Chapter 14: Visayan warty pig Sus cebifrons (Heude, 1888)151
Figure 14.1 Visayan warty pig distribution (source: IUCN 2008, Red List of Threatened Species). (A simplified black and white version of this figure will appear in some
formats. For the colour version, please refer to the plate section.)Taxonomy
The Visayan warty pig S. cebifrons was originally described from
Cebu Island on the basis of only one skull, but only in 1993 it
was recognized as a full species. Initially considered a subspecies
of S. philippensis (Groves 1997), two phylogenetic studies sug-
gest that S. cebifrons is a taxon very different from S. philippensis
(Groves 1997; De Leon et al. 2008). This new species could be
the most archaic member of the Sus genus. As S. cebifrons seems
to be a sister species to all other members of the genus Sus, it is
possible that this species became separated from the other taxa
early in the evolution of this genus, probably in the Pliocene.
The frequent glacial–interglacial cycles during this period and
concomitant sea level falls and rises may have facilitated the dis-
persal of the ancestors of these species through bridges between
islands, after which they became isolated, following their own
unique evolutionary paths.
Presently, two subspecies are recognized in Visayan warty
pig (Groves 1997). The nominal form from Cebu has become
extinct, but the other subspecies, S. c. negrinus, still occurs on
Negros Island. Recent genetic studies describe the possibil-
ity of a third subspecies but this assumption is based only on
one specimen from Panay Island and needs further genetic
evidence (Oliver 2004, 2008). However, animals in zoos from
the two islands (Panay animals are in the USA, Negros animals
in Europe) seem to look consistently different; for example,
Panay animals seem to have a more pronounced colour differ-
ence between the flanks and the more backward-reaching mane
(R. Wirth, personal communication and also see below).Subspecies and Distribution
This species has been eradicated from most of its native range
of the Visayan Islands in the central region of the Philippines
(Figure 14.1). Currently it occurs in the West Visayan Islands
(Negros and Panay islands). On the Cebu, Guimaras, and Ticao
Islands the species is thought to be extinct, although it occurred
on Cebu at least until the 1960s (Groves & Grubb 1993; Oliver
1995; Oliver 2008). This species was recorded on the island of
Masbate until 1993, but no new records of the species exist and
it is likely extinct on the island (Groves & Grubb 1993; Oliver
2008). In other large Philippines islands such as in Bohol, this
species is replaced by the Philippine warty pig (S. philippensis)
and in Mindoro by the Mindoro warty pig (Sus oliveri).Descriptive Notes
Body measurements for both sexes: Shoulder height: 30–63 cm.
Head and body length: 90–125 cm. Tail length: 23 cm. Body mass:
20–80 kg..01612:38:23