According to researchers studying this elusive mammal, sometimes classed as one of the “Shy 5”, in South Africa’s Kalahari Desert, aardvarks prove to be highly susceptible to the warmer and drier climates that are predicted for the western parts of southern Africa, in the future. During the study of a number of aardvarks by researchers of the Brain Function Research Group at the University of the Witwatersrand, all but one of the study animals – as well as other aardvarks in the area – died because of a severe drought, with air temperatures much higher than normal and very dry soil in the area. The study results are published on 19 July in Biology Letters.
“While unusual now, those are the conditions that climate change is likely to bring as the new normal,” says Professor Andrea Fuller, the Research Group’s director.
Dr Benjamin Rey studied the aardvarks as part of his postdoctoral studies. Along with his colleagues, he used the new technology of “bio-loggers” (miniature sensors attached to computer chips and implanted into the aardvarks by wildlife veterinarians), to study the activity patterns and body temperatures of aardvarks living in the Kalahari. The researchers were not to know that during the year of their study there would be a severe drought, which led to the death of the study animals.
Dr Benjamin Rey, lead-author, Brain Function Research Group, School of Physiology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
(Source: 5050 Community YouTube channel)
Aardvarks usually sleep during the day in burrows that they have dug, and emerge at night, to feed on ant and termites, using their long, sticky tongues to sweep up thousands of insects. However, during the drought, the termites and ants, on which the aardvark depends for body energy, were not available.
“As a result, the aardvarks’ body temperatures fell precipitously at night. The aardvarks tried to compensate by shifting their search for ants and termites from the colder night to the warmer day, so that they would not have to use energy to keep warm, but that was not enough to save their energy stores,” says Dr Robyn Hetem, a co-worker on the study. “We believe the aardvarks starved to death.”
The aardvark progressively became skinnier and bonier. They even tried sun-basking to save energy, but many ultimately died. Their body temperatures dropped to as low as 25°C just before they died.
Rey says that this curious-looking creature – described as having the snout of a pig, the ears of a rabbit and the tail of a kangaroo – is much more than just a curiosity to be checked off a bucket list.
The aardvark (Orycteropus afer) is a medium-sized, elusive burrowing, predominantly nocturnal mammal native to Africa. The aardvark is widely distributed south of the Sahara from Senegal to Ethiopia to South Africa, being absent from the Sahara and Namib deserts. It is also present in the Congo Basin, although its distribution in West African rainforests is poorly known (Taylor 2013). It is the only living species of the order Tubulidentata, although other are known. Unlike other insectivores, it has a long pig-like snout, which is used to sniff out food. It roams over most of the southern two-thirds of the African continent, avoiding areas that are mainly rocky. A nocturnal feeder, it subsists on ants and termites, which it will dig out of their hills using its sharp claws and powerful legs. It also digs to create burrows in which to live and rear its young.
The distribution of the aardvark is largely determined by the abundance and distribution of suitable ant and termite species, which it eats. When ant and termites disappear because of climate change, the aardvark will do as well. So, the aardvark’s survival may be threatened by climate change via direct and indirect effects of increasing heat and aridity. It’s current conservation status is considered as Least Concern according the IUCN Red List of Threatened Species™, while the aardvark population trends are not known.
“Many species of African birds, mammals and reptiles use the burrows dug by aardvarks to escape cold and heat, to reproduce, and to avoid predators. They can’t dig these burrows themselves. Without aardvarks, they would have no refuge. Worryingly, they could face the same fate as the aardvark.”
Climate change in southern Africa affects animals through the direct effects of increasing air temperatures and aridity. Wild dogs, for example, reduce hunting activity as temperature increases. But the indirect consequences of heat and aridity may be more pervasive. Disappearance of aardvarks, and with them the burrows that they dig, will have knock-on effects for many other animals.
“Populations of many animals in South Africa are already declining as a result of habitat loss and over-exploitation,” says Fuller. “Climate change adds an additional threat, which may push species to extinction faster. By 2050, the aardvark may not be the only species removed from tourist checklists”.
(Source: University of the Witwatersrand news release, 31.07.2017; Wikipedia; IUCN Red List of Threatened Species™)