Postconflict behavior among female Sichuan snub-nosed monkeys Rhinopithecus roxellana within one-male units in the Qinling Mountains,China

For group-living primates, the information on postconflict management is crucial for understanding primate competition and cooperation. However, such information is poorly known for snub-nosed monkeys, especially for wild populations. In this study, from September 2007 to June 2008, we investigated postconflict behavior among adult females Sichuan snub-nosed monkeys Rhinopithecus roxellana within one-male units in a wild, provisioned group in the Qinling Mountains of China by means of the time-rule method and the PC-MC method. We obtained a total of 81 PC-MC pairs and each individual was involved in only 0.004 aggressive behavior per observation hour. The first affiliative behavior was more likely to occur within the first minute after a conflict. The postconflict affiliative behaviors most often seen were contact-sit, embrace and grooming. The affiliative contacts between adult females occur due to selective attraction, i.e. reconciliation. The pattern of postconflict affiliation demonstrates that the R. roxellana belongs to a tolerant species.

First evidence of prey capture and meat eating by wild Yunnan snub-nosed monkeys Rhinopithecus bieti in Yunnan,China

Most extant nonhuman primates occasionally prey on fast-moving, warm-blooded animals; however, Indriidae, Lepilemuridae, and Colobinae either scavenged for meat or did not eat meat at all. Here we report six cases of animal consumption by the snub-nosed monkey Rhinopithecus bieti in a wild, habituated group between 2004 and 2009 in Yunnan, China. At present, only males in an all-male unit within the study group were involved in active hunting. Such a male-biased activity may be related to the group structure and spatial spread of R. bieti. Two females were observed eating freshly killed birds. The findings confirmed that R. bieti engaged in scavenging and, when hunting, employed a cranio-cervical bite to kill their prey. Meat eating is likely a nutrient maximization feeding strategy in R. bieti, especially in males. A begging behavior occurred after successful prey capture. Although begging was observed, no sharing of the meat was seen. The present findings illuminate the dietary diversity of R. bieti and their ability to expand their dietary spectrum.

Activity budgets in a group of Sichuan snub-nosed monkeys in Shennongjia Nature Reserve,China

We examined time allocation by Sichuan snub-nosed monkeys Rhinopithecus roxellana in the montane, temperate and highly seasonal forests of the Shennongjia Nature Reserve in China, in order to improve our understanding of the ecological and social influences on monkey behavior. We collected data on activity budgets in relation to food availability in a group of monkeys from July 2003 to September 2004 （except February 2004）, using instantaneous scan samples. The monkeys spent 36.21% of daytime moving （ n = 21, 269 records）, 24.39% foraging, 9.33% inactive, 11,7% performing social behaviors, and 18.38% performing other behaviors. There were seasonal and annual variations in the proportions of time devoted to some activities. These variations were largely attributed to seasonal or annual fluctuations in the distribution and quality of food resources. Adult males spent more time moving, searching, and displaying other behaviors, but less time feeding and performing social behaviors than adult females. Adults performed other behaviors more often and moving less often than juveniles. These differences in activity budgets may reflect fundamental differences in reproductive biology, parental investment, and development among the different age/sex classes [ Current Zoology 55 （3） ： 173 - 179, 2009] .

A newly-found pattern of social relationships among adults within one-male units of golden snub-nosed monkeys(Rhinopithecus roxenalla)in the Qinling Mountains,China

Group living provides various advantages to individuals in regards to protection avoidance,intergroup competition,productive success and social information.Stable one-male units(OMUs)consist of relationships between the adult females and the resident male as well as the relationships among adult females.Based on continuous observation of a reproductive group of golden snub-nosed monkeys(Rhinopithecus roxellana)in the Qinling Mountains,we analyzed the relationships among adult individual dyads within 4 OMUs.The results indicated that in golden snub-nosed monkey societies,females not only had no strong tendency to build a relationship with the resident male in the OMU but also had no strong tendency to build relationships with other females in the OMU.In comparison with hamadryas(Papio hamadryas)and gelada baboons(Theropithecus gelada),the relationships within golden snub-nosed monkeys OMUs showed neither the star-shaped pattern observed in hamadryas baboons nor the net-shaped pattern observed in gelada baboons.We concluded that the relationships within golden snub-nosed monkey OMUs indicated a third pattern in nonhuman primate societies.Future research is required to determine the potential mechanisms for such a pattern.

A short note on extractive foraging behavior in gray snub-nosed monkeys

Extractive foraging(EF)involves the exploitation of hidden or embedded foods,generally any food that is not visible to the naked eye.Therefore,EF is particularly important for survival in marginal habitats as it provides seasonal fallback foods in low food availability seasons.Although many studies consider primates’EF behavior and category,colobine species are usually categorized as non-extractive foragers and few studies quantitatively examine their EF behavior.In this study,we examined the EF behavior of one colobine species,the gray snub-nosed monkey(Rhinopithecus brelichi),at Yangaoping in Fanjingshan National Nature Reserve,Guizhou.We recorded 6 categories of EF behaviors.The most frequently sought-out foods were seeds,young bamboo and invertebrates.Extracted foods accounted for an average of 26.02%of feeding records.As the monkey engages in little EF behavior in the winter when the food availability is low,these results seem to do not support the hypothesis that EF serves to secure additional resources during lean times in marginal or seasonal habitats.According to these findings,we suggest R.brelich should be considered as an extractive forager.Our study also highlights the need for increased representation of colobines in the EF literature to better inform the discussion concerning its link to primate brain evolution.

Spatial pattern in the foraging group of Sichuan golden monkeys

One of the major social-biological characteristics in the genus Rhinopithecus is that the animals live in large groups of tens to hundreds of individuals. Study of the distribution pattern of various age-sex classes in the foraging Sichuan golden monkey troop has revealed that the spatial pattern of the Sichuan golden monkey group is an ellipse with its vertical axes longer than the horizontal axes. Most members are concentrated in the center and the center-back.Adult males gather in the front, the center and the back of the troop; adult females and the young assemble in the center and near-center; sub-adult males are mainly distributed in the center-back and back, but some are also seen in the front, front-center and center; sub-adult females are more or less uniformly dispersed. The spatial distribution of various age-sex classes seems well correspondent with their status and role in the group. This result indicates that the spatial distribution strategy adopted by Sichuan golden monkeys is