An unusual hyena

There is controversy among hyena taxonomists as to the phylogeny of hyenids. The evolution of hyenas occurred in Eurasia about 20 million years ago and spread slowly through Africa until they established themselves in sub-saharan Africa around 11 million years ago. They fall into a sub-order of Carnivora called Feliformia along with cats, civets and genets, and their closest relatives, the mongoose.

Spotted hyena on the short grass plains.

Two hyena species- the brown and striped hyena- are the most closely related and share the genus

Hyaena.

The spotted hyena, who appears in the fossil record around 3.5 million years ago, is the largest of the hyenas and shares a niche similar to lions posing as one of the lion’s biggest competitors. Their strong stomach acid and reinforced skulls allow them to crush and digest even the largest of animal bones. However, silently lurking in the shadows of these large hyenas is a small hyena, so distantly related that some specialists argue it should belong to its own family.

The aardwolf (Proteles cristata), unlike its meat eating relatives, is a very specialized insect eater. Instead of the massive cheek teeth that the other hyenas have, the aardwolf’s are reduced to little pegs. An aardwolf’s sight, hearing, and smell are well developed allowing it to hear termites as they forage. Instead of the strong jaw-closing muscle of the other hyenas, the jaw-opening muscle is well developed allowing rapid opening and closing of the mouth. Extra large salivary glands, a tough tongue, and sticky saliva all help in lapping up termites.

An Aardwolf strains to defecate before heading out to forage.

Surprisingly, aardwolfs are not well adapted to digging as one would expect of a termite eater, but instead specialize on termite species that forage in the open. Using their ears to find their food, they can consume up to 300 000 termites in a day (1.2kg). Since termites, especially the soldiers, contain chemical defenses, aardwolfs have to feed on workers rapidly before the soldiers come out. Due to their feeding method of licking, aardwolves consume a lot of sand. A single defacation can weigh up to 1 kg (approx. 10% of its body weight).

Aardwolves are monogamous and territorial. Their territory size is determined by the abundance of termites- approximately 3 000 termite colonies in each territory with 55 0000 termites in each colony. Though living in a territory as a pair, they are occasionally promiscuous.

(Facts checked and backed from Lars Werdelin, Mammals of Africa, edited by Kingdon & Hoffman, Vol V. 2013)