Visayan warty pig  (Sus cebifrons)

Classified as Critically Endangered (CR - A1cde, B1+2acd, E) on the IUCN Red List 2002 (1).

The Visayan warty pig is a little-known, small, forest-dwelling pig that has only recently been recognised as a separate species (2). The males (boars) are much larger than females (sows) (3) and, uniquely amongst wild pigs, develop crests and manes that are up to 23 cm long during the breeding season (4). Sows have only 3 pairs of nipples, a feature that was previously thought to be unique to the pygmy hog (Sus salvanius) (4).

Historically found throughout the Visayan Islands (the central archipelago of the Philippines), this species is now extinct over at least 98% of its former range, with the few surviving populations confined to fragments of remaining habitat on the islands of Negros and Panay (4). Two subspecies are currently recognised; Sus cebifrons cebifrons from the island of Cebu, which was exterminated in the mid-1990s, and S. c. negrinus from Negros. Neither the Panay animals, nor others from Masbate (assuming this population still survives), have been formally described and may represent additional subspecies (4).

Found in patches of remaining rainforest (2).

Very little is known about the natural ecology of the Visayan warty pig and few behavioural studies have occurred in the wild (4). These pigs are usually found in groups of 4 to 5 individuals although larger groups and solitary males have also been observed (2). Piglets are born in the dry season that runs from January to March; sows produce an unusually small litter of 1 - 3 piglets (3) (4), and these young have a particularly slow growth rate (4).

Visayan warty pigs feed on a wide variety of forest fruits, roots and tubers, but will also emerge from the forest to plunder cultivated vegetable and cereal crops (6).

The Visayan warty pig is highly endangered; the species has been lost from 3 of the 6 major islands where it was found, and is on the verge of disappearing from a fourth (4). Deforestation in the Philippines has been widespread and habitat loss along with hunting pressure is one of the main causes of the precipitous decline in numbers. Interbreeding with domestic pigs provides a further threat to the few surviving populations and it seems unlikely that purebred forms will persist in the wild for long (4). These pigs also suffer from persecution by local farmers who view the animals as pests; they are subject to high levels of illegal hunting pressure for local consumption, are caught in pitfall traps or wire snares, and may sometimes be killed with explosive devices that are baited and buried in the ground, to be excavated by rooting individuals (6).

The Visayan Warty Pig Conservation Programme was established in 1991 (4), with the long-term aim of reintroducing 'warties' into areas from which they have been lost (3). Two captive breeding and rescue centres have been established on Negros, one by Silliman University and another at the Negros Forests and Ecological Foundation (4). In addition, a centre has been established on the island of Panay by the College of Agriculture and Forestry; as of June 2001, the total captive population for the species was 41 (4). The Visayan Warty Pig Conservation Programme is also involved with research into these poorly understood pigs and works to increase local awareness of the issues involved. The Philippines has more species of wild pig than any other nation, however, most of these are severely endangered, and habitat loss and hunting are rife; the efforts to save the Visayan warty pig are a battle against time (3).

View information on this species at the UNEP World Conservation Monitoring Centre.

For more information on the Visayan warty pig see:

• Oliver, W.L.R. (ed.) (1993) Pigs, Peccaries and Hippos: Status Survey and Conservation Action Plan. IUCN, Gland, Switzerland. Available at:
  http://data.iucn.org/dbtw-wpd/edocs/1993-055.pdf
• Groves, C.P. (1997) Taxonomy of wild pigs (Sus) of the Philippines. Zool. J. Linn. Soc., 120: 163-191
• Oliver, W.L.R. (1995) The taxonomy, distribution and status of Philippine wild pigs. In: Proc. 2nd International Symposium on Wild Boar and Sub-order Suiformes. Ibex, J. Mountain Ecology, No3: 26-32.