ET visited our home last night for some food. His area that we can track him can range up to 1.5 km from home. It is quite amazing that he finds his way back to the house. We are not sure whether this is due to memory or smell??
How ET came to Zuri.
Et the Aardvark came to Zuri, weighing less than 5 kgs.
So what is an Aardvark?
The Latin names of animals consist of two words, describing the genus and the species. That of the aardvark is Orycteropus afer. Above this, all living creatures are classified into “families”, “orders” and “classes”. All mammals fall within the class, mammalia and the aardvark is the only living species within the order Tubulidentata.(To put that into perspective think that all carnivores on earth such as dogs, cats, bears etc fall into the single order carnivora, or the number of monkeys and other primates – including us humans – that are all classified as order: primata).
The aardvark is a truly unique species of mammal on earth. Its name is derived from the Afrikaans that can be literally translated to mean “earth pig”. It has a long slender snout, with huge ears that look a lot like those of a donkey. It has strong front legs with claws that are specially adapted for digging. They are very cautious, nocturnal (night-living) animals that eat mainly ants and termites with their long, sticky tongues. Ant/termite-eating is called: myrmecophagous.
Their most special feature, however, are their teeth which have no enamel or roots and instead, consist o f dentine tubes, densely packed into hexagonal prisms surrounded by columns of dentine. These in turn surround a duct of dental pulp in the middle.
Where do Aardvarks live?
Aardvarks live under the ground in burrows that they dig. Because of this, they are limited to areas in which they can dig; they avoid rocky areas and areas with high levels of ground-water. Another requirement of course, is the abundance of ants and termites for them to eat! They have a wide distribution throughout sub-Saharan Africa.
What is known about their behaviour?
Because they are such shy creatures, very little is known about their behaviour. They hardly ever leave their burrows unless it is completely dark, and even then, do so very cautiously, sitting in the entrance using their ears to listen for potential threats before they come out. Before they start looking for food, they even do a few skips and jumps, stop to listen, and then do another few jumps. Then they settle down and use their very well-developed sense of smell to look for ants or termites. They pick up a trot, moving along in zig-zag movements, and have been recorded travelling distances of up to 15kms per night, although the average is 2-10 kms per night.
Aardvarks mostly live on their own, except when a mother and her young live together. Although they seem to live in a home range and stay within a certain area, it has not been proven that they are territorial and it mostly depends on whether or not they can find food in the area. These animals have well-developed scent glands near their genitals which are pressed into the ground while they are feeding and also when they defecate. These could potentially be used as communication between different aardvarks, but very little is known. It is very rare to see more than one aardvark together in the wild, but in captivity they seem to live happily together.
Aardvarks can live up to 23 years in captivity and reach sexual maturity at two years old and while the female is receptive to the male, they will live together in the same burrow for a short while. The mother is pregnant for seven months after which a single baby is born. The baby has very little hair to begin with but it grows longer later and by the time it is a year old, the legs and lower body are covered in long grey hair. Because they spend so much of their time underground, the colour of their skin depends on the colour of the ground. The baby stays in the den in which it was born for two weeks, and starts to accompany the mother at night while she is looking for food. At three months old, the young also start to feed on insects and by the time the young is six months old, they start becoming independent of their mothers, even if they build their first burrows only a few meters away from mother’s!
They dig different kinds of holes, the first of which is a so-called “camping-hole”, a short tunnel of only a few meters which is used after a night of finding food. They also burrow dens that have longer tunnels ending in a small round “room”. They mostly use these to sleep in and a mother and her young will live in a den together. Some of these have been found that have more than one entrance, and more than one chamber. Then they also dig shallower holes into termite mounds when they are looking for food.
They bury their faeces and seem to have a symbiotic relationship with a certain species of cucumber Cucumis humifructus, known, unsurprisingly as the “aardvark-cucumber” in South Africa. These fruit ripen underground and are then dug up by the aardvark to eat. Aardvarks are the only species that eat these cucurbits and seem integral in their dispersion when they bury the undigested seeds along with their poo.
When an aardvark cannot escape by tunnelling away from danger, it will turn on its back and “attack” with its claws, or stand on its hind feet and scratch with it front feet.
Interaction with other species.
Although many farmers view aardvarks as a nuisance and kill them for burrowing holes which can damage vehicles, and fences, they are considered keystone species in grasslands as they facilitate the existence of many other species. (39 other species have been recorded to make use of their burrows) and other animals that feed on termites and ants depend on the aardvark to open the mounds for them, as they do not have the “tools” to do the digging. These include the aardwolf, bat-eared foxes, and some of the smaller cat species like the black-footed cat as well as civets.
Large predators such as lions, leopard and hyenas will hunt them if they get the chance. They are sometimes also hunted by people either for meat, medicine or because they are seen as an annoyance.
They do however play a significant ecological role and if they are not there to keep termite numbers in check, these could affect the abundance of grass available to grazing farm animals.
Aardvark in captivity.
There are a few zoos that do keep aardvark in captivity and they are easily switched from their myrmecophagous diet to a substitute of hash, eggs, oatmeal and eggs(along with some vitamins!). ET eats pink Pronutro, but as he is free to come and go on the farm, this is only a part of his diet and for the rest he will feed on his natural diet.
In zoos they are sometimes kept in enclosures with other aardvark, or even other species and seem to adapt quite well to this arrangement. Often, however, their enclosures may be lit up at night and darkened during the day so that visitors to the zoo can view their behaviour.
ET was raised by humans, but he is free to come and go as he pleases. He digs himself into a burrow during the day and at might sometimes comes back to the house for food.
Further reading: Biology of the Aardvark by Joachim Knothig
Article written by Marike Kotzé. Marike has a MSc in Genetics from the University in Stellenbosch and a certificate in Science Writing.