Sus barbatusbearded pig

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Geographic Range

Sus barbatus, commonly known as Bearded Pigs, are found in Malay Peninsula, Riau Archipelago, Sumatra, Bangka, Borneo and Karimata Island to the south, Sibutu and Tawitawi islands in the Sulu Archipelago, Balabac and Palawan and the Calamian islands in the western Philippines.

Habitat

Bearded Pigs inhabit rainforests, mangrove thickets, and secondary forests.

Physical Description

The Bearded Pig has the slimmest torso and longest head of all the living pigs. Distinguishing characteristics include two pairs of warts on the face with the first pair covered by the beard hair, thin whiskers on the face, and a two-rowed tail tuft. Pigs in general are medium sized artiodactyls with large heads, a short neck, and a powerful and agile body covered with a coarse bristly coat of hair.

The Bearded Pig has a dark brown-gray coat with a distinctive white beard on the face. It has small eyes and fairly long ears, corresponding with a well developed sense of hearing. The snout ends in a mobile disk-shaped structure that bears the nostrils. The snout is prominent and the sense of smell is well developed. The snout has on it a set of tusks formed by the lower canine teeth.

All pigs walk on the third and fourth digit of each foot, while the second and fifth digits are reduced in size and free from touching the ground.

Body length is 3.3-5.5 ft. Tail length is 8-12 in. Shoulder height is 2.4-2.8 ft.

  • Range mass
    41 to 150 kg
    90.31 to 330.40 lb

Reproduction

Sexual maturity is reached at roughly 18 months, although most males do not gain access to receptive famale until reaching physical maturity at four years of age. The bearded pig along with other pigs of the genus Sus produce lip gland pheromones and a salivary foam during courtship. During courtship the male chants while nudging the female's flanks and sniffing her genital region. The male repeatedly attempts to rest his chin on the females rump. In fully receptive females, the male chin resting on her rump stimulates her to stand in the position of copulation. Mating can last up to ten minutes, during which time the spiral penis fits into the grooved cervix and a plug is formed after copulation.

The gestation period lasts roughly four months. When a pregnant female is ready to give birth, she leaves the herd and builds a litter nest on an elevation in the thicket. This nest can have a diameter up to 6 feet and a height of up to 3 feet. It is made of fern fronds, twigs, and dry palm fronds. On the litter nest, 2-8 young are born. In Borneo the number of young is usually only two or three. This small litter size is interesting considering the mother has five pairs of nipples. The coat of the infants is striped, with a dark brown stripe down the middle of the back and three yellowish and three dark brown stripes down the length of each flank. The piglets remain in the nest for ten days before following the mother. Weaning occurs at three months of age, but the piglets remain with their mother for roughly a year.

  • Key Reproductive Features
  • gonochoric/gonochoristic/dioecious (sexes separate)
  • sexual
  • Average number of offspring
    4
    AnAge
  • Average gestation period
    122 days
    AnAge

Lifespan/Longevity

  • Average lifespan
    Status: captivity
    16.2 years
    AnAge

Behavior

For the majority of the year, Bearded Pigs live in one location in a stable family group. They are active during the day aside from times of migration, when they switch to activity at night. Bearded Pigs are unique among the pigs in the extensive migrations that they take. Several hundred animals join together for the purpose of migration. Yearlings have never been observed in the migrating herds, and it is probably for this reason that reproduction is timed so that yearlings are grown at the time of the annual migration. The migrating herds are led by old boars (male pigs). Travel is done at night on wide paths, which are well worn. During the day the pigs retreat to the thickets. The Bearded Pigs always travel by the same route and at the same time of year. During migration, the pigs are much less shy than usual. It is not clear whether the migrations are in response to variations in food supply or due to a regular migratory cycle.

Communication and Perception

Food Habits

The Bearded Pig utilizes its long snout to dig in the ground for earthworms and roots. Fruit and gum tree seedlings are also part of the diet. Bearded Pigs often follow groups of macaques to feast upon the fruit that the macaques let fall to the ground. On the coast, they have also been known to feed upon dead fish that wash ashore.

Economic Importance for Humans: Positive

Due to their lack of shyness during migration and predictable times and routes of migrations, Bearded Pigs are easy prey for native humans. The natives wait along the borders of the migratory routes and hunt the pigs as they come along. The pigs travel in large herds and are relatively defenseless and unable to flee. The Beared Pig is used by natives as a dependable source of meat once a year.

Conservation Status

Although the number of Bearded Pigs has declined in recent years due to habitat desruction, it is still fairly common. No exact estimates of population numbers were found.

Other Comments

While the Beared Pig has been extensively studied in terms of being a source of meat for natives, not much else seems to be known about them. Not since the middle of this century has a Bearded Pig been kept in captivity, and consequently very little is known about their reproductive behavior. There also is conflicting information about the size and weight range of the Bearded Pig. For example, three different resources listed the wieght in kg as: 41-120, 100, 150. There is also a lack of information concerning sexual dimorphism and the average lifespan of the animal.

Contributors

Nicole Knibbe (author), University of Michigan-Ann Arbor, Phil Myers (editor), Museum of Zoology, University of Michigan-Ann Arbor.

Glossary

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

chemical

uses smells or other chemicals to communicate

endothermic

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

forest

forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.

motile

having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.

oriental

found in the oriental region of the world. In other words, India and southeast Asia.

World Map

rainforest

rainforests, both temperate and tropical, are dominated by trees often forming a closed canopy with little light reaching the ground. Epiphytes and climbing plants are also abundant. Precipitation is typically not limiting, but may be somewhat seasonal.

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

tactile

uses touch to communicate

References

1984. Encyclopedia of Mammals. New York: Facts On File Inc..

1990. Grzimek's Encyclopedia of Mammals. New York: McGraw Hill Publishing Company.

Corbet, G., J. Hill. 1992. The Mammals of the Indomalayan Region. New York: Natural History Museum Publications.

Harrison, J. 1964. Mammals Of Sanah. Singapore: The Sabah Society.

Medway, G. 1977. Mammals Of Borneo. Kuala Lumpur: Monographs of the Malaysian Branch of the Royal Asiatic Society.

Medway, G. 1969. The Wild Mammals Of Malaya. London: Oxford University Press.