Warthogs (Phacochoerus africanus) are found outside forested areas in Africa, from Mauritania to Ethiopia and south to Namibia and eastern South Africa.

Biogeographic Regions: ethiopian (Native )

Common warthogs weigh 50 to 150 kg with females being 15 to 20 percent lighter than males. Head and body length is 900 to 1500 mm. Shoulder height ranges from 635 to 850 mm. Common warthogs have large upper tusks that are 255 to 635 mm long in males and 152 to 255 mm long in females. As their name suggests, warthogs have three pairs of facial warts, comprised of cartilaginous connective tissue. The three types of warts are: 1) the suborbital warts, which may grow as long as 15 cm in males; 2) the preorbital warts, which do not develop as much in females; and 3) the submaxillary warts, which have white bristles.

The head is large with a mane that goes down the spine to the middle of the back. There is sparse hair covering the body. Color is usually black or brown. Tails are long and end with a tuft of hair. Common warthogs do not have subcutaneous fat and the coat is sparse, making them suceptible to extreme environmental temperatures.

Common warthogs can be distinguised from Cape warthogs by the number of incisors. Common warthogs have two upper and four to six lower incisors, in contrast to Cape warthogs, which lack incisors.

Range mass: 50 to 150 kg.

Range length: 900 to 1500 mm.

Sexual Dimorphism: male larger; ornamentation

• Terrestrial

Common warthogs are found in open and wooded savannas, grass-steppes, and semi-deserts in Africa. Common warthogs prefer open areas and avoid rainforest and severe desert. They are found on Kilimanjaro up to an elevation of 3000 m and along coastal regions of Africa. Common warthogs often utlilize formerly wooded areas that have been cleared for pastures.

The distribution of common warthogs is limited by cover, human disturbance, and suitable foraging. Warthogs require areas to cool-off in order to cope with high temperatures. These include wallows. They also require areas in which to stay warm in the evening, such as burrows.

Range elevation: 0 to 3000 m.

Habitat Regions: tropical ; terrestrial

Terrestrial Biomes: savanna or grassland

Other Habitat Features: agricultural

Common warthogs are primarily grazers but also feed on roots, berries, bark of young trees, and occassionaly carrion. They are specialized for grazing short grasses by being able to lower themselves close to the ground on their wrist joints, which are calloused and padded. Common warthogs use their snouts and tusks to excavate rhizomes and bulbs. Rhizomes and bulbs may also provide water for common warthogs during periods of drought. Common warthogs eat their own dung and the dung of rhinoceroses, African buffalos, waterbucks, and francolins.

Animal Foods: carrion

Plant Foods: leaves; roots and tubers; wood, bark, or stems; seeds, grains, and nuts; fruit

Other Foods: dung

Primary Diet: omnivore

Common warthogs have a mutualistic relationship with birds, such as red-billed and yellow-billed oxpeckers. The birds are able to feed on the parasites carried by common warthogs while the warthogs are able to rid themselves of these pests. It is thought that the rooting of the common warthog aids in plant growth by aerating the soil. They are also prey to lions and leopards.

Ecosystem Impact: soil aeration

Species Used as Host:

• N/A

Mutualist Species:

• Red-billed oxpeckers, Yellow-billed oxpeckers

Commensal/Parasitic Species:

• tsetse fly and ticks

The predominant predators of common warthogs are lions. Common warthogs avoid nocturnal predators by being active during the day and sheltering in burrows at night. They also use the warning calls of red-billed and yellow-billed oxpeckers to avoid predators. They are fast runners and usually avoid attack by fleeing. Common warthogs change their activity patterns to avoid humans. In areas with human disturbance, warthogs often become more active nocturnaly.

Known Predators:

• lions (Panthera leo)
• leopards (Panthera pardus)
• cheetah (Acinonyx jubatus)

Common warthogs have poor eyesight, but their senses of hearing and smell are keen. A common warthogs, when alarmed, run with its tail upright as an alarm for conspecifics. During friendly encounters, common warthogs rub their preorbital glands against each other. Female warthogs use frequent urination to demonstrate their readiness for mating to boars. During fights among conspecifics, the loser typically squeaks and flees and the victor usually leaves the losing individual alone. During fights and mating, warthogs grunt and grind their teeth.

Communication Channels: visual ; tactile ; acoustic ; chemical

Perception Channels: visual ; acoustic

Researchers in the eastern Selous Game Reserve, Tanzania found the average lifespan of a warthog was 7 to 11 years. Other literature indicates that warthogs may live as long as 18 years.

Infant warthogs are suceptible to both extreme temperatures and predation, which is why the juvenile survival rate is less than 50% in the first year of life. Other common causes of mortality in adult warthogs are predation, human disturbance, hunting, and disease.

Range lifespan

Status: wild: 15 to 18 years.

Typical lifespan

Status: wild: 7 to 11 years.

Average lifespan

Status: captivity: 20.9 years.

Common warthogs have a polygynandrous mating system. Both males and females have many mates. Males do not defend territories, but when females are in estrus ritualized fighting between males does occur. Fighting involves pushing and striking with the head and blunt upper tusks. The more dangerous lower tusks are rarely used, and injuries or fatalities are rare. Adult males are usually solitary and join female groups briefly for mating. Females attract boars by sight and smell by urinating in a hunched position.

Mating System: polygynandrous (promiscuous)

Mating in common warthogs is seasonally dependent. Females usually become fertile 4 to 5 months after the rainy season has ended and give birth during the dry season. Common warthogs are sexually mature at 18 to 20 months, although males do not typically mate until 4 years of age. Common warthogs are recorded to have the longest gestation of all pigs, ranging from 170 to 175 days. Litters range in size from 1 to 7 piglets, with an average of 3 piglets per litter. Piglets are weaned at about 21 weeks of age.

Female P. africanus spend most of their lives in groups called soundings, but prior to giving birth they become solitary. Females give birth in a burrow, which is important in regulating the body temperature of the piglets, since young warthogs can not maintain their own body temperature the first few days of life. Young warthogs spend six to seven weeks in the burrow before venturing out with the mother. Male warthogs do not leave their mother until they are 2 years of age. Female warthogs leave their mother when they are sexually mature, but may return to the sounding later in life.

Breeding interval: Common warthogs breed once yearly.

Breeding season: Common warthogs breed under seasonal climatic conditions associated with rainfall. Mating peaks occur 4 to 5 months after the end of the rains.

Range number of offspring: 1 to 7.

Average number of offspring: 3.

Range gestation period: 170 to 175 days.

Average gestation period: 172 days.

Average weaning age: 21 weeks.

Range time to independence: 18 to 24 months.

Range age at sexual or reproductive maturity (female): 18 to 20 months.

Range age at sexual or reproductive maturity (male): 18 to 20 months.

Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); viviparous

Average birth mass: 660 g.

Average number of offspring: 3.

Common warthog sows isolate themselves in burrows to give birth, then stay undergroud with the altricial piglets for the first week. Piglets remain in the den for the first 6 to 7 weeks, and the sow returns often to nurse them. Piglets accompany the mother everywhere after the 6 to 7 weeks in the den. They are weened at about six months. Other sows in the sounding may nurse the young if they are closely related. Offspring may stay within the sounding for up to two years. Males do not play a role in parental care.

Parental Investment: altricial ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Female); pre-weaning/fledging (Provisioning: Female, Protecting: Female); pre-independence (Provisioning: Female, Protecting: Female); post-independence association with parents; extended period of juvenile learning

Currently common warthogs are not a protected species, but many populations are in serious decline due to overhunting in unprotected areas. Wildlife reserves are trying to protect warthogs, but outside of these areas there are no regulations on hunting. Several zoos have tried captive breeding with very little success.

US Federal List: no special status

CITES: no special status

IUCN Red List of Threatened Species: least concern

Common warthogs are known to cause damage to various crops, such as rice-fields and peanut crops. Cattle ranchers also see common warthogs as competitors for grazing in southern Africa. Common warthogs are suceptible to diseases which may be transmitted to domestic pigs, such as the tick-borne African swine fever virus. They also are a host of the tsetse fly, which can cause African sleeping sickness in humans.

Negative Impacts: injures humans (carries human disease); crop pest; causes or carries domestic animal disease

Common warthogs are valued for their meat, both for local consumption and trade in cities. Common warthogs are easy to hunt and have a potential of increasing population size by 39% annually, which makes them popular on game ranches. Rooting by common warthogs may also help to churn up soil and aerate the land, which in turn aids in plant growth. They are also a source of food for birds, such as red-billed and yellow-billed oxpeckers, that eat parasites off of their bodies.

Positive Impacts: food ; body parts are source of valuable material