GROUP-STRUCTURE AND BEHAVIOR OF BABIRUSA (BABYROUSA-BABYRUSSA) IN NORTHERN SULAWESI

Studies were carried out at two 'salt-licks' in lowland tropical fores t on North Sulawesi, Indonesia. During 60 days of observation 586 sigh tings of babirusa were made, comprising 161 adult males, 155 adult fem ales, 11 adults of unknown sex, 78 subadult males, 53 subadult females and 34 subadults of indeterminate sex; juveniles were observed 94 tim es, 19 males, 12 females and 63 of unknown sex. We saw 226 groups rang ing in size from one to eight animals (median = 2). Almost half the si ghtings were of solitary animals, usually adult males. Bachelor groups of four or more babirusa were never seen. Adult females were rarely s een without company, often both juveniles and subadults being sighted together with them. There were never more than three adult females in a group. There were about twice as many family groups without adult ma les as there were with males. Agonistic behaviour between males was co nfined to 'threat at a distance', 'nose in the air', 'head under jaw s ubmission' and 'front half supported' behaviours. Incidents of female- female agonistic behaviour were fewer, but in two, the dominant female chased her inferior off the 'salt-lick'.