Babyrousa babyrussababirusa

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Geographic Range

Indonesia: Sulawesi, the Togian and Sula islands, and Buru island in the Moluccas (the latter two apparently by introduction)

Habitat

The babirusa prefers moist forests and canebrakes near the shores of rivers and lakes. They avoid dense shrub vegetation.

Physical Description

Length: Head and body, 85-110 cm; tail, 20-32 cm.

Height: 65-80 cm at shoulder

The babirusa has a rounded body, somewhat pointed snout, and relatively long, thin legs. Males are larger than females. Depending on the subspecies, the skin may be rough and brownish gray with only a few dark bristles (B. b. celebensis), brown to black coat, markedly lighter on the underside (B. b. togeanensis), or long, thick golden cream-colored and/or black coat (B. b. babyrussa). The skin often has large folds or wrinkles. (Parker, 1990)

The babirusa's most dramatic physical features are its tusks. The upper canines of males never enter the mouth cavity but rather grow upward, pierce through the top of the snout and curve backward toward the forehead. They may reach a length of 30 cm. In females, the upper canines are small or absent. These tusks are brittle and loose in their sockets, apparently useless as offensive weapons, but they may help to shield the face while the daggerlike lower tusks are used in fighting. There is also evidence that on some islands these tusks are used to interlock and hold an opponent's tusks, and on other islands they are used for butting.

  • Range mass
    43 to 100 kg
    94.71 to 220.26 lb

Reproduction

The babirusa mating system has been described as a "roving dominance hierarchy" among the males in an area. (Macdonald, 1984) Males use their tusks to fight with other males for the right to mate with several females. (Houston, 1997) Babirusa have a gestation period of 150-157 days, and 1 or 2 young per pregnancy is typical (unusually few for suids). Young weigh between 380 and 1050 g. at birth. Young are usually born in the early months of the year. They are more precocial than the young of other suids, beginning to eat solid food 3-10 days after birth; weaned at 6-8 months. Young attain sexual maturity at 1-2 years. In captivity, babirusa have lived up to 24 years.

  • Key Reproductive Features
  • gonochoric/gonochoristic/dioecious (sexes separate)
  • sexual
  • Average number of offspring
    1.3
    AnAge
  • Average gestation period
    153 days
    AnAge
  • Average age at sexual or reproductive maturity (female)
    Sex: female
    548 days
    AnAge
  • Average age at sexual or reproductive maturity (male)
    Sex: male
    548 days
    AnAge

Lifespan/Longevity

Behavior

The babirusa is apparently diurnal, active primarily in the morning. About half of their time is spent lying down, usually sleeping. They are swift runners, and often swim in the sea to reach offshore islands. They construct straw nests and wallow in mud. Unlike other suids, the lower tusks are not kept sharp by wearing against the uppers; male babirusa actively hone their tusks on trees. When excited, they clatter their teeth.

Adult male babirusa are primarily solitary, while adult females are often found in small family groups, with a few young and/or sub-adults. Like other suids, they are quite vocal, with a limited vocabulary of low moans or grunts.

Like other wild pigs, babirusa are not believed to be particularly territorial, although they will mark their home ranges in various ways. (Macdonald, 1984). For example, adult males in captivity have been observed to engage in "ploughing". When put into empty, sand-filled enclosures, they will put their snouts deep into the loose soil, kneel, and slide forward on their chests. They salivate copiously while "ploughing", suggesting that this unique behavior serves a scent-marking function. (Leus, 1996)

Communication and Perception

Food Habits

The babirusa, unlike most other suids, does not appear to use its snout to root for food. It is also a more specialized feeder than most suids, primarily eating foliage, fallen fruit, and fungi.

Economic Importance for Humans: Positive

Indonesian natives hunt the babirusa for food. They are also frequently captured young and tamed.

Babirusa are of interest to medical researchers, because the babirusa tusk is the only permanent natural percutaneus (passing through the skin, such as by puncture) structure. When percutaneus devices such as catheters are implanted in humans, the epidermis generally does not adhere well to the device, posing a risk of infection at the site. Researchers hope to learn how to avoid this complication by studying the babirusa, where the problem does not occur. (Knabe, 1999)

Economic Importance for Humans: Negative

None found.

Conservation Status

Excessive hunting and habitat loss have caused a substantial decline in babirusa populations, despite longstanding legal protections. The wild population is estimated at about 4000 individuals, spread across several islands. In addition to humans, they are preyed upon by feral and domestic dogs.

The species has always been rare in zoos, but seems to breed readily in captivity. The largest breeding group is in the zoo in Surabaya, Indonesia. The Stuttgart Zoo coordinates a European Maintenance Breeding Program for the babirusa.

Other Comments

Despite the external resemblance, recent studies of fossils have suggested that the babirusa may in fact be more closely related to hippopotami than pigs. However, comparison of anatomical features (e.g., the heart) offers evidence to the contrary (MacDonald, 1994). It is often placed in its own subfamily, Babyrusinae. Its closest relative is believed to be a European pig that became extinct 35 million years ago. (Houston, 1997)

According to native legend, the babirusa hooks its tusks over a low branch at night, to support its head while it sleeps (or, in more imaginative versions, hangs itself from trees to sleep). The name "babirusa" means "pig deer", referring to the resemblance between its tusks and a deer's antlers.

Numerous links to pictures of babirusa may be found at http://www.pathcom.com/~dhuffman/babirusa.html.

Contributors

Ati Tislerics (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

sexual ornamentation

one of the sexes (usually males) has special physical structures used in courting the other sex or fighting the same sex. For example: antlers, elongated tails, special spurs.

tactile

uses touch to communicate

References

Houston, B. 1997. "The Babirusa: Setting the Standard for Bizarre" (On-line). Accessed October 14, 1999 at http://www.stlzoo.org/content.asp?page_name=babirusa.

Huffman, B. 1999. "Babirusa" (On-line). Accessed October 6, 1999 at http://www.pathcom.com/~dhuffman/babirusa.html.

Knabe, C., C. Grosse-Siestrup, U. Grosse. 1999. Histologic evaluation of a natural permanent percutaneous structure and clinical percutaneous devices. Biomaterials, 20(6): 503-510.

Leus, K., K. Bland, A. Dhondt, A. MacDonald. 1996. Ploughing behavior of Babyrousa babyrussa (Suidae, Mammalia) suggests a scent-marking function. Journal of Zoology (London), 238(2): 209-219.

Leus, K., P. Vercammen. 1996. Behaviour of a male and female babirusa (Babyrousa babyrussa, Suidae, Mammalia) during the first five days after their move to a semi-natural enclosure. Zoologische Garten, 66(3): 133-155.

MacDonald, A. 1994. The placenta and cardiac foramen ovale of the babirusa (Babyrousa babyrussa). Anatomy & Embryology, 190(5): 489-494.

Macdonald, D. 1984. The Encyclopedia of Mammals. New York, NY: Facts on File Publications.

Nowak, R. 1997. "Walker's Mammals of the World Online" (On-line). Accessed October 6, 1999 at http://www.press.jhu.edu/books/walkers%5Fmammals%5Fof%5Fthe%5Fworld/prep.html.

Parker, S. 1990. Grzimek's Encyclopedia of Mammals, vol. 5. New York, NY: McGraw-Hill.

Patry, M., K. Leus, A. MacDonald. 1995. Group structure and behavior of Babirusa (Babyrousa babyrussa) in northern Sulawesi. Australian Journal of Zoology, 43(6): 643-655.