Africa.
The scale of impact that aardvarks have on the landscape is significant, especially when combined with the magnitude of their effect.
#3 The intensity of aardvark impact
Burrowing aardvarks continuously dig soil for foraging and burrowing. In preferred altitudes and habitat about 140 holes have been counted and the amount of soil turned over just for foraging can be almost 6 tonnes per ha [3]. This means the average foraging aardvark might be disturbing 180 tonnes of soil at the surface each year. Add in refuge burrows and this increases to by several times that volume.
In short, aardvarks are by far the biggest soil engineers in the ecosystem. But they are not alone. There is another dimension to the aardvark tale. Other animals like porcupines, bat-eared foxes, meerkats and so on, can’t / don’t always dig their own burrows, preferring to use holes made by aardvarks. The rare Blue Swallow nests inside aardvark burrows. The intensity of impact aardvarks have on the landscape is amplified by their connection to these other animals.
Because animals have to return to burrows each night, their impact intensifies over preferred areas, creating the patchiness needed for smaller creatures to find reliable food. They have surprisingly small home ranges. They forage within only about 3km2 but they can travel 2-5 km, and even up to 30 km, each night [1].
And they hunt all night. By continuously producing turning over the soil layer, they affect hundreds of square metres of habitat – something they’ve been doing for millions of years.
The biodiversityWhat is the definition of biodiversity? When we ask, what is the definition of biodiversity? It depends on what we want to do with it. The term is widely and commonly misused, leading to significant misinterpretation of the importance of how animals function on Earth and why they matter a great deal, to human survival. Here I will try to More value of aardvarks
Take any large and reasonably abundant animal and you’ll find hardly a patch of ground untouched. The impact they have might be invisible but it is still significant. Aardvarks are one of the hardest animals to see because they are largely nocturnal but their burrowing effect is huge!
To assess the conservation status of animals using distribution maps and numbers belies their nature and importance in a landscape. In global conservation listings aardvarks are ‘least concern’ because they are widespread. They are vulnerable to extinction in all settled areas and extinct in many areas with a high concentration of people. That’s not the point. They are integral to the integrity of entire landscapes and the magnitude, scale and intensity of their impact is enormous.
Aardvarks are creating the structural, moisture and nutrientA substance that contains the raw materials for life. At a chemical level, these are contained inside compounds that are absorbed into the body and essential energy-containing molecules are extracted, so that energy can be transformed into other chemical processes that use the energy for living. More conditions for ants and termites to thrive. They promote vegetation growth that insects break down with the help of fungus and disseminate back into the soil, alongside microbes.
Aardvark-like impacts in your own back yard
Don’t imagine this story is unique to Africa. If your landscape lacks abundant megafaunaThe largest animals that represent the top of the trophic pyramid. These are the final building blocks in ecosystem structures for maximum entropy production. Megafauna can be measured at any spatial scale. The largest animal that ever lived on Earth is the Blue Whale. In a grassland, spiders could be considered megafauna The term is generally reserved for animals larger More, question whether you are losing what you need to survive. What resident animals used to exist where you live?
Here is an extract from Isabella Tree’s Wilding. Faced with an outbreak of weeds on a farm in Sussex (UK), they waited to see what would happen. Traditional livestock were introduced a long time ago. The role they play isn’t that different to aardvarks … it was their relationship to ants and insects that saved the day.
“… those three years of thistles had proved a gift. The prickly cover had protected other butterflies, day-flying moths and fellow invertebrates … Though Exmoor ponies and pigs were partial to thistles, they hesitate to wade through robust swathes of them and tend to nibble only at the fringes. Protection from the hooves of herbivores gave an added bonus to anthills … the worker ants cut down thistle and grass stalks to add structure to the new mounds … you can tell where the outbreak of creeping thistle once was, from the density of anthills’.
Three years it took to restock with ants. The result? A more resilient landscape that captures more moisture and where more and more animals can respond to natural variations in the environment and ecology. The starting point was allowing some megafauna to recreate natural processes, to step back, and not interfere.
When we allow existing wildlife to go extinct, we reverse millions of years of process. As long as there are still some left though, animals can help us reverse this fast. The results are nothing short of miraculous. If we’re going to conserve wildlife we have to start telling these stories.
Do you want to support the conservation of aardvarks?
Save the Aarvark is taking donations for its work, which is looking at how to alter bush management, to give the animals a better chance of survival. Aardvarks here are quite well protected but scientists are finding that climate change is affecting their ability to find ants. If aardvarks disappear, there will be cascading losses throughout the region.
https://savetheaardvark.com/
References
- Taylor, Andrew (1998) The ecology of the aardvark, Orycteropus afer (Tubulidentata – Orycteropodididae). Dissertation (MSc)–University of Pretoria, 1998.
- Endangered Wildlife Trust (2018) Orycteropus afer – Aardvark. The Red List(of endangered species). A list of current conservation status for all the world’s known species. The list is administered by the International Union for the Conservation of Nature (IUCN) and the data is fed into by national and international organisations to be continuously updated. More of Mammals of South Africa, Lesotho and Swaziland.
- Martin, Stephanie-Anne (2017) The aardvark as an ecological engineer in the Eastern Karoo: dig patterns and emergent processes. Submitted in fulfilment of the requirements for the degree of Master of Science in the Faculty of Science at the Nelson Mandela Metropolitan University April 2017.
