Chapter 7: Moluccan babirusa Babyrousa babyrussa (Linnaeus, 1758)71
Figure 7.1 Moluccan babirusa 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
Babyrousa babyrussa, known as the Moluccan babirusa, is
one of the four species of babirusa in Sulawesi and adjacent
islands (Meijaard & Groves 2002), namely B. celebensis of north
to north-east, central, and east Sulawesi, B. togeanensis of the
Togean Islands, and B. babyrussa of the Sula Archipelago and
Buru (Moluccas), with B. bolabatuensis occurring as a now-
extinct form (one fossil and one recent) in south and south-west
Sulawesi.
Babirusa is the only genus of the subfamily Babirousinae in
the Suidae (Oliver 1995). Although babirusa shares the same
number of 38 diploid chromosomes with Sus species, there
are differences across five pairs of chromosomes (Bosma & de
Hann 1981; Bosma et al. 1991). DNA analysis by Gui-Sheng
et al. (2006) showed that babirusa should have been classified
as an independent family, based on both genetic and morpho-
logical characters, such as the larger stomach and remarkable
canine teeth in males.
The Moluccan babirusa was previously considered as a
subspecies of B. babyrussa, i.e. B. b. babyrussa (Groves 1980).
However, along with other two subspecies, B. b. babyrussa was
upgraded to full species status, B. babyrussa, because of its spe-
cific morphological characters (Meijaard & Groves 2002).
Subspecies and Distribution
The Moluccan babirusa occurs on two of the Sula Islands
(Mangole and Taliabu) and on Buru Island (Macdonald 1993;
Davidson et al. 1995) (Figure 7.1) in the Moluccan region, east
of Sulawesi. Buru, Taliabu, and Mangole cover an area of about
8473.2 km^2 , 1469.93 km^2 , and 12717.60 km^2 , respectively.
The Moluccan babirusa is endemic to the islands where it
occurs, but it remains unclear how the species arrived in this
region. Babirusa might have swum or rafted from Sulawesi
to the islands where it now occurs, possibly island-hopping
through the Banggai Archipelago, then to Taliabu, Mangole, and
Sulabesi, and finally to Buru. The ability of babirusa to swim had
been observed in Lake Poso (Melisch 1994; Akbar et al. 2007).
Babirusa does not currently exist in Peleng, an essential step-
ping stone from Sulawesi to the Sula and Buru groups, but may
have occurred there in the past. Swimming or rafting directly to
Sula and Buru islands could be unlikely for a forest species not
adapted to significant expanses of sea environment, although
they have been encountered at sea far from land (Meijaard
et al. 2016). If not dispersed through swimming, it is possible that
vicariance biogeography played a role, although detailed palaeo -
geographical research would be needed (Stelbrink et al. 2012).
A third option is that the Moluccan babirusa was introduced.00912:33:27