Chapter 6: Sulawesi babirusa Babyrousa celebensis (Deninger, 1909)61
on higher and less-accessible ground. There the tree cover is pre-
dominantly tropical lowland evergreen and semi-evergreen rain-
forest. These are not dominated by any particular family of trees
(Whitmore et al. 1989; Whitten et al. 2002). Palms are common
in the lowland forest, including Oncosperma horridum, Liculala
celebensis, Pinanga, Areca, Caryota, and Livistona rotundifolia
(Whitten et al. 2002). Ebonies (Diospyros spp.) were also com-
mon in dense clumps. The dipterocarps included Anisoptera cos-
tata, Hopea celebica, H. gregaria, Shorea assamica, Vatica rassak,
and V. flavovirens. Many different kinds of fruit-bearing trees
are distributed throughout these forests. Although the detailed
nature of the babirusa’s association with these various species of
food-bearing plants has not yet been studied, those reports that
have been published were gathered together and analysed by Leus
(1994, 1996). They included Ficus spp., Canarium sp., Elatostema
sp., Lithocarpus sp., Mangifera sp., and Pangium edule.
Movements and Home Range
Territorial Range
Very little is known about the territorial ranges used by babirusa
in the wild. Nothing has yet been reported to indicate how far
babirusa will normally travel, but fragments of information sug-
gest that it is quite restricted. Because it was impossible to dif-
ferentiate between the females entering the salt-lick study sites,
it was not possible to say whether these females had remained in
the same locality or had a wide range that overlapped with those
of other females (Patry et al. 1995; Clayton & MacDonald 1999).
However, because the males could be identified from one another
by the shape and size of their canine teeth (Figure 6.2A), the
observations suggest that the adult male babirusa do have home
ranges, and that these overlap at the salt-lick with those of a num-
ber of other adult males. It is possible, therefore, that home ranges
may not be large where they permit sufficient access to food and
water, salt-lick components, and members of the opposite sex.
There is evidence that babirusa on Sulawesi can swim rela-
tively large distances: a single adult male babirusa was reported
approximately 500 m from the shore of Lake Poso in Sulawesi,
across which it appeared to be swimming (Melisch 1994). This
observation substantiates claims frequently repeated in the
older literature. Recent experience of babirusa in several zoo-
logical gardens reinforces the understanding that babirusa
derive benefit from lying in and swimming through water.
The skeletal and muscular anatomy of the babirusa that ena-
bles terrestrial and aquatic locomotion has been reviewed andFigure 6.3 Sulawesi babirusa distribution (Source: IUCN 2016, 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.)
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