Ploughing behaviour of the babirusa (Babyrousa babyrussa) suggests a scent marking function

Abstract

A unique form of behaviour, 'ploughing behaviour', was studied in experiments carried out on 13 babirusa, three adult males, two sub-adult males, five adult females and three sub-adult females. Ploughingbehaviour was observed when individual animals were introduced singly into empty sand-filled enclosures at Antwerp Zoo. The animal put its snout into the sand to such a depth that the sand was just in front of its eyes, whereupon it knelt forward onto its chest. The head and chest of the animal were thereby pushed forward through the sand and canted left and right alternatively. Ploughing behaviour was almost exclusively 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 at the sides of the mouth proir to ploughing had disappeared by the end of this activity. This supports the idea that ploughing by the babirusa has a scent-marking function. The adult female did not show ploughing behaviour.