AARDVARK: Tubulidentata

PHYSICAL CHARACTERISTICS

Aardvarks have elongated, or stretched-out, heads with a pig-like snout and tubular ears. Their muscular, arched bodies are protected by a thick, grayish brown skin that is covered with bristles. The front feet have four toes as well as sharp claws, while the back feet have five toes. The cone-shaped tail is short and tapered, smaller at the end. The long tongue is sticky to help catch insects. Adult aardvarks are 67 to 79 inches (170 to 200 centimeters) long and weigh anywhere from 88 to 143 pounds (40 to 65 kilograms).

The word aardvark means "earth pig" in Dutch. In addition to having a pig-like snout, this mammal resembles a pig in the way it uses its front feet to dig. Like the tail, the snout tapers at the end, and it has two nostrils that can be closed. Although the legs are short, they are powerful—strong enough to break through rock-solid termite mounds. The back legs are slightly longer than the front legs. Despite having soles on the hind feet, aardvarks move on their toes and use the front feet, with their long claws, for digging.

Adults have about twenty teeth, and they are located in the back of the mouth. These column-shaped teeth grow throughout the aardvark's lifetime and, unlike human teeth, do not have protective enamel coating. Instead, each tooth is made of dentin, a material that is harder than bone.

GEOGRAPHIC RANGE

Though not common anywhere, aardvarks live primarily in the grassland and woodlands of the part of Africa south of the Sahara desert. They have also been seen in rainforests.

HABITAT

The deciding factor for where aardvarks live is availability of food. They also require sandy soil, as opposed to rocks, so that they can dig for termites. Aardvarks live in underground burrows that are 6.5 to 9.8 feet (2 to 3 meters) long, at 45 degree angles. At the end of the tunnel is a rounded "room" where the aardvark curls up to sleep. Female aardvarks give birth in this chamber. Although burrows usually have just one entrance, some have numerous entryways as well as several tunnels extending from the main passage.

DIET

Aardvarks began eating termites thirty-five million years ago, and that's still their preferred meal. A hill of termites is not enough to satisfy an aardvark, however, so it searches for entire termite colonies. These colonies march in columns 33 to 130 feet (10 to 40 meters) long, which makes it easy for the aardvark to suck the termites through its nostrils. When attacking a termite mound, the aardvark starts digging at the base with his front claws. Once the termites begin escaping, it extends its tongue and traps them with its sticky saliva. Aardvarks also eat ants and locusts, a type of grasshopper.

In addition to these insects, aardvarks eat an underground fruit of the cucumber species, probably as a source of water. Cucumis humifructus is known in South Africa as the "aardvark pumpkin" or "aardvark cucumber." One tribe of native people, the !Kung San, call this plant "aardvark dung" because the aardvark buries its feces outside abandoned aardvark burrows and the plant grows from seeds left in the aardvark's feces.

BEHAVIOR AND REPRODUCTION

Aardvarks are solitary creatures, they prefer to live alone and have never been found in large numbers. Because they are nocturnal, nighttime, animals, they are not seen very often. In the warmer seasons, they come out of their burrows just after the sun sets. They are able to hunt and forage, gather food, even if it is a moonless night because they rely on their sense of smell to locate termites. Aardvarks cover 1.2 to 3 miles (2 to 5 kilometers) each night at a rate of 1,640 feet (500 meters) per hour.

When searching for food, aardvarks move about in a zigzag formation with their noses to the ground. It is thought that the fleshy tentacles, hair-like growths, around the nostrils might actually be chemical receptors that help find food.

Aardvarks are known for their digging abilities. In fact, aardvarks can dig a burrow 3.3 feet (1 meter) deep faster than a group of six adults with shovels!

The mating season of the aardvark varies. In some areas, mating occurs between April and May, with offspring born in October or November. In other regions, offspring are born in May or June. Females carry their offspring for seven months before giving birth, and they bear only one offspring with each pregnancy. The baby weighs approximately 4 pounds (2 kilograms). Newborn aardvarks are hairless with pink, tender skin. They remain in the burrow with their mothers for two weeks. After two weeks they follow their mothers in the nightly search for food. The infant aardvark does not eat solid food until around three months, preferring its mother's milk until that time.

Aardvarks move away from the mother's den after six months and build burrows a few feet (meters) away, but they continue to forage together. Male aardvarks leave their mothers completely during the next mating season, but females stay with mothers until the birth of the next baby. Male aardvarks roam while females remain in a consistent home range. Because of this, experts believe aardvarks to be polygamous (puh-LIH-guh-mus), having more than one mating partner.

Humans are not the only hunters of aardvarks. Lions, leopards, and hyenas are the main predators, animals that hunt them for food, of aardvarks. Pythons feed on young aardvarks as well. When they sense danger, aardvarks retreat to the nearest hole. If a hole is not nearby, they use their powerful claws to dig one. The claws push the dirt backwards while the tail sweeps it away. In the event they cannot get to safety, aardvarks will lie on their back and fight with all four feet.

AARDVARKS AND PEOPLE

European colonialists hunted aardvarks for their meat and hide. Africans continue to hunt aardvarks and consider it a sport as well as a means of survival.

CONSERVATION STATUS

Aardvarks are classified as Vulnerable, facing a high risk of extinction in the wild, by the World Conservation Union (IUCN).

FOR MORE INFORMATION

Books:

Joyce, Peter. From Aardvark to Zebra: Secrets of African Wildlife. Cape Town, South Africa: Struik, 2000.

McColaugh, Doreen Wolfson. Wild Lives Guidebook. African Wildlife Federation, 1997. Online at http://www.awf.org/wildlives/60 (accessed on July 9, 2004).

Web sites:

African Wildlife Federation. http://www.awf.org (accessed on July 9, 2004).

"Science & Nature: Animals." BBC.http://www.bbc.co.uk/nature/reallywild/amazing/aardvark.shtml (accessed on July 9, 2004).