THE STRANGE CASE OF THE BABIRUSA

The Babirusa (Babyrousa babyrussa) is probably the most remarkable of all suids in terms of appearance and other characteristics. It is native to the tropical rain forests of Sulawesi, Buru and Togian Islands of Indonesia. Some specialists describe three subspecies, depending on the island inhabited by each babirusa. These islands are found in Indonesia: Sulawesi, the nearby Togian and Sulu islands, and Buru Island in the Moluccas. Its presence on Buru and possibly Sula islands is a result of human introduction.

 The most striking feature at first sight is the morphology and position of their tusks. Differently from other swine, the tusks of Babirusa are not directed sideways out of the mouth, but upwards, and perforate the soft tissue of the snout, curving backward toward the forehead. Sometimes, inferior tusks grow long enough to perforate the mandible right below the beginning of the tusk. Some authors suggested that these strange tusks are used as weapons: the upper tusks have a general defensive function while lower tusks are used offensively. On the contrary, others affirm that the function of the tusks is unclear; tusks are rarely used in combat between males, possibly because the form in which they are inserted in the maxilla does not support the application of too much force.

Distribution of Babyrousa babyrussa. Actual distribution could be patchier.

The preferred habitats of the Babirusa are moist forests, canebrakes and the shores of rivers and lakes. Information on the diet of this species is anecdotal and not very well-known. Fruit have been reported to be the main dietary item for this species, but they also consume a wide variety of leaf, root, fruit and animal material. Some authors observed captive individuals browsing the leaves off trees.

Its jaws also seem to be strong enough to crack very hard nuts with ease, and the cranial muscular anatomy is very similar to that of Sus. Even though the species´ intestinal tract is similar to that of the domestic and wild pig (Sus scrofa), the stomach is more far more complicated. The Babirusa is likely to be a non-ruminant foregut-fermenting frugivore/concentrate selector, which is related to their relatively large diverticulum in comparison to other suid species. There are substantial differences in the presence of glands in the stomach, and endocrine cells in the digestive tract, suggesting adaptations to frugivory.

According to Nowak, the babirusa does not exhibit the rooting behavior typical of other suids. They do not seem to root with their snout as do Sus and Potamochoerus, probably due to the lack of a rostral bone in the nose. And if they do so, they just do it in mud and swampy ground. However, field reports are scarce, and the complete understanding of its rooting behavior is yet to be completely clarified; a comprehension that can aid in the conservation and management of this unique species.

This text has been adapted from the Msc Thesis of Ignacio Aguilar Lazagabaster "Microwear analysis on Suoid incisors: a new method to study faunal adaptive responses to the environmental changes which shaped Human Evolution" directed by Eugénia Cunha (University of Coimbra) and Jan van der Made (MNCN-CSIC). Find a link here:      https://estudogeral.sib.uc.pt/bitstream/10316/24669/1/Tese%20Mestrado%20Final%20Ignacio.pdf


Check also this video from the BBC´s Life of Mammals: