Social Behaviour of Proboscis Monkey (Nasalis larvatus) in Taman Safari Indonesia, Cisarua, Bogor

Abstract

Proboscis Monkey (Nasalis larvatus) is a primate species that live in group, it occurred social interaction within group. In general, the form of social interaction among individuals include grooming activity, agonistic, play, and sexual. This research addressed to determine social behaviour of proboscis monkey. The objects of this study were six Nasalis larvatus with different ages and sexes. Social behaviour observation was carried out using focal animal method. Determination of the hierarchy in adult females based on grooming, agonistic, and sexual activities. The observation began at 09.00 a.m until 04.00 p.m for 492 hours. Adult females showed the greatest percentage on doing autogrooming and grooming to others than adult male and infants. Adult female with high rank showed less percentage (76,39%) on doing grooming than other adult females (78,00%). Male performed open mouth threat, showed canine, gave vocalization, and chasing the sounds. Females only performed open mouth threat and gave vocalization. Most adult female with high rank was done agonistic activity against other individuals (23,61%). Playing activities were done by the infants of proboscis monkey. Sexual behaviour only occurred between the adult male and female proboscis monkeys.