Behavior, Ecology, and Conservation Biology of Asian Leaf-eating Monkeys

Over 50 percent of Asian leaf-eating monkey taxa are currently under threat. Yet little is known about the behavior and ecology of these primates. This project consists of several studies; all aim to augment our knowledge regarding the animals’ dietary and habitat requirements, social relations, and life histories. Such investigations provide key biological information for developing effective conservation programs and facilitating interspecific comparisons.

Presently, we are focusing on (though not limited to) five species: Sichuan snub-nosed (or golden) monkeys Rhinopithecus roxellana, Yunnan snub-nosed monkeys Rhinopithecus bieti, Tonkin snub-nosed monkeys Rhinopithecus avunculus, red-shanked douc langurs Pygathrix nemaeus, and proboscis monkeys Nasalis larvatus. Studies of Rhinopithecus roxellana include feeding and ranging behaviors, aggression and reconciliation, vocal communication, life history and population dynamics. Group composition, diet, and habitat utilization constitute the main components of Rhinopithecus bieti and Rhinopithecus avunculus investigations. In Pygathrix nemaeus and Nasalis larvatus, we are documenting parental care and infant behavioral development in captivity, as well as collecting data on population size, diet, and locomotor behavior in the wild.

We employ non-invasive methods, commonly adopted by primatologists, that consist of behavioral observation and audio and video recordings. Our investigations provide baseline data about the monkeys that are beneficial to developing ex situ and in situ conservation management schemes. The presence of researchers in the area also enhances the survival of the monkey populations and promotes public awareness.