The aardwolf (''Proteles cristata'') is an
insectivorous
A robber fly eating a hoverfly
An insectivore is a carnivorous animal or plant that eats insects. An alternative term is entomophage, which can also refer to the human practice of eating insects.
The first vertebrate insectivores were ...
species of
hyena
Hyenas, or hyaenas (from Ancient Greek , ), are feliform carnivoran mammals of the family Hyaenidae . With only four extant species (each in its own genus), it is the fifth-smallest family in the Carnivora and one of the smallest in the clas ...
, native to
East and
Southern Africa. Its name means "earth-wolf" in
Afrikaans and
Dutch.
[ It is also called maanhaar-jackal] (Afrikaans for " mane-jackal"), termite-eating hyena and civet hyena, based on its habit of secreting substances from its anal gland, a characteristic shared with the African civet.[
Unlike many of its relatives in the order ]Carnivora
Carnivora is a Clade, monophyletic order of Placentalia, placental mammals consisting of the most recent common ancestor of all felidae, cat-like and canidae, dog-like animals, and all descendants of that ancestor. Members of this group are f ...
, the aardwolf does not hunt large animals. It eats insects and their larvae, mainly termites; one aardwolf can lap up as many as 250,000 termites during a single night using its long, sticky tongue. The aardwolf's tongue has adapted to be tough enough to withstand the strong bite of termites.[
The aardwolf lives in the ]shrubland
Shrubland, scrubland, scrub, brush, or bush is a plant community characterized by vegetation dominated by shrubs, often also including grasses, herbs, and geophytes. Shrubland may either occur naturally or be the result of human activity. It m ...
s of eastern and southern Africa – open lands covered with stunted trees and shrubs. It is nocturnal
Nocturnality is an animal behavior characterized by being active during the night and sleeping during the day. The common adjective is "nocturnal", versus diurnal meaning the opposite.
Nocturnal creatures generally have highly developed sens ...
, resting in burrow
An Eastern chipmunk at the entrance of its burrow
A burrow is a hole or tunnel excavated into the ground by an animal to construct a space suitable for habitation or temporary refuge, or as a byproduct of locomotion. Burrows provide a form of sh ...
s during the day and emerging at night to seek food.
Taxonomy
The aardwolf is generally classified with the hyena family Hyaenidae, though it was formerly placed in its own family Protelidae. Early on, scientists felt that it was merely mimicking the striped hyena, which subsequently led to the creation of Protelidae. Recent studies have suggested that the aardwolf probably diverged from other hyaenids early on; how early is still unclear, as the fossil record and genetic studies disagree by 10 million years.
The aardwolf is the only surviving species in the subfamily
In biological classification, a subfamily (Latin: ', plural ') is an auxiliary (intermediate) taxonomic rank, next below family but more inclusive than genus. Standard nomenclature rules end subfamily botanical names with "-oideae", and zoologi ...
Protelinae. There is disagreement as to whether the species is monotypic, or can be divided into subspecies
In biological classification, subspecies is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (morphology), but that can successfully interbreed. Not all species ...
''P. c. cristatus'' of Southern Africa and ''P. c. septentrionalis'' of East Africa
East Africa, Eastern Africa, or East of Africa, is the eastern subregion of the African continent. In the United Nations Statistics Division scheme of geographic regions, 10-11-(16*) territories make up Eastern Africa:
Due to the historical ...
.[
A 2006 molecular analysis indicates that it is phylogenetically the most basal of the four extant hyaenidae species.
]
Etymology
The generic name ''proteles'' comes from two words both of Greek origin, ''protos'' and ''teleos'' which combined means "complete in front" based on the fact that they have five toes on their front feet and four on the rear.[ The specific name, ''cristatus'', comes from Latin and means "provided with a comb", relating to their mane.][
]
Description
The aardwolf resembles a very thin striped hyena, but with a more slender muzzle, black vertical stripes on a coat of yellowish fur, and a long, distinct mane down the midline of the neck and back. It also has one or two diagonal stripes down the fore- and hind-quarters, along with several stripes on its legs. The mane is raised during confrontations to make the aardwolf appear larger. It is missing the throat spot that others in the family have.[ Its lower leg (from the knee down) is all black, and its tail is bushy with a black tip.][
The aardwolf is about long, excluding its bushy tail, which is about long,][ and stands about tall at the shoulders.] An adult aardwolf weighs approximately , sometimes reaching . The aardwolves in the south of the continent tend to be smaller (about ) than the eastern version (around ). This makes the aardwolf, the smallest extant member of the Hyaenidae family.[ The front feet have five toes each, unlike the four-toed hyena.][ The teeth and skull are similar to those of other hyenas, though smaller,][ and its cheek teeth are specialised for eating insects.][ It does still have canines, but, unlike other hyenas, these teeth are used primarily for fighting and defense.][ Its ears, which are large,][ are very similar to those of the striped hyena.][
As an aardwolf ages, it will normally lose some of its teeth, though this has little impact on its feeding habits due to the softness of the insects that it eats.]
Distribution and habitat
Aardwolves live in open, dry plains and bushland, avoiding mountainous areas.[ Due to their specific food requirements, they are only found in regions where termites of the family Hodotermitidae occur. Termites of this family depend on dead and withered grass and are most populous in heavily grazed grasslands and ]savannah
A savanna or savannah is a mixed woodland-grassland (i.e. grassy woodland) ecosystem characterised by the trees being sufficiently widely spaced so that the Canopy (forest), canopy does not close. The open canopy allows sufficient light to rea ...
s, including farmland. For most of the year, aardwolves spend time in shared territories consisting of up to a dozen dens, which are occupied for six weeks at a time.
There are two distinct populations: one in Southern Africa, and another in East and Northeast Africa. The species does not occur in the intermediary miombo forests.
An adult pair, along with their most-recent offspring, occupies a territory of .
Behavior and ecology
Aardwolves are shy and nocturnal
Nocturnality is an animal behavior characterized by being active during the night and sleeping during the day. The common adjective is "nocturnal", versus diurnal meaning the opposite.
Nocturnal creatures generally have highly developed sens ...
, sleeping in burrows by day.[ They will, on occasion during the winter, become diurnal feeders. This happens during the coldest periods as they then stay in at night to conserve heat.]
They have often been mistaken for solitary animals. In fact, they live as monogamous pairs with their young.[Richardson, P. R. K.]
Aardwolf mating system: overt cuckoldry in an apparently monogamous mammal
" South African Journal of Science 83.7 (1987): 405. If their territory is infringed upon, they will chase the intruder up to or to the border.[ If the intruder is caught, which rarely happens,][ a fight will occur, which is accompanied by soft clucking,][ hoarse barking, and a type of roar.][ The majority of incursions occur during mating season, when they can occur once or twice per week.][ When food is scarce, the stringent territorial system may be abandoned and as many as three pairs may occupy a single territory.][
The territory is marked by both sexes, as they both have developed anal glands from which they extrude a black substance that is smeared on rocks or grass stalks in -long streaks.][ Aardwolves also have scent glands on the forefoot and penile pad. They often mark near termite mounds within their territory every 20 minutes or so. If they are patrolling their territorial boundaries, the marking frequency increases drastically, to once every . At this rate, an individual may mark 60 marks per hour,][ and upwards of 200 per night.][
An aardwolf pair may have up to 10 dens, and numerous feces ]midden
A midden (also kitchen midden or shell heap) is an old dump for domestic waste which may consist of animal bone, human excrement, botanical material, mollusc shells, potsherds, lithics (especially debitage), and other artifacts and ecofact ...
s, within their territory. When they deposit excreta at their middens, they dig a small hole and cover it with sand. Their dens are usually abandoned aardvark, springhare, or porcupine
Porcupines are large rodents with coats of sharp spines, or quills, that protect them against predation. The term covers two families of animals: the Old World porcupines of family Hystricidae, and the New World porcupines of family, Erethizont ...
dens, or on occasion they are crevices in rocks. They will also dig their own dens, or enlarge dens started by springhares.[ They typically will only use one or two dens at a time, rotating through all of their dens every six months. During the summer, they may rest outside their den during the night and sleep underground during the heat of the day.
Aardwolves are not fast runners nor are they particularly adept at fighting off predators. Therefore, when threatened, the aardwolf may attempt to mislead its foe by doubling back on its tracks. If confronted, it may raise its mane in an attempt to appear more menacing. It also emits a foul-smelling liquid from its anal glands.][
]
Feeding
The aardwolf feeds primarily on termites and more specifically on '' Trinervitermes''. This genus of termites has different species throughout the aardwolf's range. In East Africa, they eat ''Trinervitermes bettonianus
''Trinervitermes'' is a termite genus belonging to family Termitidae. Members are native to the Old World. They inhabit grasslands and store grass in their nests or mounds, just below the ground surface. Their grass-collecting activities are main ...
'', in central Africa, they eat ''Trinervitermes rhodesiensis
''Trinervitermes'' is a termite genus belonging to family Termitidae. Members are native to the Old World. They inhabit grasslands and store grass in their nests or mounds, just below the ground surface. Their grass-collecting activities are ma ...
'', and in southern Africa, they eat '' T. trinervoides''. Their technique consists of licking them off the ground as opposed to the aardvark, which digs into the mound.[ They locate their food by sound and also from the scent secreted by the soldier termites.][ An aardwolf may consume up to 250,000 termites per night using its long, sticky tongue.]
They do not destroy the termite mound or consume the entire colony, thus ensuring that the termites can rebuild and provide a continuous supply of food. They often memorize the location of such nests and return to them every few months.[ During certain seasonal events, such as the onset of the rainy season and the cold of midwinter, the primary termites become scarce, so the need for other foods becomes pronounced. During these times, the southern aardwolf will seek out '']Hodotermes
''Hodotermes'' (from Greek ὁδός (hodós), travelling; Latin '' termes'', woodworm) is a genus of African harvester termites in the Hodotermitidae. They range from Palaearctic North Africa, through the East African savannas to the karroid ...
mossambicus'', a type of harvester termite[ active in the afternoon, which explains some of their diurnal behavior in the winter.][ The eastern aardwolf, during the rainy season, subsists on termites from the genera '']Odontotermes
''Odontotermes'', commonly known as the fungus-growing termites, is a termite genus belonging to family Termitidae, which is native to the Old World. They are most destructive in wooden homes, and are agricultural pests in the tropics and subtrop ...
'' and '' Macrotermes''.[ They are also known to feed on other insects, larvae, eggs, and, some sources say, occasionally small mammals and birds, but these constitute a very small percentage of their total diet.][
Unlike other ]hyena
Hyenas, or hyaenas (from Ancient Greek , ), are feliform carnivoran mammals of the family Hyaenidae . With only four extant species (each in its own genus), it is the fifth-smallest family in the Carnivora and one of the smallest in the clas ...
s, aardwolves do not scavenge or kill larger animals.[ Contrary to popular myths, aardwolves do not eat carrion, and if they are seen eating while hunched over a dead carcass, they are actually eating larvae and beetles.][ Also, contrary to some sources, they do not like meat, unless it is finely ground or cooked for them.][ The adult aardwolf was formerly assumed to forage in small groups,][ but more recent research has shown that they are primarily solitary foragers,][ necessary because of the scarcity of their insect prey. Their primary source, ''Trinervitermes'', forages in small but dense patches of .][ While foraging, the aardwolf can cover about per hour, which translates to per summer night and per winter night.][
]
Breeding
The breeding season
Seasonal breeders are animal species that successfully mate only during certain times of the year. These times of year allow for the optimization of survival of young due to factors such as ambient temperature, food and water availability, and cha ...
varies depending on location, but normally takes place during autumn or spring. In South Africa, breeding occurs in early July.[ During the breeding season, unpaired male aardwolves search their own territory, as well as others, for a female to mate with. Dominant males also mate opportunistically with the females of less dominant neighboring aardwolves,][ which can result in conflict between rival males.][ Dominant males even go a step further and as the breeding season approaches, they make increasingly greater and greater incursions onto weaker males' territories. As the female comes into oestrus, they add pasting to their tricks inside of the other territories, sometimes doing so more in rivals' territories than their own.][ Females will also, when given the opportunity, mate with the dominant male, which increases the chances of the dominant male guarding "his" cubs with her.][ Copulation lasts between 1 and 4.5 hours.][Sliwa, Alexander.]
A functional analysis of scent marking and mating behaviour in the aardwolf.
Proteles cristatus (1996).
Gestation
Gestation is the period of development during the carrying of an embryo, and later fetus, inside viviparous animals (the embryo develops within the parent). It is typical for mammals, but also occurs for some non-mammals. Mammals during pregna ...
lasts between 89 and 92 days,[ producing two to five cubs (most often two or three) during the rainy season (November–December),][ when termites are more active.][ They are born with their eyes open, but initially are helpless,][ and weigh around .][ The first six to eight weeks are spent in the den with their parents.][ The male may spend up to six hours a night watching over the cubs while the mother is out looking for food.][ After three months, they begin supervised foraging, and by four months are normally independent, though they often share a den with their mother until the next breeding season.][ By the time the next set of cubs is born, the older cubs have moved on.][ Aardwolves generally achieve sexual maturity at one and a half to two years of age.][
]
Conservation
The aardwolf has not seen decreasing numbers and is relatively widespread throughout eastern Africa. They are not common throughout their range, as they maintain a density of no more than 1 per square kilometer, if food is abundant. Because of these factors, the IUCN has rated the aardwolf as least concern. In some areas, they are persecuted because of the mistaken belief that they prey on livestock; however, they are actually beneficial to the farmers because they eat termites that are detrimental.[ In other areas, the farmers have recognized this, but they are still killed, on occasion, for their fur. Dogs and insecticides] are also common killers of the aardwolf.[
]
In captivity
Frankfurt Zoo in Germany was home to the oldest recorded aardwolf in captivity at 18 years and 11 months.[
]
Notes
References
References
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Further reading
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External links
Animal Diversity Web
* Cam footage from the Namib desert https://m.youtube.com/watch?v=lRevqS6Pxgg
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{{Taxonbar, from=Q185295
Mammals described in 1783
Carnivorans of Africa
Hyenas
Mammals of Southern Africa
Fauna of East Africa
Myrmecophagous mammals
Taxa named by Anders Sparrman