Preliminary Study of the Newly Discovered Primate Species Rhinopithecus strykeri at Pianma, Yunnan, China Using Infrared Camera Traps

Abstract

The Burmese snub-nosed monkey (Rhinopithecus strykeri) is one of the most recently discovered primate species, and occurs only along the border of Myanmar and China. Its ecology is largely unknown owing to its harsh and remote habitat. However, study of this new species can contribute to our understanding of how primates adapt to a high-altitude lifestyle. We here describe our preliminary study of a group of R. strykeri, using a mix of direct observation and camera traps, at Pianma, Yunnan, China. From May 2013 to May 2014, we conducted direct observation and deployed 30 camera traps to examine the social characteristics of R. strykeri, estimate group home range via the modified minimum convex polygon method, and estimate the vertical range used. We achieved direct observation on 8 days and obtained 222 camera trap images triggered by the passing of R. strykeri. The cameras captured five one-male, multifemale units and one all-male unit. We observed fusion of units without aggression during both direct observation and camera trapping, suggesting that R. strykeri lives in a multilevel society, similarly to the other members of the genus. The ratio of adults to immatures was high relative to stable populations of Rhinopithecus, suggesting the population is in decline. We estimated the group’s home range to be 22.9 km2 and found that R. strykeri occurred at 2400–3300 m. Our work shows that camera traps can be used effectively to survey rare primates.