Arboreal locomotion in wild black-and-white snub-nosed monkeys (Rhinopithecus bieti)

This paper presents spatiotemporal gait parameters of arboreal locomotion in the colobine Rhinopithecus bieti in its natural habitat. While adult females used exclusively either extended-elbow vertical climbing or pulse climbing, the much larger adult males preferred the less demanding flexed-elbow vertical climbing on thin trees or on trunks with handholds. If sex-specific differences are taken into consideration, the differences between flexed-elbow and extended-elbow vertical climbing in Rhinopithecus parallel those observed in Ateles. During flexed-elbow vertical climbing, the gait parameters of R. bieti are very similar to those of spider monkeys (Ateles fusciceps) or bonobos (Pan paniscus). Maximum limb joint excursions also lie in the range of hominoids and atelines and are clearly larger than in Macaca fuscata. It seems likely that climbing kinematics may differ more between Rhinopithecus and macaques than between Rhinopithecus and hominoids or atelines.