Encyclopedia of Animal Cognition and Behavior

Living Edition
| Editors: Jennifer Vonk, Todd Shackelford

Aardvark

  • Brandon Ferrell
  • Kristine O. EvansEmail author
Living reference work entry
DOI: https://doi.org/10.1007/978-3-319-47829-6_838-1

Synonyms

Introduction

The aardvark (Orycteropus afer) is a burrowing quadruped nocturnal mammal that can be found across sub-Saharan Africa. People often mistakenly identify aardvarks as anteaters, and while ants are a primary part of their diet, aardvarks are a different taxonomic grouping and the only extant species in the order Tubulidentata. Aardvarks are an extremely reclusive species and are rarely observed in the wild. African folklore states that sighting an aardvark twice in your lifetime will lead to a long and happy existence (Knothig 2005).

The name aardvark originates from “aarde” meaning earth and “vark” meaning pig. The name is derived from the Afrikaans language, a language derived from Dutch. The scientific name Orycteropus afer is derived from Greek and can roughly be translated to “digger foot of Africa.”

Description

Aardvarks have large bodies with elongated heads and very small necks. They are nocturnal animals that live in dug burrows and come out at night to forage for insects. Their snouts end in a flat nose that has small hairs to keep dirt and insects out of their nostrils. They are covered in coarse fur on most of their bodies except their tail and part of their head. They are naturally a yellowish-gray color but often appear brown or red due to their fur retaining soil from their burrowing activity. It is thought that fur in this mammal is not necessarily to help regulate temperature like with most mammals, but rather to help prevent ants and termites from biting their thick skin during their foraging forays. Due to being a nocturnal species, their skin can burn if they are in the sun for an extended period. This can be problematic for aardvarks kept in captivity, and zookeepers will frequently cover aardvarks in sunscreen to prevent sunburn. A difference that has been noted between male and female aardvarks is that females have lighter colored heads and the tip of the female’s tail is white. While the purpose of this is unknown, it is theorized that it is to help an aardvark cub follow their mother.

Aardvarks are able to independently move their large cylinder-shaped ears and close their nostrils on demand when digging to prevent dirt and insects from entering their ears and nostrils. As is the case with most nocturnal vertebrates, aardvarks are color-blind and have poor vision and rely on their keen sense of hearing and smell to navigate their surroundings. An aardvark’s teeth are very different from the teeth of most other animals and are not meant specifically for grinding or tearing (Brewer 2003). Their teeth are a unique cylinder shape that lacks a root or enamel. The tooth is made of multiple smaller cylinders that are fused together to create the individual teeth. Aardvarks use their highly adapted teeth to break the exoskeleton of the insects it licks with its tongue. One theory on the evolution of the unique shape of their teeth is that it is caused by a symbiotic relationship they have developed with the aardvark cucumber. (Cucumis humifructus) (Knothig 2005). The cucumber is a subterranean fruit that gets its namesake from only animal known to dig them up and eat them – the aardvark. The seeds are then released in the feces, which the aardvark bury. Their large spoon-like claws are good for digging into the hard earth and breaking open cement-like termite mounds. An aardvark’s tail acts as a weight to allow them to stand on their hind legs and grip an insect mound with their forelimbs. This standing position helps provide the grip necessary to break open hard termite mounds with their claws. Once an aardvark is fully grown, they are about 6 ft long (1.83 m) from snout to tail and can weigh between 80 and 150 pounds (36.29 kg and 68.04 kg, respectively) on average.

Habitat

In the wild an aardvark’s habitat consists mostly of open woodland, scrub, and grassland. They generally avoid dense forests, deserts, and mountainous terrain due to being ill-equipped to live in those areas. They prefer to burrow in areas where the soil is loose and easy to dig into and that is within a reasonable distance from their foraging area (Knothig 2005). Aardvarks can largely be found roaming throughout sub-Saharan Africa but are unevenly distributed due to ill-suited terrain and human interference. It is unclear if aardvarks are truly territorial due to lack of empirical studies and their solitary, nocturnal behavior. Some evidence shows aardvark will maintain multiple burrows over a large home range, sometimes even miles apart, each of which will have a specific purpose (Knothig 2005). Some dens may be used as a temporary resting place after a night of foraging forays, and others may exist only to be used for hiding from predators. Aardvarks also construct more permanent dens that are mainly used by females with cubs. However, they generally have several dens in several areas, as well as several tunnels, or tunnels that are made specifically to hide from predators within a home range. Aardvarks are primarily nomadic, with the main exception being for females caring for cubs, which generally stay in one area for safety of her offspring. Their burrows can be quite large – as much as 10–13 m (33–43 ft) long – and generally have several entrances and chambers used for sleeping and rearing offspring. The burrows are built to retain moisture and regulate temperature, making it cool during the day and warm at night. Once aardvarks abandon a burrow to move to a new area, the abandoned burrow can provide an environmental service by trapping seeds of plants in the entrance area where they cannot be destroyed by other factors in the environment. Abandoned burrows also provide an important keystone habitat function for other animal species, some of which are on the International Union for the Conservation of Nature (IUCN) threatened species list (Whittington-Jones et al. 2011). An example of one such group of species would be pangolin (Phataginus spp.) in areas where ranges overlap. Services provided by aardvarks can also extend beyond occupation of abandoned burrows. Some species, such as the aardwolf (Proteles cristata) and the bat-eared fox (Otocyon megalotis), will take advantage of termite mounds opened by an aardvark to eat the stray termites in disturbed mounds.

Diet

An aardvark’s diet mainly consists of ants and termites but can include aardvark cucumber, beetles, and insect larvae. Throughout the year ants are their primary food source, but during the winter months they will switch to prey that is more readily available, such as termites and other insects due to lack of available ants in the environment. An aardvark is willing to walk 10–20 miles per night during foraging forays. They forage in a zigzag pattern until they detect and begin to follow signs of food (Melton 2008). Aardvarks capture their prey using a combination of their long prehensile tongue, their adhesive saliva, and large claws. All of these features together make the aardvark well-suited for accessing ant and termite mounds, some of which can be as hard as concrete. As they eat, their tongues also collect dirt and small rocks which help an aardvark to digest the insects it consumes. Aardvark disturbance at mounds compounds with consecutive night forays. They will start disturbing the mound slowly, inflicting only minor damage; however, after several nights of consecutive visits, they can dig entirely into the ant and termite mounds such that their whole body can fit inside the hole they have created. In captivity an aardvark can be fed a mixture of fruits and vegetables, rice, vitamins, and several other ingredients to replace their natural diet. However, they can be difficult to care for in captivity due to their nocturnal nature as well as their dietary and habitat needs. For the food to be edible, it must be blended into a fluid consistency due to an aardvark’s teeth not adapted for chewing solids.

Vulnerabilities

Even though aardvarks are primarily nocturnal, they are still hunted by animals such as lions (Panthera leo), African leopards (Panthera pardus pardus), hyenas (Hyaenidae), and large snakes (mainly pythons). Warthogs (Phacochoerus africanus) have also been known to attack young aardvarks. Aardvarks are a very cautious and systematic animal. They will complete a specific series of events every time they prepare to leave their burrow. They spend substantial time listening for potential predators prior to departure from their burrow. If they unintentionally make noise that may attract the attention of predators, they will stop and listen again until perceived predation risk is diminished. This hypervigilant behavior continues within a few feet of their burrow such that they may bolt back to the burrow if necessary. Fleeing to a burrow is a primary means of defense in this species. Aardvarks digging unfinished burrows are more vulnerable as they are forced to exit their den backward and do not yet have appropriate escape cover. They also have been shown to use their powerful hind legs and large claws to ward off predators during agonistic interactions. The predominant danger to the aardvark’s habitat and way of life is encroachment by humans. They are regularly killed by farmers for damaging roads, fences, and dams. Aardvarks are hunted for bushmeat and use in traditional medicine. Climate change poses a formidable risk to sustainability of aardvark populations as they may not be able to adapt to minor changes in temperature and are at risk for reduced food availability if prey items are vulnerable to temperature changes.

Life Cycle

Aardvarks have been known to live for about 20 years in captivity, but their life span in the wild is unknown. Aardvarks are solitary in nature and only comingle during mating season where nomadic males will spend several weeks with a female mate before moving on in an attempt to find another female to mate with. Gestation for a female aardvark is about 7 months in duration, and they usually produce a single cub per pregnancy. Newborn cubs are small, pink, hairless, and blind and only weigh about 2 kg. An aardvark cub is almost entirely dependent on its mother during the first 2 weeks post-parturition. During this time the cubs use their hearing and sense of smell in order to navigate their environment. Cubs will remain in the burrow during that 2-week period before being able to venture out on short forays at night with their mother; however, they will not be weaned until approximately 3 months of age. Cubs will begin to create their own burrows just outside of their mother’s burrow at about 6 months of age but will not completely leave their mother’s burrow until around the time they are able to mate. They become capable of reproduction at about 2 years of age.

More facts about aardvarks:
  • Much of the aardvark’s fame is because it is the first animal to appear alphabetically in an English encyclopedia making it largely unknown in countries where English is not the primary language spoken.

  • Aardvarks are commonly called anteaters, but they are not related at all. The reason for the incorrect comparison is due to both being myrmecophagous species, meaning they eat ants and termites primarily.

  • Very little is known about aardvarks due to being reclusive in their natural habitat, and very few are found in captivity.

  • Their powerful legs, feet, and claws are so strong they are able to shift about 2 ft of soil in about 15 s. That is more than a team of men with shovels can do.

  • The aardvark is the only member of the order Tubulidentata, which is a reference to its unique tube-shaped teeth, that is known to still be alive at this point in time.

  • In 1869 the first aardvark to be placed in a zoo was brought to London from South Africa (Goldman 2007).

Cross-References

References

  1. Brewer, D. (2003). Aardvarks. In Mammals (1-59084-467-X) (p. 12). Mason Crest Publishers. Retrieved from http://search.ebscohost.com/login.aspx?direct=true&AuthType=ip,shib&db=f5h&AN=9385417&site=eds-live&custid=magn1307
  2. Goldman, C. A. (2007, December 18). A review of the management of the Aardvark: In captivity. Retrieved from https://zslpublications.onlinelibrary.wiley.com/doi/pdf/10.1111/j.1748-1090.1985.tb02556.x
  3. Knothig, J. (2005). Biology of the aardvark. Retrieved October 2, 2018, from https://www.zuriorphanage.com/wp-content/uploads/2016/01/Biology-of-the-Aardvark-by-Joachim-Knothig.pdf
  4. Melton, D. A. (2008, April 10). The biology of aardvark (Tubulidentata-orycteropodidae). Retrieved from https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1365-2907.1976.tb00204.x
  5. Whittington-Jones, G. M., Bernard, R. T. F., & Parker, D. M. (2011). Aardvark burrows: A potential resource for animals in arid and semi-arid environments. African Zoology, 46(2), 362–370.  https://doi.org/10.3377/004.046.0215.CrossRefGoogle Scholar

Copyright information

© Springer Nature Switzerland AG 2019

Authors and Affiliations

  1. 1.College of Veterinary MedicineMississippi State UniversityMississippi StateUSA
  2. 2.Department of Wildlife, Fisheries and AquacultureMississippi State UniversityMississippi StateUSA

Section editors and affiliations

  • Mystera M. Samuelson
    • 1
  1. 1.The Institute for Marine Mammal StudiesGulfportUSA