Aardwolf

For other uses, see Aardwolf (disambiguation).

Aardwolf Temporal range: Pleistocene - Recent
Aardwolf
Conservation status
Least Concern (IUCN 3.1)
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Carnivora
Family:	Hyaenidae
Subfamily:	Protelinae Flower, 1869
Genus:	Proteles I. Geoffroy Saint-Hilaire, 1824
Species:	P. cristata
Binomial name
Proteles cristata Sparrman, 1783
Aardwolf range

The aardwolf (Proteles cristata) is a small, insectivorous mammal, native to East Africa and Southern Africa. Its name means "earth wolf" in the Afrikaans / Dutch language. It is also called "maanhaar jackal", or civet hyena, based on the secretions (civet) from their anal glands. The aardwolf is in the same family as the hyenas. Unlike its relatives in the order Carnivora, the aardwolf does not hunt large animals, or even eat meat on a regular basis; instead it eats insects, mainly termites - one aardwolf can eat about 200,000 termites during a single night by using its long, sticky tongue to capture them. The aardwolf lives in the scrublands of eastern and southern Africa - these are open lands covered with stunted trees and shrubs. The aardwolf is nocturnal, resting in burrows during the day and emerging at night to seek food. Their diet consists mainly of termites, insect larvae, and the carrion of larger animals.

Taxonomy

The aardwolf is the only surviving species in the mammalian subfamily Protelinae. There is disagreement as to whether there are any subspecies or if the species is monotypic. Some sources say that there are two subspecies: Proteles cristatus cristatus of Southern Africa and Proteles cristatus septentrionalis of East Africa. Whereas others say it is monotypic.

The aardwolf is usually classified with the Hyaenidae, though it was formerly placed into the family Protelidae.

Etymology

The genus 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 5 toes on their front feet and four on the rear. The species name, cristatus comes from Latin and means "provided with a comb", relating to their mane.

Physical characteristics

Detail of head - taken at the Cincinnati Zoo. Note the ability to rotate the ears.

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. The mane is raised during confrontations in order to make the aardwolves appear larger. It is missing the throat spot that others in the family have. The aardwolf is about 55 to 80 centimetres (22 to 31 in) long, excluding its bushy tail, which is about 20–30 centimetres (7.9–11.8 in) long, and stands about 40 to 50 centimetres (16 to 20 in) tall at the shoulders. An adult aardwolf weighs approximately 7–10 kilograms (15–22 lb), sometimes reaching 15 kilograms (33 lb). The front feet have five toes each, unlike the four-toed hyena. The teeth and skull are similar to those of the hyena, though smaller, and its cheek teeth are specialised for eating insects. Its ears are very similar to the Striped Hyena.

As the aardwolf ages, it will normally lose some of its teeth, though this has little impact on their feeding habits due to the softness of the insects that they eat. The aardwolf has two anal glands that secrete a musky fluid for marking territory and for communicating with other aardwolves.

Aardwolf skull

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 savannahs, 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, will occupy a territory of 1–2 square kilometres (0.39–0.77 sq mi).

Behavior

Aardwolf at the San Antonio Zoo

Aardwolves are shy and nocturnal, sleeping in underground burrows by day. They usually use existing burrows of aardvarks, porcupines or springhares, despite being capable of creating their own.

They have often been mistaken for solitary animals. In fact, they live as monogamous pairs with their young. If their territory is infringed upon, they will chase the intruder up to 400 metres (1,300 ft). If the intruder is caught a fight will occur, which is accompanied by hoarse barking and a type of roar. The majority of incursions occur during mating season, when they can occur 1-2 times 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 5 millimetres (0.20 in) long streaks. 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 50 metres (160 ft). At this rate, an individual may mark 60 marks per hour.

An aardwolf pair may have up to ten dens, and numerous middens, within their territory. When they deposit feces at their middens, they dig a small hole and then cover it with sand. Their dens may be abandoned aardvark or porcupine 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 6 months. During the summer, they may rest outside their den during the night, and sleep underground during the heat of the day.

Aardwolfs are not fast runners nor are they particularly adept at fighting off predators. Therefore, when threatened, the aardwolf will attempt to mislead its foe by doubling back on its tracks. If confronted it will raise its mane in an attempt to appear more menacing. It will also emit a foul-smelling liquid from its anal glands.

Feeding

The aardwolf feeds primarily on termites and more specifically on Trinervitermes trinervoides. They locate their food by sound and also from the scent secreted by the soldier termites. An aardwolf may consume up to 200,000 termitesper night using its sticky, long 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 will often memorize the location of such nests and return to them. During certain seasonal events, such as the onset of the rainy season and the cold of mid-winter, the primary termites become scarce and so the need for other forms of sustenance becomes pronounced. During these times the aardwolf will seek out Hodotermes mossambicus, a type of harvester termite. They are also known to feed on other insects, larvae, eggs and occasionally small mammals and birds, but these constitute a very small percentage of their total diet. Unlike other hyenas, aardwolves do not scavenge or kill larger animals.The adult aardwolf was formerly assumed to forage in small groups, however 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 25–100 centimetres (9.8–39.4 in).

Breeding

The breeding season varies depending on their location, but normally takes place during autumn or spring. During the breeding season, unpaired male aardwolves will search their own territory, as well as others, for a female to mate with. Dominant males will also mate opportunistically with the females of less dominant neighboring aardwolves. This can often result in conflict between rival males. Gestation lasts between 89 and 92 days, producing two to five cubs (most often two or three) during the rainy season (Nov-Dec), when termites are more active. They are born with their eyes open but initially are helpless, and weigh around 200–350 grams (7.1–12.3 oz). 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 will often share a den with their mother until the next breeding season. By the time the next set of cubs is ready to start foraging, the older cubs have moved on. They can achieve a lifespan of up to 24 years when in captivity. Aardwolves generally achieve sexual maturity at one and a half to two years of age.

Conservation

The aardwolf has not seen decreasing numbers and they are 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 the food is good. Because of these factors, the IUCN has rated the aardwolf as least concern. They are persecuted by man because of the mistaken belief that they prey on livestock. However, they are actually beneficial to the farmers because their food, the termites are detrimental to farming and they eat 200,000 per night.

Interaction with humans

Agriculture may create a negative impact on their population due to use of poisons by farmers. They are often considered useful, non-dangerous animals by farmers. However, in some areas the aardwolf is hunted for its fur. Encounters with dogs are another threat.

Illustration of Proteles cristatus

References

• Anderson, M.; Mills, G. (2008). Proteles cristatus: Aardwolf. In: IUCN 2008. IUCN Red List of Threatened Species. Retrieved 22 March 2009.

• Goodwin, George G. (1997). "Aardwolf". In Johnston, Bernard. Collier's Encyclopedia. I: A to Ameland (1st ed.). New York, NY: P.F. Collier. p. 3. 

• Hoiberg, Dale H., ed. (2010). "aardwolf". Encyclopedia Britannica. I: A-Ak - Bayes (15th ed.). Chicago, IL: Encyclopedia Britannica, Inc. p. 4. ISBN 978-1-59339-837-8. 

• International Masters Publishers (1998). Wildlife Fact File. Group 1. IMP Publishing Ltd. Card 144. ISBN 978-1886614772. 

• Koepfli, Klaus-Peter; Jenks, Susan M.; Eizirik, Eduardo; Zahirpour, Tannaz; Van Valkenburgh, Blaire; Wayne, Robert K. (2006). "Molecular systematics of the Hyaenidae: Relationships of a Relictual Lineage Resolved by a Molecular Supermatrix" (PDF). Molecular Phylogenetics and Evolution 38 (3): 603–620. doi:10.1016/j.ympev.2005.10.017. ISSN 1055-7903. 

• Koehler, C. E.; Richardson, P. R. K. (1990). "Proteles cristatus". Mammalian Species (American Society of Mammalogists) 363: 1–6. JSTOR 3504197. 

• Oxford English Dictionary Online (2013). "maanhaar". Oxford English Dictionary. Retrieved 2013-11-18. 

• Richardson, Phillip K. R.; Bearder, Simon K. (1984). "The Hyena Family". In MacDonald, David. The Encyclopedia of Mammals. New York, NY: Facts on File Publication. pp. 158–159. ISBN 0-87196-871-1. 

• Rieger, Ingo (1990). "Hyenas". In Parker, Sybil P. Grzimek's Encyclopedia of Mammals 3. New York, NY: McGraw-Hill Publishing Company. pp. 570–571. ISBN 0-07-909508-9. 

• Wozencraft, W. Christopher (2005). "Order Carnivora". In Wilson, Don E.; Reeder, DeeAnn M. Mammal Species of the World: A Taxonomic and Geographic Reference. 1 (3rd ed.). Baltimore, MD: Johns Hopkins University Press. p. 573. ISBN 0-8018-8221-4. 

Additional Reading

• Skinner, J. D.; Chimimba, Christian T. (2006). The Mammals of the Southern African Sub-region (3rd ed.). Cambridge University Press. ISBN 978-0-521-84418-5. Retrieved 15 March 2013. 

External links

• Animal Diversity Web
• IUCN Hyaenidae Specialist Group Aardwolf pages on hyaenidae.org
• Texts on Wikisource:
  • "Aard-wolf". Encyclopædia Britannica (11th ed.). 1911 
  • "Aard-wolf". Collier's New Encyclopedia. 1921.