The ecology and behavior of the four species of Rhinopithecus, snub-nosed monkeys, are rapidly becoming well known. New field studies reveal in depth the striking adaptations of these colobines. Diets range from those typical for tropical colobines to diets dominated by lichens. The monkeys form bands, at times consisting of more than 400 individuals; these bands are based on the one-male, multi-female units common in colobines. We review the diet, range use, and social organization of snub-nosed monkeys, and then explore the power of socioecological theory to explain their multilevel social organization.Snub-nosed monkeys represent an ecological array, from the Tonkin snub-nosed monkeys (Rhinopithecus avunculus) of tropical forests in Vietnam to the black snub-nosed monkeys (Rhinopithecus bieti) of temperate conifer forests in China. The step-wise gradation of environments provides for a step-wise gradation of behaviors, making this array particularly informative. Further, the harsh environments of black snub-nosed monkeys and golden snub-nosed monkeys (Rhinopithecus roxellana), in which snows are common in winter, put their adaptations in stark relief. Snub-nosed monkeys are useful in understanding the behavioral flexibility of primates, as well as in investigating the influence of environment on both feeding ecology and social organization.

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.

There are few data on the daily ranging distances of Yunnan snub-nosed monkeys (Rhinopithecus bieti). We fitted 1 adult male from a natural group at Jinsichang in China's Yunnan Province with a global positioning system (GPS) collar and tracked him from December 2003 to October 2004 to estimate the daily ranging distances of the group. The total acquisition rate of the GPS collar was 82.2%, which indicates that one can use GPS collars to track the species efficiently in high-altitude, temperate, coniferous forest. We obtained group locations or fixes at 5 predetermined times during the day. The sleeping sites of the subjects are the key points to estimate the day range. We compared 2 measures of day range: the 2-point straight-line displacement and the multipoint cumulative daily ranging distance. Straight-line displacement between 2 consecutive mornings or 2 consecutive evenings can substitute for that between the morning sleeping site and the evening sleeping site. In general, the group does not move at night. The 2 measures of day range yielded different results. The multipoint cumulative daily ranging distance was the method of choice to measure their daily travel costs. The minimum required Int J Primatol (number of fixes per day was 3. Per statistical evidence, the number of full-day group follows per month influences the estimate of day range of the group and ≥10 d is required to obtain a reliable estimate; 5 d per month might not be enough. We dealt mainly with the methodologic aspects of day range calculations. We did not address functional aspects on the estimate of day range, viz. the influence of vegetation, food distribution patterns, climate change, seasonality, and the monkey group itself.

Black-and-white snub-nosed monkeys (Rhinopithecus bieti) have almost never been the subject of any behavioural observations in captivity. This study was aimed at providing preliminary information about agonistic and reconciliation behaviour in a group kept at the Kunming Institute of Zoology in China. Established procedures were used for this investigation (i.e., the postconflict/matched-control method and the time-rule method). Intra-group aggression rates were quite low. Postconflict affiliation as well as selective attraction of former opponents to each other following conflicts was demonstrated. Former opponents contacted each other earlier in postconflict periods than in matched-control periods. The average conciliatory tendency of all focal individuals combined was 54.5%. After an agonistic interaction, the first affiliative contact between former aggressors usually took place within the first minute. The behaviours most often shown as first affiliations after a conflict were body contact, mount, touch, and "hold-lumbar", of which the latter is an explicit reconciliatory gesture. Furthermore, the adult male intervened non-aggressively in 84% of all conflicts (n=25) among the adult females. Overall, the patterns of aggression and reconciliation observed in R. bieti bear many of the traits that characterise tolerant primate species.