PLOWING BEHAVIOR OF BABYROUSA-BABYRUSSA (SUIDAE, MAMMALIA) SUGGESTS ASCENT-MARKING FUNCTION

A unique form of behaviour, 'ploughing behaviour', was studied in expe riments carried out on 13 babirusa, three adult males, two sub-adult m ales, five adult females and three sub-adult females. Ploughing behavi our was observed when individual animals were introduced singly into e mpty sand-filled enclosures at Antwerp Zoo. The animal put its snout i nto the sand to such a depth that the sand was just in front of its ey es, whereupon it knelt and slid forward on to its chest. The head and chest of the animal were thereby pushed forward through the sand and c anted left and right alternately. Ploughing behaviour was almost exclu sively performed by adult males, the periods of longest duration being seen either in the enclosure of another male or in a freshly cleaned enclosure. The copious amounts of saliva which were produced as foam a t the sides of the mouth prior to ploughing had disappeared by the end of this activity. This supports the idea that ploughing by the babiru sa has a scent-marking function. The adult female did not show ploughi ng behaviour.