Social organization of the babirusa (Babyrousa babyrussa) and their use of salt licks in Sulawesi, Indonesia

The babirusa (Babyrousa babyrussa), an endangered suid endemic to Sulawesi, Indonesia, has scarcely been studied in the wild. Sixty hours of observation on social organization of babirusa and patterns of visitation to a natural salt lick were made during 32 months in 1989-1994. Babirusa groups observed at the lick were 1-13 individuals (n = 393 groups), and solitary adult males or matriarchal groups were the most frequently sighted group types. A daily pattern of visits to the lick was discernible with the highest number of groups at the lick between 1700-1800 h. Mean duration of visit was greatest (17.4 min) between 1700-1800 h. Use of the lick differed markedly among mammalian species; 98.0% of all activity was of babirusa compared with <1.0% by each of three other endemic Sulawesi mammals. Chemical analysis of soil and water at the lick revealed higher levels of minerals than in control samples. Possible reasons for geophagy by babirusa are discussed.