Proboscis Monkeys: from Ecology to Social System

Abstract

Proboscis monkeys (Nasalis larvatus) belong to the colobines and are a large, sexually dimorphic and primarily arboreal species. These monkeys are endemic to Borneo Island, inhabiting areas by rivers in mangroves, peat swamps or riverine forests, and their typical social unit is a one-male group consisting of an adult male and several adult females with their offspring. Since some of their favorite habitats are swampy, observation and tracking of the monkeys in inland forests is difficult, and hence, knowledge about the ecology and the social system of proboscis monkeys is incomplete. However, by a lot of efforts of researchers, our knowledge of the monkeys has greatly expanded in these days. In this paper, I highlighted novel findings on proboscis monkey ecology and social system, comparing to those in other colobine species.