Common Warthog (Phacochoerus africanus): Facts and Diet

Common and desert warthogs

There are two warthog species. The common warthog lives across much of sub-Saharan Africa, while the much rarer desert warthog (Phacochoerus aethiopicus) is found only in dry country in the Horn of Africa, in northern Kenya, Somalia and eastern Ethiopia. For many years they were treated as one species, and older books use the name P. aethiopicus for both.

The desert warthog differs in its skull and teeth: adults typically lack the incisor teeth that common warthogs keep, and it has differently shaped warts and ears. The common warthog is divided into several subspecies, such as the Nolan warthog of West Africa, the eastern warthog of East Africa and the southern warthog of southern Africa.

Appearance

A warthog looks like a lean, long-legged gray pig with a big head. Its skin is gray to blackish, with only sparse bristles, but a mane of long, coarse hair runs from the head down the middle of the back. The mane can be raised when the animal is excited. The tail is thin and ends in a tuft of hair. Warthogs often take on the color of the soil they last wallowed in, so they may look red, brown or gray.

The face carries thick bumps of skin often called warts. Males have large ones below the eyes and smaller ones between the eyes and tusks, plus pale whiskers along the jaw; females have smaller warts. These are not true warts caused by a virus but pads of thickened skin and connective tissue. See Why do warthogs have warts? for what they are for.

The tusks are elongated canine teeth that grow throughout life. The upper pair curves up and out and can exceed 25 cm (10 in) in big males. The lower pair is shorter but kept razor sharp because it rubs against the upper tusks.

Size

Males are noticeably larger and heavier than females, with bigger tusks and warts. A warthog is much lighter than a farm pig of the same length because of its long legs and lean body. Warthogs have almost no fat under the skin, which makes them sensitive to heat and cold.

Habitat and range

Common warthogs live across sub-Saharan Africa, from Senegal and Mauritania in the west, through the Sahel and East Africa, and south to Namibia, Botswana and eastern South Africa.

They prefer open and lightly wooded savanna, grassland, floodplains and semi-arid bush, from sea level up to about 3,000 m (9,800 ft) on mountains such as Kilimanjaro. They avoid dense rainforest and true desert. Good warthog habitat needs short grass for grazing, water or mud for wallows, and burrows for shelter.

Diet: grazing on their knees

The warthog is an omnivore, but most of its diet is plants, especially short grasses. In the wet season it grazes fresh grass shoots and seeds. In the dry season, when grass withers, it digs for underground rhizomes, bulbs and roots with its tough snout, and these juicy parts also provide water.

To feed, a warthog often bends its front legs and shuffles along on its wrists. Hard calluses protect these joints. It also eats fruit, bark, fungi, insects, bird eggs and the occasional carcass, and it is known to eat dung. Read more in What do warthogs eat?.

Behavior and burrows

Warthogs are active by day and spend the night underground. They rarely dig their own homes. Instead they use and enlarge burrows dug by the aardvark or other animals. A warthog usually reverses into its burrow so that it faces outward with tusks forward, ready to defend itself or dash out.

Females live with their young in family groups called sounders, usually of a few to about 18 animals. Young males form bachelor groups, and adult males mostly live alone, joining sounders only to mate. Warthogs are not territorial; the home ranges of different groups overlap and they share wallows and waterholes.

To keep cool, warthogs wallow in mud, which also helps protect the skin from biting insects and sun. They often let oxpeckers, banded mongooses and even vervet monkeys pick ticks from their bodies. On cold nights, a whole sounder may huddle together in a burrow.

When alarmed, warthogs run at up to about 48 km/h (30 mph) with their tails held straight up, a sight familiar to safari visitors.

Home ranges are fairly small for an animal of this size, usually between about 0.6 and 3.3 square kilometers (0.2–1.3 sq mi), though groups may shift their range when water runs short in the dry season. Densities vary widely, from about one to ten warthogs per square kilometer in many protected areas to much higher numbers on short-grass lawns near lakes.

Senses and communication

Warthogs have fairly poor eyesight but keen hearing and an excellent sense of smell, which they use to find buried bulbs and to detect predators. They also pay attention to the alarm calls of birds, monkeys and antelopes sharing the savanna.

They communicate with a range of sounds. Grunts keep a sounder in contact while feeding, squeals and shrieks signal fear or pain, and males grunt, growl and grind their teeth during fights and courtship. A loser in a fight usually squeals and runs off, and the winner rarely follows.

Smell is just as important. Warthogs have scent glands near the eyes and the tusks, which they rub on trees, posts and the ground to mark sleeping areas, feeding spots and waterholes. Friendly animals rub these glands against each other, and females in breeding condition advertise it with scent from urine.

Myths and facts

Myth: warthogs forget danger within seconds. A popular online claim says warthogs have such poor memory that they stop running and go back to feeding as soon as a predator is out of sight. There is no scientific evidence for this. Warthogs often do return to feeding quickly, but that is normal for prey animals that cannot afford to stop eating every time a predator appears.

Myth: warthogs dig with their tusks. Warthogs dig mainly with their broad, tough snouts and their front feet. The tusks are used for fighting and defense.

Myth: the warts are a disease. The facial warts are normal body parts made of thick skin and tissue, not infected growths. They are larger in males and act as padding in fights.

Fact: warthogs are related to farm pigs. Warthogs belong to the pig family, Suidae, together with the wild boar, the ancestor of the domestic pig, and African relatives such as the bushpig and giant forest hog.

Reproduction and life cycle

Warthogs breed seasonally, timed with the rains. Males compete for females in estrus, fighting by pushing and clashing their heads together, and the facial warts and blunt upper tusks take most of the blows.

Pregnancy lasts about five and a half months (170–175 days), one of the longest among pigs. Before giving birth, a female leaves her group and has her litter in a burrow. Litters usually contain two to four piglets, but range from one to about eight. The young stay underground for several weeks, start grazing at a few weeks old and are weaned at around five to six months. Females in a sounder sometimes nurse each other’s young.

Warthogs reach maturity at about 18–20 months, though males usually do not get a chance to mate until they are around four years old.

Predators, lifespan and conservation status

Lions and leopards are the main predators of adult warthogs, along with spotted hyenas, African wild dogs, cheetahs and crocodiles. Jackals, martial eagles and large owls may take piglets, and fewer than half of piglets survive their first year. Adults defend themselves with their tusks, and a mother will charge to protect her young; warthogs have been known to wound attacking lions.

In the wild, warthogs typically live 7–11 years, and some reach 15–18 years. In zoos they can live around 20 years.

The IUCN lists the common warthog as Least Concern, because it has a very wide range and remains common in many protected areas. Local populations can be hit hard by droughts, disease and heavy hunting, and the species has disappeared from parts of its former range. The desert warthog, by contrast, is poorly known.

Warthogs and people

Warthogs are among the most familiar animals on African safaris, often seen grazing near camps and roads. They are also hunted for meat and sometimes come into conflict with farmers when they dig up crops. Warthog ivory from the tusks is carved into small objects for the tourist trade in parts of eastern and southern Africa. The best-known warthog in popular culture is Pumbaa from the film The Lion King.

Outside Africa, warthogs are mostly seen in zoos. Since around 2020, a small free-ranging population descended from animals that escaped from game ranches has been reported in southern Texas, where wildlife managers watch it as a possible invasive species. For an animal that can dig, breed fairly quickly and live in dry country, an introduced population could compete with native wildlife and damage farmland.