Perception Channels: tactile ; chemical
The forest hog is rated 3-4 by IUCN. This means that it has a restricted distribution, is threatened by habitat destruction, hunting pressure or other ecological pressure, however populations are not declining. The subspecies Hylochoerus mienertzhagheni mienertzhagheni has the smallest range, but appears to be relatively secure (Oliver 1993).
IUCN Red List of Threatened Species: least concern
The forest hog is a symptomless carrier of African Swine Fever (ASF), which is lethal to domestic pigs. This disease is transmitted by a tick called the tampan. These suids also can carry the trypanosomes for sleeping sickness (ngana) that is transmitted by the tse-tse fly to livestock and humans. They also transmit rinderpest and are responsible for significant crop damage (Macdonald 1995, d'Huart 1993).
The forest hog is an easy target for hunting, and although among some peoples of the Congo, the eating of H. mienertzhageni is considered to cause calamity, the species is hunted in much of its range, not only for subsistence, but for commercial meat markets. There is also some trade for the ivory of its tusks, and hides were sometimes used for leather.
Positive Impacts: food ; body parts are source of valuable material
Herbivore: The forest hog is unable to root like other Suidae, but it can dig quite well with its tusks for roots and minerals. Otherwise, the forest hog grazes on grasses, sedges and herbage. Sometimes, these suids will ingest carrion or eggs. They also practice coprophagy (Estes 1991, d'Huart 1993).
Forest hogs are found in Africa, mainly in the equatorial forests and grasslands west, west of the Rift Valley. There are a few scattered small populations northeast of Lake Victoria, and several scattered larger populations from Nigeria to Senegal. There are three recognized subspecies, each with distinct ranges. The forest hog H. m. ivoriensis inhabits the area near the Ivory Coast, H. m. rimator lives in two areas near the west and central equatorial zone and coexists in the east equatorial zone with H. m. mienertzhagheni, the "true" giant forest hog. A potential fourth subspecies exists to the north of H. m. mienertzhagheni.
Biogeographic Regions: ethiopian (Native )
The giant forest hog prefers the dense shade of thickets and bushes. This suid ranges through a variety of forest types, including dry forests; humid, lowland forests; and montane forests (up to 3,800 m). H. meinertzhageni is most common near permanent water sources, especially where there is a thick understory cover. However, it does venture out into clearings and grasslands to feed.
Range elevation: 3800 (high) m.
Habitat Regions: tropical ; terrestrial
Terrestrial Biomes: savanna or grassland ; forest ; scrub forest
Average lifespan
Status: captivity: 3.0 years.
Standing approximately 1m high and 190 cm long, Hylochoerus meinertzhageni adults have a huge broad head, and males have pads of naked, inflated skin near their eyes. Both sexes have small, straight tusks that flare outward (to 30 cm) and teeth modified for grazing and browsing. The giant forest hog has large, pointed ears and bristly hair on its body and tail. Color is slate gray with some lighter hair on the face. The male's cheek pads contain scent glands, and this hog also has a preputial scent gland. Females are slightly smaller than males and have 4 mammae.
Range mass: 180 to 275 kg.
Average length: 190 cm.
Other Physical Features: endothermic ; homoiothermic; bilateral symmetry
Sexual Dimorphism: male larger
Gestation period: 151 days
Number of young: 2-11 precocial piglets
Breeding season: February to April and August to October
Birthing: January to March and July to September
Weaning: 9 weeks
Sexual maturity: 18 months
Life span: up to 18 years, with 5 years being the average
Juveniles accompany their mother very soon after birth, but remain under cover in nests of tall grasses and branches for at least a week, walking beneath the mother while in the open. Females may disperse as yearlings while males may stay until secondary sexual characteristics have appeared (Estes 1991, d'Huart 1993).
Key Reproductive Features: gonochoric/gonochoristic/dioecious (sexes separate); sexual
Average birth mass: 1250 g.
Average gestation period: 132 days.
Average number of offspring: 5.
Average age at sexual or reproductive maturity (male)
Sex: male: 517 days.
Average age at sexual or reproductive maturity (female)
Sex: female: 365 days.
The largest of the wild pig species in the world, the giant forest hog (Hylochoerus meinertzhangeni) inhabits dense forested areas and open savannahs of western and central Africa, native to several countries including (but not limited to) Cameroon, Congo, Uganda, Ethiopia and Sudan. However, distribution can best be described as patchy due to deforestation and agricultural cultivation of the original habitat (d’Huart and Yohannes, 1995). Tectonic activity (e.g. the Rift Valley) is partially responsible for the evolution of 3 subspecies of the forest hogs, with H. m. meinertzhangeni, found in Ethiopia, being considered the ‘true’ giant forest hog (d’Huart and Yohannes, 1995).
Males reach a shoulder height of approximately 1 m and can weigh up to 275 kg; heavier than the females by roughly 50 kg. Their diet consists of sub-canopy vegetation, such as tubers, roots and underground meristems (Cerling et al. 2004). These hogs can be found in groups or as solitary animals, leaving clearly distinguishable tunnelling systems throughout the forest undergrowth (Treves et al. 2010). With an average lifespan of 5 years in the wild, forest hogs reproduce all year. Females are sexually mature after 1.5 years of age and produce a litter of 2-4 piglets after a 3 month gestation period.
Due to its aggressive nature and territoriality it has escaped the trappings of domestication and as a bonus is rarely hunted for bush meat (although still hunted as trophies) since their flesh has an unpleasant taste (Jori and Bastos, 2009; d’Huart and Klingel, 2008). Overall, very little scientific research has been done regarding their ecology and behaviour, but they are listed as Least Concern by the IUCN Red List of Threatened Species due to their large distribution range, relatively few threats and high numbers in the wild.
The giant forest hog (Hylochoerus meinertzhageni), the only member of its genus (Hylochoerus), is native to wooded habitats in Africa and is generally considered the largest wild member of the pig family, Suidae; however, a few subspecies of the wild boar can reach an even larger size.[2] Despite its large size and relatively wide distribution, it was first described only in 1904. The specific name honours Richard Meinertzhagen, who shot the type specimen in Kenya and had it shipped to the Natural History Museum in England.[3]
The giant forest hog is, on average, the largest living species of suid. Adults can measure from 1.3 to 2.1 m (4 ft 3 in to 6 ft 11 in) in head-and-body length, with an additional tail length of 25 to 45 cm (9.8 to 17.7 in). Adults stand 0.75 to 1.1 m (2 ft 6 in to 3 ft 7 in) in height at the shoulder, and can weigh from 100 to 275 kg (220 to 606 lb).[4][5][6][7][8] Females are smaller than males. Females weigh a median of approximately 167 kg (368 lb), as opposed to males, which weigh a median of 210 kg (460 lb).[9] The eastern nominate subspecies is slightly larger than H. m. rimator of Central Africa and noticeably larger than H. m. ivoriensis of West Africa,[4] with the latter sometimes being scarcely larger than related species such as the bushpig with a top recorded weight of around 150 kg (330 lb).[8] The giant forest hog has extensive hairs on its body, though these tend to become less pronounced as the animal ages. It is mostly black in colour on the surface, though hairs nearest the skin of the animal are a deep orange colour. Its ears are large and pointy, and the tusks are proportionally smaller than those of the warthogs, but bigger than those of the bushpig. Nevertheless, the tusks of a male may reach a length of 35.9 centimetres (14.1 in).[8]
Giant forest hogs occur in west and central Africa, where they are largely restricted to the Guinean and Congolese forests. They also occur more locally in humid highlands of the Rwenzori Mountains, on the border between Uganda and the Democratic Republic of the Congo, and as far east as Mount Kenya and the Ethiopian Highlands. They are mainly found in forest-grassland mosaics, but can also be seen in wooded savanna and subalpine habitats at altitudes up to 3,800 m (12,500 ft).[5] They are unable to cope with low humidity or prolonged exposure to the sun, resulting in their being absent from arid regions and habitats devoid of dense cover.[5]
The giant forest hog is mainly a herbivore, but also scavenges.[10] It is usually considered nocturnal, but in cold periods, it is more commonly seen during daylight hours, and it may be diurnal in regions where protected from humans.[4] They live in herds (sounders) of up to 20 animals consisting of females and their offspring, but usually also including a single old male.[4] Females leave the sounder before giving birth and return with the piglets about a week after parturition. All members of the sounder protect the piglets, and a piglet can nurse from all females.[8] Boars fight by running head on into each other, followed by head pushing and attempts to slash the opponent with their lower tusks.[11]
As all suids of Sub-Saharan Africa, the giant forest hog has not been domesticated, but it is easily tamed and has been considered to have potential for domestication.[4] In the wild, though, the giant forest hog is more feared than the red river hog and the bushpig (the two members of the genus Potamochoerus), as males sometimes attack without warning, possibly to protect their group.[4] It has also been known to drive spotted hyenas away from carcasses, and fights among males resulting in the death of one of the participants are not uncommon.[8] Despite its size and potential for aggressive behaviour, they have been known to fall prey to leopards (probably almost exclusively large male forest leopards which are often larger than their savannah-dwelling equivalents) and clans of spotted hyenas. Although in some localities the lion may also be a predator of giant forest hogs, the species are usually segregated by habitat, as African lions do not generally occur in the densely forested habitats inhabited by this suid.[12][13]
The giant forest hog (Hylochoerus meinertzhageni), the only member of its genus (Hylochoerus), is native to wooded habitats in Africa and is generally considered the largest wild member of the pig family, Suidae; however, a few subspecies of the wild boar can reach an even larger size. Despite its large size and relatively wide distribution, it was first described only in 1904. The specific name honours Richard Meinertzhagen, who shot the type specimen in Kenya and had it shipped to the Natural History Museum in England.
