Behavior and Biology of Asian Leaf-eating Monkeys

San Diego Zoo Conservation Research is taking a leadership role in the conservation of Asian leaf-eating monkeys. Little is known about the behavior and ecology of these primates; knowledge about the natural history of these animals is fundamental to designing effective, long-term conservation programs.

This project focuses on Asian leaf-eating monkeys, specifically those in the “odd-nosed” group: snub-nosed monkeys, douc langurs, and proboscis monkeys. They are seriously threatened by habitat destruction and poaching, and many have small populations in isolated pockets ranging from temperate broadleaf deciduous/coniferous forests, to subtropical monsoon forests, to tropical riverine and mangrove forests. Compared to other primates, the odd-nosed monkeys have received little attention and knowledge about their biology, ecology, and behavior is profoundly lacking.

We are adopting a broad-based, multi-disciplinary approach to gain insights into the monkeys’ biology, social structures, and population dynamics. We aim to safeguard these species and their diverse habitats by engaging in in- and ex-situ conservation activities that reduce human-monkey conflicts.

In China, we are focusing on features of the social system and vocal communication of Yunnan and Guizhou snub-nosed monkeys. We are also examining ecological and anthropogenic factors that influence the monkeys’ behaviors. Our methods involve behavioral sampling of the monkeys (via direct observations and video- and audio-recordings), vegetation sampling, interviews with local human inhabitants, and participatory mapping.

Additionally, we employ remote sensing and camera traps to examine large-scale habitat use by humans and monkeys. In Vietnam, we are concentrating on Tonkin snub-nosed monkeys, including forest protection and expansion, patrolling, research, and community outreach.  We also are focusing on red- and black-shanked doucs and working with our partners on behavioral studies and anti-poaching efforts in central and southern Vietnam. Finally, we are examining proboscis monkey group structure in relation to environmental conditions in Sabah, Malaysia.