Sus philippensis, Linnaeus, 1758

Don E. Wilson & Russell A. Mittermeier, 2011, Suidae, Handbook of the Mammals of the World – Volume 2 Hoofed Mammals, Barcelona: Lynx Edicions, pp. 248-291 : 284

10.

Philippine Warty Pig

Sus philippensis

French: Sanglier des Philippines / German: Philippinen-Pustelschwein / Spanish: Jabali de Filipinas

Taxonomy. Sus celebensis var. philippensis Nehring, 1886 ,

Luzon, Philippines.

Sus philippensis was recognized formally as a distinct species in 1991, originally having been considered a subspecies of the Sulawesi Warty Pig (S. celebensis ) or the Bearded Pig (S. barbatus ). Initially, three subspecies were proposed: philippensis from Luzon and associated islands; mindanensis from Mindanao and associated islands; and oliveri from Mindoro. The latter subspecies was assigned later to full species level. Recent mtDNA studies have suggested that philippensis and mindanensis are distinct enough to be considered full species, but this has not yet been formally proposed. Two subspecies are actually recognized.

Subspecies and Distribution.

S. p. philippensisNehring, 1886 — LuzonandassociatedIs (Polillo, Catanduanes, and, formerly, Marinduque).

S. p. mindanensis Forsyth Major, 1897 — Mindanao and surrounding Is (Samar, Biliran, Leyte, Bohol, Camiguin, Basilan, and associated smallerIs).

Descriptive notes. No body measurements are available for this species. This is a species of Sus with karyotype 2n = 36, unlike other wild species, as well as domestic pigs, in which 37 or 38 chromosomes are more common. S. philippensis is generally blackhaired, with a prominent black mane (sometimes interlaced with white higher streaks in subspecies mindanensis) and gray skin, which sometimes appears whitish in color when extending over the well-developed preorbital warts. The latter characteristic and this species’ more prominent white jowl tufts readily distinguish it from other Philippine wild pigs. Philippine Warty Pigs have a long, full crown tuft and a nuchal mane that extends along the back in most individuals, especially adult males. Males have two pairs of warts; their gonial (lower jaw) hair tufts are very long and thick, and largely white or yellow. Adult sows also have distinctive white, but much thinner, gonial tufts. The skull has a deep, sharply bordered preorbital fossa. Compared to S. celebensis and the Eurasian Wild Pig (S. scrofa ), the facial skeleton is somewhat elongated but not as much as in S. barbatus or the Javan Warty Pig (S. verrucosus). The face is somewhat concave at the nasal root, with nasals slightly convex and the malar tuberosity greatly swollen. The braincase is high crowned, sloping downward to facial skeleton, and with the occipital crest extending backward. The anterior margin of the temporal fossa is perpendicularly above M? or just behind it. The foramen magnum is described as “teardrop-shaped.” The maxillary premolar rows curve outward anteriorly. M* is very short, with four major cusps and a small 5" cusp. The two subspecies are morphologically distinct. Subspecies philippensis has a grayish crown tuft with an anterior fringe that is directed forward. The facial warts are relatively large, and the whorls on the lower jaw are white. The skull size in males is relatively small, and the braincase is shortened and relatively flat-topped. Subspecies mindanensis closely resembles philippensis, but differs in the following features: the crest and mane are mostly black, but often distinctly intermixed with white or reddish-brown hairs, though the crown tuft may be white anteriorly; the forward-directed fringe is absent or less apparent in most individuals. The facial warts are small, though the lowerjaw tufts, usually yellow or yellow mixed with black, are prominent; they are much more developed in adult males than females. The skull size of mindanensis is also much larger in males than females, and the braincase more rounded in comparison to philippensis.

Habitat. The Philippine Warty Pig was formerly abundant from sea level up to at least 2800 m, in virtually all habitats, but now it is common only in remote forests. It was recently reported to be common in montane and mossy forest 925-2150 m elevation in Balbalasang-Balbalan National Park, Kalinga Province, Luzon, and a recent birding trip report found many pig wallows in the park. In the Kitanglad Mountain Range on Mindanao, signs of pigs were also seen in montane, mossy forest between 1800 m and 2000 m. A specimen taken in 1996 was found at 1100 m, and in another in 1960 at c. 1300 m, but it is unclear whether the species still survives at these elevations today in Kitanglad. Habitat information from other areas is scarce, butit is assumed that the species is now largely restricted to higher forests in remoter areas.

Food and Feeding. Nothing is known specifically about what the species feeds on in high elevation forests, but presumably it survives on a diet of tubers, fallen fruit, and invertebrates.

Breeding. Little is known. The species has seldom been bred in captivity, though a litter of five piglets was reported on one occasion.

Activity patterns. Little is known of the species’ circadian activity in remoter areas, but it is reported to be essentially nocturnal in areas subject to human disturbance.

Movements, Home range and Social organization. Nothing is known.

Status and Conservation. Classified as Vulnerable on The IUCN Red List because it is currently undergoing a drastic population decline, estimated to be more than 30% over a period of three generations, or about 21 years. This decline is inferred from the apparent disappearance of several populations and the effects of overhunting, habitat loss, and hybridization. S. philippensis is endemic to the Philippines, and occurs through most of the country except the Palawan Faunal Region (whereitis replaced by the Palawan Bearded Pig, S. ahoenobarbus), Mindoro (replaced by the Mindoro Warty Pig, S. oliveri), the Negros-Panay Faunal Region (replaced by the Visayan Warty Pig, S. cebifrons), and the Sulu Faunal Region (where it is apparently replaced by a closely related but as yet undescribed species of pig). Subspecies philippensis is confined to the “Greater Luzon Faunal Region.” Subspecies mindanensis is confined to the “Greater Mindanao Faunal Region.” Precise data on wild pig populations is lacking for most of these islands, particularly the smaller ones. The present status of S. philippensis may be inferred from the extent of remaining forest overits known ranges, the likely extent of hunting pressure, and other factors. The species was undoubtedly far more extensively distributed in the past, and most extant populations, particularly on the largerislands, are badly fragmented and declining. The species’ habitat is threatened by continued low-level illegal logging and agricultural expansion. Pig hunting continues throughout the remaining range of the species, including many (perhaps most) protected areas. Hunting is mostly practiced by local farmers and indigenous peoples in hinterland communities and by recreational hunters from cities. Both of these groups also sell any surplus meat, which usually commands at least twice the price of domestic pork in local markets and speciality restaurants. Efforts to reduce or discourage hunting are often compromised by generally negative attitudes towards these animals, which can cause severe damage to crops planted within or close to existing forest boundaries, and which are therefore regarded as pests. Unfortunately, this species is also threatened by genetic contamination via hybridization with free-ranging domestic and feral animals. Incidences of such hybridizations have been confirmed from Luzon and Mindanao, and reported from Basilan and other islands.

Bibliography. Cruzana et al. (2005), Griffin & Griffin (2000), Groves (1997, 2001a, 2001b), Heaney, Balete, Dolar et al. (1998), Heaney, Balete, Gee et al. (2005), Heaney, Tabaranza et al. (2006), Oliver (1992, 1995), Oliver, Cox & Groves (1993), Rabor (1977), Wu Guisheng et al. (2006).

Figures

On following pages 10 Phılıppıne Warty Pıg (Sus phı/ıppensıs) Mındoro Wany Png (Sus olıven) 12 Pılawın Bearded Pıg (Sus ıhoanobırbus). 13 Bearded Psg (Sus barbatus), 14 Sulawesı Wany Pug (Sus celebensıs) 15 Javan Wany Pıg (Sus venucosusl. 16 Eurasıan Wıld Pıg (Sus scrola) 17 Pygmy Hog (Porcııla salvımı)

Subspecies and Distribution. S. p. philippensisNehring, 1886 — LuzonandassociatedIs (Polillo, Catanduanes, and, formerly, Marinduque). S. p. mindanensis Forsyth Major, 1897 — Mindanao and surrounding Is (Samar, Biliran, Leyte, Bohol, Camiguin, Basilan, and associated smallerIs).