Chapter 15: Philippine warty pig Sus philippensis (Nehring, 1886)159
consists of pine forest, and where there was no recent informa-
tion on pigs; (2) Bataan, Luzon (23,853 ha), consisting of mon-
soon forest; pigs (and hunting pressure) reported; (3) Quezon,
Luzon (535 ha), with remnant tract of lowland rainforest; pigs
reported in 1978, but no recent information; (4) Mt. Isarog, Luzon
(10,112 ha); wild pigs (and hunting pressure) reported in 1978;
no recent information; (5) Leyte Mts, Leyte (about 42,000 ha),
with mostly montane and semi-evergreen forest, although some
parts are threatened by encroachment; probably still support-
ing a good pig population; (6) Mt. Apo, Mindanao (72,184 ha),
formerly montane and lowland rainforest, but most of the latter
lost to encroachment; wild pigs definitely present; and (8) Mt.
Malindang, Mindanao (50,000 ha), with similar conditions as
Mt. Apo (above). On Bohol Island, where wild pigs are reported
to be close to extinction, the taxonomy of these pigs remains
unresolved according to Oliver (1995).
Little is known about the ecology, behaviour, distribution,
and conservation status of P. philippensis and even its presence
or absence on many islands is uncertain. In terms of its conser-
vation, the best indicator we can currently consider is the extent
of remaining forest where populations of this pig can still occur
(Meijaard et al. 2011).
Descriptive Notes
Philippine warty pigs are mainly black with grey skin and can be
brown on the mane. This mane forms a crown tuft and extends
on the back, in particular in mature males. Adult males have
four warts and gonial hair tufts which are mainly whitish. Adult
females also have gonial tufts, but they are less developed than
in the males. On Luzon, adult males often have tufts of white
hair on the side of the jaw and scattered in the dark hair over
the rest of the body (Heaney et al. 2016). Few cranial samples
are available; however, the facial skeleton appears more elon-
gated than Sus celebensis and Sus scrofa but does not reach the
length of Sus barbatus and Sus verrucosus. The skull is crowned
with the occipital crest elongating backward. This species has
2n = 36 chromosomes, unlike other pig species that have 37–38.
S. p. philippensis differs from S. p. mindanensis in having a grey
crown tuft, larger facial warts and white gonial tufts (yellow in
mindanensis). The latter subspecies differs from philippensis in
having the mane mainly black with fringe absent and a more
rounded skull (Oliver et al. 1993; Meijaard et al. 2011).
Habitat
Late Pleistocene fossils of Philippine warty pig, c.50,000–68,000
years ago, were recovered from an archaeological site in the
Cagayan Valley, along with those of an extinct dwarf buffalo and
Cervus mariannus (Heaney et al. 2016). Also, Philippine warty
pig remains were found at another archaeological site in Cagayan
Valley, dated to about 4000 BP, indicating its importance to
Neolithic people at that time; these warty pig remains were found
along with the remains of the first documented domestic pigs
(S. scrofa) in the Philippines (Heaney et al. 2016), indicating that
some level of hybridization might have occurred for thousands
of years.
As other wild pig species, the Philippine warty pig was widely
distributed in most of the Philippines from sea level up to 2800 m
(Rabor 1977; Heaney et al. 1998, 2005). Today it is primarily
found in the last remote forest at high altitudes (Oliver 1995),
although in a survey along the Sierra Madre range in Luzon,
Duya et al. (2007) saw and were told about the presence of the
species at low-altitude (300 and 400 m) moderately disturbed
limestone forest, secondary lowland forest and selectively
logged lowland forest, as well as higher-altitude (500–1400 m)
logged forest and montane forest. Philippine warty pigs were
not found or reported to occur in mossy forest above 1500 m
(Duya et al. 2007). On the slopes of Mt. Pinatubo they occur
mainly among tall Saccharum (sugar cane) stands and regener-
ating vegetation (Heaney et al. 2016). The species is believed to
be common in some national parks and reserves where undis-
turbed large forest areas still occur. Observations of animals and
signs were found on Mindanao in montane and mossy forest. In
the past some individuals have been reported over 1000 m a.s.l.
in Mindanao, but today there is no information on observations
at these altitudes (Heaney et al. 2006).Movements and Home Range
No studies have been carried out on the movements and home
ranges of this species. Information from the Agta people, tradi-
tional hunters in the Sierra Madre range of Luzon, suggests that
Philippine warty pigs sometimes move in large migrating herds
(Mudar 1997), not unlike the bearded pig Sus barbatus further
west. At other times, these pigs move in small family clusters,
sometimes a mother and her young, or several sisters and their
young. They reportedly do not range widely, over distances of
10 km at best, moving over a fixed territory from the coast to
well up the mountain slopes (Nelson 1998).Activity Patterns
Information on the activity of this species is poor with only a
few observations that report primarily nocturnal activity in
disturbed areas (Meijaard et al. 2011), a behaviour reported in
other pig species under severe hunting pressure.Feeding Ecology
Very little is known about the diet of this species. The scarce
information available comes from montane forests where indi-
viduals presumably feed on tubers, fruits, and invertebrates
(Meijaard et al. 2011).Reproduction and Growth
Information on reproductive behaviour is all but non-existent.
The Philippine warty pig has bred in captivity just once, result-
ing in a litter of five piglets (Meijaard et al. 2011). Heaney et al.
(2016) report that local people on Luzon told them that litter
size in the wild is typically two, which is much smaller than in
domestic pigs.Behaviour
Very little information is available. However, Philippine warty
pigs, similarly to other wild pig species, live in groups consti-
tuted of sows and their piglets with juveniles of different ages..01712:38:21