Among the shrublands of Africa lives a fascinating mesocarnivore that is named after two other, more popular, species. However, the aardwolf is not related to either the aardvark or wolf, but rather an ancient member of the Hyaenidae, or hyena family. Even though this smallest member of the family shares some physical and behavioral characteristics with the well-known spotted and striped hyenas, their specialized diet sets them apart from their cousins.
Traditionally, evolutionary biologists believed aardwolves were not related to hyenas, but rather their coloration simply mimicked striped hyenas to avoid predation. However, modern genetic research has concluded that aardwolves are not only hyenas but are the longest-living member of the family, diverging from the other species around 10 million years ago. The most striking difference between other hyenas and aardwolves is their petite size.
Being the smallest hyena species, aardwolves only stand around 20 inches tall and measure up to 2.5 feet in length, with their densely furred tail adding another 12 inches. Adults weigh between 15-30 pounds. Like their striped cousin, aardwolves have a brown or yellow base fur color with black vertical lines streaked along their thorax and abdomen, and diagonal stripes on their legs. A long, black mane runs the length of their body along the spine and is erected when danger is near, which increases their visual size up to 70% to fool potential predators!
Contrary to other hyena species, aardwolves have five toes on their front paws and four toes on their hind paws. All other hyenas have four toes on both front and back. This unique characteristic earned them the generic name Proteles, which translates from Greek to mean “complete in front”. Their Latin-derived species name means “provided with a comb”, referring to their long mane.
Aardwolves reside within two distinct locations in Africa. The Eastern population spans from the coastline of Sudan down through Ethiopia and Kenya to Central Tanzania. A separate population exists in Southern Africa, from Angola and Zimbabwe to the Cape of Good Hope at the southern tip of the continent. Although the Eastern African aardwolves tend to be larger than the southern inhabitants, biologists believe the two populations remain the same species, despite the geographic separation.
Due to their specialized diet, aardwolves prefer arid shrubland and grassy terrains where large insect colonies thrive. They do not require trees for shade because of their nocturnal nature and spend their days in underground dens. Aardwolves avoid mountain forests, as their primary prey feeds upon grass located in open savannahs. This occasionally brings them near human agriculture, which has caused conflicts in the past.
Although aardwolves can reproduce at any time of the year, most tend to breed once a year before the onset of the rainy season, when their food source is most active. For most areas, this is late June or early July, however, some breeding pairs prefer autumn. Aardwolves are polygynous, however, and will pair bond and raise cubs together with one mate each year. Both sexes will announce their breeding intention by secreting a pungent paste from their anal gland to mark territory. Males will defend territories and seek out females near their area or within the territories of weaker males. Females often choose to mate with the most dominant male in the vicinity, which sometimes creates conflicts between males.
After a 90-day gestation, two to five cubs are born within a den where they rely upon both parents for food and protection. For the first three months, the father protects the den from intruders or predators, while the mother cares for their young. At night, as the female leaves the den to forage, the male remains with the cubs at the den. Around three months of age, the cubs leave the den and begin searching for food on their own. By six months, most cubs are independent but may remain with their mother until the next year’s breeding season.
Young aardwolves reach maturity around two years old, after which they can have litters of their own. Due to their secretive nature, debate remains on the lifespan of aardwolves in the wild. However, we know other hyena species can live up to 15 years old in the wild, and the longest-lived aardwolf in captivity survived for 20 years.
Generally, mesocarnivores maintain a wide variety of food sources in their diet, however, a few are specialists when foraging. Aardwolves concentrate almost entirely on termites for sustenance. Not only do they solely eat termites but focus most effort on only one genus of termite, the Trinervitermes, who live in dense, yet sparse colonies in the grasslands of East and South Africa. Although different species of these termites reside in each locale, the tactic of raiding termite mounds remains the same. Aardwolves have long, rough tongues that sweep up termites quickly and efficiently. Furthermore, their tongues have adapted to resist the defensive noxious pheromones and stinging bites of the soldier termites.
Even if living together, aardwolves hunt alone and often must travel up to five miles each night in search of enough mounds. When the Trinervitermes termites become dormant in the winter, the finicky eaters then switch to a backup food source of other termite species. They are also known to eat invertebrates, eggs, and seldomly small mammals or birds, but this is likely when termites become unavailable. Contrary to the reputation of their fearsome cousins, aardwolves do not scavenge from carcasses. However, they are occasionally seen around carrion, but field studies prove they are eating the beetles and other insects attracted to the decomposing meat.
Adult aardwolves have few predators, but leopards, lions, and other hyenas are all known to prey upon them if the opportunity arises. Dens with cubs can sometimes be sought out by black-backed jackals, but aardwolf fathers are known to repel these attempts when possible. Unfortunately, humans account for much of aardwolf mortality through both direct and indirect methods.
To avoid the blazing daytime sun and match the activity patterns of termites, aardwolves are almost exclusively nocturnal. Daytime is spent sleeping in an excavated, underground den. Once a termite mound is located, they systematically intercept lines of termites leaving the mound in search of grass to feed upon. Unlike the armadillo, they do not destroy the mound itself, instead only consume termites outside of the mound’s protection. This method allows colonies to replenish their numbers and be a renewal food source well into the future. Aardwolves never need to seek out a water source, they receive all the moisture they require from the succulent tissue of termites.
Aardwolves communicate with one another through olfactory and auditory cues. They produce an odoriferous secretion, known as paste, from their anal gland that is unique to individuals and wiped upon landmarks. This paste is used to mark territory boundaries and convey signals to mates. Aardwolves can even use this noxious paste as a defensive mechanism against predators. Although usually silent, some clucking and roaring vocalizations have been observed when in danger or during a conflict with a rival neighbor.
INTERACTIONS WITH HUMANS
Aardwolves are very shy and keep their distance from humans. Still, throughout history, they have been persecuted due to misconceptions. Local ranchers once believed they attacked livestock, so all aardwolves were either shot on sight or poisoned. Conservationists were able to educate ranchers on the exclusive termite prey of aardwolves, and now the harmless hyena is welcomed by most livestock producers to control the pasture-damaging termites. Unfortunately, mistaken identity with their predatory cousins still leads to unintentional killings.
Being struck by cars is another leading cause of death among aardwolves, and domestic dogs often attack those who venture close to civilization. Some still actively hunt aardwolves for sport or food. Yet, the largest threat to their overall population is habitat destruction. As humans encroach on their habitat, termite mounds are destroyed eliminating their critical food source. Although IUNC lists aardwolves as a species of Least Concern, real threats remain to local populations of this unique mesocarnivore.
Like other mesocarnivores, aardwolves have long been misunderstood. Although related to one of the continent’s fiercest carnivores, these docile and secretive insectivores only pose beneficial attributes to humans. By controlling the primary pest to local agriculture, aardwolves promote grass and crop health, while posing no danger to livestock. Still, humans and our dogs account for most aardwolf deaths. More research on their population numbers and critical habitat is needed to ensure their stability. Then, further education must take place to teach those living near aardwolves about their harmless nature and beneficial attributes to our society. Hopefully, we can accomplish these important tasks before aardwolf populations suffer due to being misunderstood.
For further reading:
University of Michigan, Animal Diversity Web: Proteles cristata
Fact Animal: Aardwolf Facts
Africa Geographic: Aardwolf