Phacochoerus africanus
common warthog
(Also: warthog)

Warthogs (Phacochoerus africanus) are found outside forested areas in Africa, from Mauritania to Ethiopia and south to Namibia and eastern South Africa. ("Grzimek's Encyclopedia of Mammals", 1989; "Walker's Mammals of the World", 1991; Grubb, 1993)

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. ("African Wildlife Foundation", 2005; "Sea World/Busch Gardens", 2005; "Walker's Mammals of the World", 1991; Vercammen and Mason, 1993)

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. ("African Wildlife Foundation", 2005; "Grzimek's Encyclopedia of Mammals", 1989; "Sea World/Busch Gardens", 2005; "Walker's Mammals of the World", 1991; Randi et al., 2002)

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. ("African Wildlife Foundation", 2005; "Sea World/Busch Gardens", 2005; Boshe, 1984)

Common warthogs live in family groups called soundings. A sounding usually consists of females and their young. Males usually disperse after 2 years of age and become solitary or form bachelor groups. Females stay in a sounding except when they are pregnant. Soundings can consist of up to 18 members. Common warthogs are primarily diurnal and take refuge at night in burrows. Warthogs commonly utilize aardvark holes for sleeping at night. They cope with high temperatures by wallowing in mud or water and cope with low temperatures by sheltering in burrows and huddling together. They are primarily diurnal when there is not human disturbance. ("African Wildlife Foundation", 2005; "Grzimek's Encyclopedia of Mammals", 1989; "Walker's Mammals of the World", 1991; Vercammen and Mason, 1993)

Home Range

Common warthogs do not exhibit territorial behavior. Different groups of warthogs have extensive overlap of home ranges. Warthogs share resting, feeding, drinking, and wallowing sites. Occassionaly warthogs shift their home ranges in response to seasonal water shortages. Home range size of common warthogs can vary from 0.62 km^2 to 3.3 km^2. (Cumming, 1970)

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. ("Grzimek's Encyclopedia of Mammals", 1989; "Walker's Mammals of the World", 1991)

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. ("African Wildlife Foundation", 2005; "Grzimek's Encyclopedia of Mammals", 1989; "Sea World/Busch Gardens", 2005; "Walker's Mammals of the World", 1991; Cumming, 1970)

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. ("Grzimek's Encyclopedia of Mammals", 1989; Vercammen and Mason, 1993)

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. ("Sea World/Busch Gardens", 2005; Anderson et al., 1998; Vercammen and Mason, 1993)

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. (Anderson et al., 1998; Vercammen and Mason, 1993)

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. ("Sea World/Busch Gardens", 2005; Vercammen and Mason, 1993)

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. (Vercammen and Mason, 1993)