WARTHOG

WARTHOG, Phacochoerus aethiopicus

Classification: Order Artiodactyla, Family Suidae

Physical Description

General Description

Warthogs have been described both as 'incarnations of hideous dreams' and 'the most astonishing objects that have disgraced nature'. Although warthogs are certainly not glamorous animals, they are an integral and very interesting member of the African savanna.

Slimmer than other hogs, with level back and comparatively long limbs. The head is disproportionately large and has two pair of large warts. Length of head and body about 100cm; Male weighs 68-100 kg, height 68 cm; Female 45-71 kg, height 60 cm. On an average, a warthog’s lifespan extends up to 18 years.

Tusks

Tusks form a semicircle between the warts, pointing forward and upward. Upper Tusks average 20 cm for males and can grow up to 60 cm. Lower canines measure approximately 10 cm and are extremely sharp. Tusks are much shorter in females. The shorter tusks of the lower jaw are used as sharp weapons, while those of the upper jaw curve upward and inward in a semicircle. The upper tusks attain a length of more than 60 cm in some older males.

Warts

Warts are actually thickened skin and gristle that grow below the eyes. These two skin growths have no bony support or core and measure up to 3 cm long in males however are mere bumps in females and young.

Skin

The adult color is blackish, brownish, or grayish; the young are pinkish. The hide is almost hairless, with only a few hairs present on the cheeks and on the back where they form a mane. Cheek whiskers are white and shaped like tusks. The tail is 13 to 19 inches long, has a tuft of hair at the end, and is carried in a distinctive vertical position when the animal is moving. This amusing trait allows them to follow one another through long grass. The skin of the warthog resembles slate or clay in color and is very thick, often enabling the animal to escape being severely wounded.

Harderian glands in eye sockets leave dark stains on male's face.

WHERE IT LIVES

Distribution: They are widely distributed throughout western, central and eastern Africa, excluding the forests of the Congo Basin. They are also found throughout Namibia, Zimbabwe and Mozambique, in the open country of Africa south of the Sahara. This area includes the savanna of Ghana, Somalia, and South Africa.

Habitat: Savanna and Grassland, absent only from deserts, rainforest, and mountains above 10,000 feet (3000 m).

Warthogs are found in grasslands and sparse forests. They prefer the open plains of the savanna, with a nearby water source for drinking and wallowing. Despite this, water is not an essential habitat requirement. For shelter they use aardvark burrows or holes among rocks, which they back into in order to defend themselves from predators. Areas covered with short grass and with plenty of termite mounds, are the ideal Warthog habitat. They also utilize woodland and open scrub and are extremely partial to freshly sprouting grass following a burn. Warthogs avoid deserts, thick bush, tall grass and thickets and mountain forests.

ECOLOGY
A true savanna dweller that avoids dense cover and forest but depends on burrows to escape predators and temperature extremes, especially in infancy. Although warthogs dig quite well, using snout as shovel, most holes they use have been excavated by aardvarks.

FOOD AND EATING HABITS

The warthogs graze on short grasses, feed on fruits and carrion, and also dig up bulbs, roots, and tubers. The vast bulk of the warthog's diet is made up of grasses. They sometimes eat carrion and bark from trees. Specialized incisors allow them to pluck the growing tips of grass shoots. During dry periods, a warthog uses the top edge of its nose to dig grass rhizomes out of the sun-baked dirt. Warthogs generally feed while kneeling. Tusks are not used for foraging, but rather for defense. They drink and in hot, dry weather use wallows daily.

ACTIVITY
Unlike most wild pigs, warthogs are active in daylight. They may become nocturnal where they are hunted by humans. After traveling an average 7 km in daylight, females and young retire before dark into up to 10 secure sleeping burrows dotted within their home range, emerging the next morning to late during cold or rainy weather. Burrows are used by different sounders on a first-come, first-served basis. Boars are somewhat less diurnal; they often remain active for an hour or so after dark and later on moonlit nights. They stay up late to sniff out burrows occupied by sows in heat, returning to waylay them as they emerge next morning. They can run as fast as 55km/h. Their eyesight is poor but their sense of smell and hearing are acute.

SOCIAL SYSTEM

Generally gregarious animals, warthogs live in family groups in a territory that may be shared by more than one family. The population is divided into clans, each consisting of several bands and associated lone animals. Most bands (also called "sounders") contain 4-6 individuals, although groups of up to 40 have been reported. The members of these groups tend to have lasting bonds with one another, especially the females.

Sows live in clans of related individuals that share the same resources. Mothers and daughters with offspring up to 2 years old may stay in the same group or in different groups that share a traditional home range (average 430 acres, range 158-924 acres 172-420 ha]). Sounders typically number 5 or less and include only one sow with her young of the year, but many contain 2 mothers with their combined broods; sounders with 4 to 5 sows occasionally number up to 16 warthogs. Associated mothers suckle one another's young as a sign of kinship.

BEHAVIOUR

Warthogs are not territorial, but sometimes competition for resources and waterholes occurs. Warthogs communicate through vocalizations including grunts, growls, snorts, and squeals. These calls are used for greeting, contact maintenance, threats, warnings, and submissions. Submission is displayed by bowing the head low, having the mane lowered and ears flattened.

HOW IT MOVES

Warthogs have attained a top speed of 34 mph (55 kph) in emergencies, but warthogs not in a hurry prefer to trot characteristically with tail straight up like an antenna. They lie down and get up like ruminants, not swine, kneeling on forelegs in lying and raising the hindquarters first in rising. Feeding warthogs routinely graze and root while resting on their callused knees.

REPRODUCTION

Warthogs reach sexual maturity at 18-20 months of age, but most males do not usually mate until they are 4 years old. Males are generally solitary, only joining a group during breeding periods. In such a period, males engage in ritualized fights for access to females. The display of aggression when in mating season: Grunting and growling they push and box with their blunt upper tusks and snout (no slashing or stabbing with their lower tusks). Interestingly, their warts absorb the blows and serves to protect their eyes. The breeding time of the warthog is synchronized with the local rainy seasons. These rainy seasons vary in month depending on the area. Females give birth to litters consisting of 1-8 young after a gestation period of 170-175 days. The young are born in a hole in the ground. These holes are either natural or made by aardvarks. They suckle for up to 4 months, but leave the burrow a week after they are born to feed on grass.

OFFSPRING AND MATERNAL CARE

Sows isolate to farrow, then stay underground nurturing 2 to 5 (rarely 6-8) tiny, hairless piglets for the first week. Except for brief excursions or to change dens, piglets remain in burrow 6 to 7 weeks, after which they accompany their mother everywhere, filing behind her in a fixed order. Begin grazing within 2 to 3 weeks but continue nursing briefly every 40 minutes or so from 3 to 6 weeks; weaned by 6 months.

There is a large degree of prenatal loss of fetuses and a large number of piglets are stillborn or die shortly after birth. Furthermore, little warthogs are exceptionally sensitive to temperature fluctuations and habitat changes and as many as 50% usually do not make it past the first six months.

PREDATORS

Being slower with less endurance than most savanna ungulates, burrows are essential sanctuaries when chased by cheetah, wild dog, or spotted hyena, However, cheetahs think twice before tackling adult warthogs, are often chased by mothers defending offspring. Fleeing juveniles pile headlong into a hole; adults reverse direction at last instant, can then use their tusks on pursuers that try to follow. Up to 2 offspring succumb to predators and other causes the first year.

Although burrows keep warthogs safe at night, emerging in the morning can be risky since lions are clever enough to sniff out occupied burrows and patient enough to wait in ambush at breakfast time.

CONSERVATION

Warthogs are of special concern because they have been hunted for many years and their populations have declined as a result. Since the safari hunts of the late 1800's, warthogs have been sought after for their tusks and for their energetic chases. As a result, they have been eliminated from most of South Africa, but they remain in moderate numbers in the rest of their original range. Relatively recently, conservation laws have been passed in several countries in order to protect warthog populations.

Fun Facts

1. Warthogs travel in groups called sounders consisting of 1 or 2 sows and young offspring. Males usually travel alone.

2. Boars have more prominent warts than sows. They are primarily used to protect the face during fights.

3. Warthogs use burrows for shelter and when entering, the hogs back in. This enables them to defend themselves. In the mornings, warthogs burst out of their burrows at top speed to get a running start on any predators that may be lurking nearby.

4. Although they look fierce, warthogs would rather run than fight. But they can be fierce opponents if forced.

5. In Swahili, the Warthog is known as “Ngiri” - Naked swine of the savanna.

SOURCES

http://www.africaonline.co.ke/AfricaOnline/groups/parks/Warthog.html

Britannica

http://nw1.newsweek.com/nw-srv/inetguide/iguide_4402959.html

The University of Michigan

http://animaldiversity.ummz.umich.edu/accounts/phacochoerus/p._aethiopicus

SeaWorld Busch Gardens

http://www.seaworld.org/animal_bytes/warthogab.html

WebCam AfriCam Services

http://www.africam.co.za/glossary/animals/warthog.html