Sus ahoenobarbus was originally described as a subspecies of Bearded Pig S. barbatus, but upgraded to full species because of its distinct characteristics. A phylogenetic analysis based on two mitochondrial DNA cytochrome b fragments (mtDNA cyt b) suggested that S. ahoenobarbus was more closely related to the Visayan Warty Pig S. cebifrons than to the species it was originally thought to be a subspecies of, S. barbatus. Morphologically it is, however, more similar to S. barbatus, as evidenced by their conspicuous beards and absence of the prominent manes and mandibular facial warts characteristic of the Philippine warty pigs. Also the chromosome number, which is 38 in S. ahoenobarbus, S. barbatus and almost all other Sus spp, but 36 in S. cebifrons and S. philippinensis, suggests a closer affinity of S. ahoenobarbus to S. barbatus. As was stated in the taxonomic review of the species by Groves, "there is absolutely no doubt that this form is a dwarf barbatus". Still in view of more recent evidence, it is unclear whether there are issues of data interpretation underlying this apparent contradiction in phylogenetic affinity, or whether there is another explanation. For example, hybridization may have occurred between barbatus and cebifrons, so that ahoenobarbus maintains characteristics of both species. Until further research is conducted, the phylogenetic affinities of S. ahoenobarbus remain unclear.

This species is endemic to the Philippines, where it is restricted to the ‘Palawan Faunal Region’ extending from Balabac and associated islands in the extreme south-west, all of Palawan Island and its associated offshore islets, as far as the Calamian Islands in the extreme north-east. However, this region therefore also constitutes the easternmost extension of the ‘Sunda Shelf’ and was intermittently connected by land bridges to Borneo by sea level changes during consecutive Pleistocene glaciations. The species is known from many locations on the Palawan mainland, and is confirmed or reported from all other larger islands in the region, including Balabac and Bugsuk in the south, and Dumaran, Linacapan, Coron, Culion, Busuanga and Calauit Islands in the north. The species remains relatively widely, if increasingly patchily, distributed. It also occurs in a variety of primary and secondary habitats, ranging from lowland and mid-montane rainforests forests (from 0 to c. 1500 m asl) to drier open woodland and grasslands. It also frequents drier limestone and mangrove forests in coastal areas, and occurs in cultivated and managed areas.

Body length 1–1.6 m, shoulder 1 m, weight up to 150 kg. This species is smaller than S. barbatus, and has a shorter facial skeleton. The hair is thin, bristly, and blackish-brown over most of the animal, but adults have a distinct mane of longer whitish hairs extending from crown to rump, a characteristic ‘beard’ of long white hairs on the cheeks and jowls, extending in a band across the snout; the latter contrasting with black hairs around the eyes, forehead and more anterior parts of the snout, providing a ‘mask-like’ appearance. Infants lack manes and beards and are generally far less distinctly marked, except for three horizontal bands of orange-coloured hair extending from their necks to their hind-quarters; the lower band also being much broader and therefore extending over most of the lower sides of their bodies.

Although this has not been studied, it is thought that ecologically S. ahoenobarbus is similar to the Bearded Pig S. barbatus from Borneo, which consumes roots, fungi, invertebrates, small vertebrates and a great range of plants, and especially favors lipid-rich fruit of the Fagaceae and Dipterocarpaceae families.

Little is known, except that the species is most often seen/reported to be active in the early mornings and late afternoons in relatively undisturbed areas, but tends to be almost exclusively nocturnal in areas where hunting and other anthropogenic disturbances are commonplace.

Almost nothing is known. Most local hunters and other informants report that they seldom see more than two or three individuals together, though it is likely that larger natal family units and other socio-reproductive groups are maintained in less disturbed areas.

Nothing is known.

The species is listed as Vulnerable on The IUCN Red List. It is heavily hunted throughout most of its range, either for direct consumption or to be sold. 1 kg of pork fetches a price of about 60 Philippine Peso or about 1 US$ (2006 rate), or up to twice the price of domestic pork. Pigs are hunted throughout the year, but especially during forest tree fruiting periods (no specifics are known) when pigs gather to forage on fallen fruits, or in reprisal for their occasional raids on neighbouring forest gardens or other cultivation areas. Hunting methods include snares, low caliber rifles, and small, baited explosive devices known as ‘‘pig bombs’’; the latter being made of ‘ping-pong ball sized mixtures of gunpowder and shards of  porcelain , coated with fish paste of other strong-smelling baits to entice the pigs. These are buried on pig trails or around cultivated plants close to forest edges. They explode when they are unearthed and bitten into by foraging pigs; thereby killing the pigs or, more likely, causing horrendous wounds and producing trails that hunters with dogs can follow to collect the dead or dying animals the following day. S. ahoenobarbus is also threatened by encroachment into forest areas, whether via illegal ‘kaingin’ (i.e. slash and burn agriculture), mining or other commercial developments.

The species is legally protected by Philippine wildlife protection legislation. However, implementation of such legislation is generally poorly enforced and/or realistically unenforceable in most areas – including most designated ‘protected areas’. Priority requirements therefore include the more effective implementation of existing legislation, and addition of new protected areas in key areas, if possible designed to enable greater management control by local governmental authorities than is the case under the existing national protected areas system. Awareness campaigns are also important in that few hinterland communities are aware of any prevailing wildlife protection legislation or are careless of this owing to the generally chronic lack of enforcement by salient governmental authorities. This is especially the case in areas where ‘reprisals’ following occasional raids by pigs on cultivated crops in illegally encroached areas are likely to illicit sympathy and non-action from the responsible agencies. Such illegal activities are justified by corresponding claims of poverty and loss of livelihood, irrespective of the underlying illegalities, cruelties and highly dubious nature of any such claims (i.e. few, if any such claimants are in any economically sense dependant on hunting, but instead engage in such activities for predominately traditional/cultural and recreational reasons). 

Text adapted from: Meijaard, E., J. P. d'Huart, and W. L. R. Oliver. 2011. Family Suidae (Pigs). Pages 248-291 in D. E. Wilson, and R. A. Mittermeier, editors. Handbook of the Mammals of the World. Vol 2. Hoofed Mammals. Lynx Edicions, Barcelona, Spain.

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