Nest Building Behaviour of Sulawesi Babirusa (<i>Babyrousa celebensis</i>)

Abstract

A total of 504 observations of nest building behaviour and the re-use of sleeping nests exhibited by 10 individuals of Sulawesi babirusa (Babyrousa celebensis) were made in spacious outdoor enclosures on Bali, Indonesia. We recorded behavioural characteristics associated with the timing of nest building behaviour, nest sites, and selection of nestbuilding materials. Both sexes frequently participated in the construction of sleeping nests during the short period from 17:00 hr to 18:00 hr, which corresponded to the period between the evening feed and the time of sunset. Young babirusa contributed from the age of 15 weeks. The babirusa favoured specific nesting sites in the enclosures determined by available structural supports such as walls, trees or corners. Various kinds of plant materials available in the enclosure were used. In addition to picking up fallen plant matters, they also pulled various parts off trees while standing on the hind limbs. In one instance, parts of a wooden fence were used due to the lack of other nesting materials. When housed as a group, consistent leadership of the nesting behaviour was not recognised; they seemed to prefer cooperative behaviour and built a communal nest. We concluded that nest building behaviour, for resting and sleeping, was a normal and important behaviour of the babirusa and that the provision of nest building materials to captive babirusa was an effective form of enrichment.

Effects of Meteorological Factors on the Expression of Nesting Behaviour in the Sulawesi Babirusa (<i>Babyrousa celebensis</i>)

“…The data set was divided into two groups, the 'expression group' and the 'non-expression group' depending on whether or not the nesting behaviour was exhibited by at least one individual each day. Based on 1) our previous findings that the animals most frequently exhibited nesting behaviour for one hour from 17:00 hr to 18:00 hr [11], 2) the availability of wind data that were measured at every hour, and 3) the physiological aspect that existed, but with the unknown time difference/interval (Δt) between "the exposure to external stimuli" and "the expression of the nesting behaviour that we can observe" , we (Table 1) who experienced all seasons for more than 12 months in total (368 days of the three dry seasons and 332 days of the three rainy seasons).…”

“…The study was conducted at Babirusa Park [11,12], located in a rice-growing area at an altitude of 144 m, Lodtunduh village, Bali, Indonesia. The study period was 1936 days long from 01 st January 2005 to 20 th April 2010.…”

“…Two pairs of adult Sulawesi babirusa and their six infants (Table 1) kept in the two adjacent spacious outdoor enclosures with their pens (Fig. 3) were observed [11]. Generally, one enclosure accommodated one breeding pair and their infant, and they had ad libitum access to the entire area including the pen, grass field, swimming pool and wallowing mud.…”

“…A detailed description of the methods used in this study has been noted by Ito et al (2019) [11]. A total of 12 staff including two authors took turns participating in the data collection.…”

“…In the preceding article [11], we described several characteristics of the nesting behaviour of this species, observed in a spacious outdoor enclosure fulfilling the environmental requirements [12,13], in Bali, Indonesia. In short; 1) Mainly before dusk, but not every day, both sexes of babirusa gather plant matters such as fallen leaves, twigs, grass (Figs.…”