Babirusas are largely diurnal, with a tendency to be more active in the morning when they feed. They are swift runners, weaving paths through the forest, and are also good swimmers, being able to swim to off-shore islands. They enjoy wallowing in mud baths like other pigs though other behaviours differ; The babirusa rarely use their snouts for rooting out food like other pigs, and they sharpen their lower tusks on tree trunks rather than on upper canines as other pigs do (2). They have an excellent sense of hearing and smell, which is invaluable in a thick forest environment, and have an omnivorous diet, feeding mainly on fruits, fungi, leaves, insect larvae, nuts and small mammals (2). Adult males are primarily solitary, while females form small groups of one or two females and their young (3). They have a slow reproductive rate compared to many other members of the pig family, with females bearing one or two piglets per litter in a nest of branches and leaves (7). The young are weaned at six to eight months and reach sexual maturity after one to two years; individuals are known to live up to 24 years (2).
This is one of the world's most bizarre looking mammals. Indeed, so bizarre is this animal's appearance that it has inspired some Indonesian people to make demonic masks based on them and even offer the animals themselves as gifts to visitors (5). Its name, babirusa, means 'pig-deer' and its peculiar appearance has lead local people to confer mythical properties to it (6). Babirusas are in fact members of the pig family, and the only living representatives of the subfamily Babyrousinae
(7). Its common name comes from its pig-like rounded body, and the highly distinctive tusks of males. These tusks are in fact upper and lower canine teeth which grow vertically and curve e backwards towards the forehead; the upper tusks passing through the skin of the snout These dramatic features may grow to 30 cm in length, though they usually absent or much smaller in females (3). The babirusa's body is rounded, with a mostly hairless hide which ranges in colour from grey to brown, with lighter underparts (3). Adult mainland babirusas often have large folds of skin on the neck and belly, with thinly distributed yellow hairs (3); whereas the nominate form from Buru and Sula Islands is notable in having a short hairy coat – hence being referred to as the 'hairy' or 'golden' babirusa. The young are also uniformly brown in colour rather than striped like most other wild pig offspring (8).
This genus has a very limited distribution, with the Sulawesi babirusa, Babyrousa celebensis
, being endemic to the island of Sulawesi, the Togian Islands babirusa, Babyrousa togeanensis
, being endemic to the neighbouring Togian Islands, and the hairy or golden babirusa, Babyrousa babyrussa
, being found on Buru and Sula Islands of Taliabu and Mangole; all of which are in Indonesia (2) (4) (7) (9).