The bearded pigs

One of the most remarkable pigs has to be the Bornean bearded pig Sus barbatus, one of two currently recognised bearded pig species. The other is the much smaller, shorter-faced Palawan bearded pig S. ahoenobarbus of the Philippines: genetic work suggests that S. ahoenobarbus is not a close relative of S. barbatus, but actually closer to the Celebes warty pig S. celebensis and other Philippines pigs (Lucchini et al. 2005). S. barbatus occurs on Sumatra, Bangka, the Riau archipelago and the Malay Peninsula as well as Borneo. There are two subspecies: S. b. barbatus has long cheek beards while S. b. oi has more wiry-looking snout hair. Molecular work confuses the distinction between these two forms, since Sumatran populations supposed to belong to S. b. oi are actually closer to the nominate Bornean population that to Malaysian populations of S. b. oi (Lucchini et al. 2005, p. 33).

One hypothesis for the evolution of Sus proposes that the bearded pigs and the Java warty pig S. verrucosus are the sister-group to a clade that includes the Wild boar S. scrofa and Celebes warty pig S. celebensis. Supposedly, members of the bearded pig lineage can be distinguished from members of the wild boar lineage by their especially elongate snout and 'saw-edged' fronto-nasal suture (Groves 1983, 1997). Conspicuous differences in size between the bearded pig populations of Sumatra, Borneo and elsewhere meant that particularly big individuals collected on Borneo were initially thought to represent an additional species; S. gargantua Miller, 1906.

Comparatively little is known about the ecology and behaviour of bearded pigs. They're reportedly migratory across part of their range, moving back and forth between areas during the year, and sometimes gathering in huge herds of hundreds of animals (Groves 1981). I'd like to know more about what they do with all that crazy snout hair, but this subject doesn't seem to have been much explored in the literature. It seems to be sexually dimorphic, with males having hairier snouts and cheeks.

These photos were taken at Berlin Zoo by Markus Bühler. Berlin Zoo includes quite a few neat bits of signage and artwork: the sign below does a nice job of illustrating some of the diversity present in the wild pigs of south-east Asia. As you can see, this diversity is pretty impressive. The taxonomy of these pigs has been much discussed and debated and how many of the various forms are regarded as 'subspecies' or 'species' remains the topic of disagreement (see Groves 1997, 2001). It's an important issue, since many of these pigs are threatened and of great conservation interest.

For previous Tet Zoo articles on pigs, see...

• The legend of Hogzilla
• Traumatic anal intercourse with a pig
• The deer-pig, the Raksasa, the only living anthracothere... welcome to the world of babirusas
• Are anthracotheres alive and well and living on Sulawesi? No, but it was a nice idea. Babirusas, part II
• What's with the bizarre curving tusks? Babirusas, part III
• When babirusas fight (babirusas, part IV)
• This little piggy went ploughing (babirusas, part V)
• The many babirusa species (babirusas, part VI)
• Laissez-faire lumping under fire? (babirusas, part VII)
• Babirusas can get impaled by their own teeth: that most sought-after of objects does exist! (babirusas, part VIII)
• The author caricatured. His trusty steed: a babirusa!
• Possibly the world's first knitted babirusa
• A close-up look at a Hairy babirusa
• Mystery pigs of tropical Asia, and capturing them on film

Ref - -

Groves, C. P. 1981. Ancestors for the Pigs: Taxonomy and Phylogeny of the Genus Sus. Technical Bulletin 3, Department of Prehistory, Research School of Pacific Studies, Australian National University, pp. 96.

- . 1983. Pigs east of the Wallace Line. Journal de la Société des Océanistes 77, 105-119.

- . 1997. Taxonomy of wild pigs (Sus) of the Philippines. Zoological Journal of the Linnean Society 120, 163-191.

- . 2001. Taxonomy of wild pigs of southeast Asia. Asian Wild Pigs News 1 (1), 3-4.

Lucchini, V., Meijaard, E., Diong, C. H., Groves, C. P., & Randi, E. 2005.Journal of Zoology, 266, 25-35

Lucchini, V., Meijaard, E., Diong, C. H., Groves, C. P. & Randi, E. 2005. New phylogenetic perspectives among species of South-east Asian wild pig (Sus sp.) based on mtDNA sequences and morphometric data. Journal of Zoology 266, 25-35. [Have added the same ref twice as cannot get research blogging to behave itself.]