Group Size and Composition of Black-and-White Snub-nosed Monkey (Rhinopithecus bieti) Estimated by Faecesof Sleeping Sites at Baima Snow Mountain

This study was designed to introduce a new method of estimating group size and composition of black-andwhite snub-nosed monkeys （Rhinopithecus bieti ） on the basis of faecal amount at sleeping sites at Mt. Baima Nature Reserve. The monkeys spend nights in the form of one-male, multi-female units （OMUs） and all-male units （AMU）, and their faecal pellets can be classified into three categories： adult males （the largest）, adult females （moderate） and immatures （the smallest） based on their size. Total pellets were counted under sleeping trees used for two nights at Nanren village （99°04′E, 28°34′N, northwest of Yunnan Province, China） in each of four seasons in 2000- 2001. Moreover, data on group composition were collected when the monkeys were passing through an open gully in November 2001. Since the number of adults in OMUs shows a positive significant correlation with the amount of pellets amount in each season, the mean number of feces produced per night per individual is the slope of the regression lines. Thus, group size and composition can be relatively reliably and accurately estimated by the faeces under trees compared with the previous methods of estimation, including the use of monkeys＇ activities and tracks such as broken branches on steep slopes, in deep gorges and under lower visibility. The use of pellets for population estimates displayed 9.4% deviation in regards to population size of adult females. Some causes of the bias were also discussed. The method might be applicable to other monkey groups of this species if their habitats and main foods are similar to those of the study group.

Altitudinal Range of Black-and-white Snub-nosed Monkeys (Rhinopithecus bieti ) at Baima Snow Mountain, China

Faeces were counted along horizontal, 5.0m wide strips at altitude intervals of 100m to examine the altitudinal ranging pattern of a band of black-and-white snub-nosed monkeys （Rhinopithecus bieti） at Nanren （99°04′E, 28°34′N, Baima Snow Mountain Nature Reverse, Yunnan, China） at four areas in each season between 2000-2001. Faeces were also counted along vertical, 2.5 m wide strips in one subvalley and on one subridge in each area. Monkeys used an altitudinal range of 3500-4300m, but preferred occupying the upper forest belt between 3900 and 4200m asl year-round, being at the highest altitude in summer, the lowest altitude in spring, and middle altitudes between autumn and winter （lower in winter than autumn）. Moreover, there were secondary peaks of lower altitude use （3700m） in spring and winter. In addition, more faeces were distributed in subvalleys than on subridges in winter, this suggests that monkeys tend to spend more time in subvalleys where there is less wind and fluctuating temperatures. The significant correlation between faecal density and lichen load might indicate that altitudinal distribution of food resources may act as an important factor affecting the monkeys＇ range. The monkeys might migrate to lower altitudes to eat young sprouts and leaves in spring, and to shelter from snowstorms in winter, possibly resulting in the secondary peaks at lower altitudes.

Positive influence of traditional culture and socioeconomic activity on conservation: A case study from the black-and-white snub-nosed monkey (Rhinopithecus bieti) in Tibet

Found in the Trans-Himalayas of north-west Yunnan and south-east Tibet, the black-and-white snub-nosed monkey （Rhinopithecus bieti） is one of the world’s most endangered primates. A recent survey indicates that only 15 groups with 2500 individuals remain in the wild. However, the Tibetan Xiaochangdu group may be the only equilibrium group in the field since the last investigation in 1988. To evaluate the effects of traditional culture and socioeconomic activity on biodiversity conservation of R. bieti, we conducted a case study in the Honglaxueshan National Nature Reserve in southeast Tibet from June 2003 to May 2005. Interviews, direct observations, and analysis of socioeconomic data indicated major advantages to the conservation of R. bieti, which included that： 1） traditional culture mainly depended on raising livestock and collecting non-timber products rather than forest planting of Tibetan highland barley; 2） religious beliefs, against to kill any wildlife living on the sacred mountain, were mainly influenced by Tibetan Buddhism; and 3） bigger household numbers were induced by the polyandrous marriage system, which resulted in lower per capita resource consumption than smaller ones.

Activity budget of Rhinopithecus bieti at Tibet:Effects of day length,temperature and food availability

How animals allocate their time to various activities has significant consequences for their survival because they reflect the different constraints on time-energy balances. Many ecological variables, such as day length, temperature, food availabil- ity, are supposed to effect on activity budgets allocation of temperate primates. To examine the potential influence of these three variables, the activity budgets ofRhinopithecus bieti was studied at Xiaochangdu, Tibet from June 2003 to March 2005. Pearson correlations were utilized to assess potential relationships between activity budget and day length, food availability and temperature, and stepwise multiple regressions to identify the priority of resting and other activities （activities besides feeding, moving and resting）. Time spent resting and doing ＂other activities＂ is positively related to day length, temperature and food availability. No significant correlations were found between feeding/moving time and any of these variables. This suggests that foraging time （feeding ＋ moving） takes priority over rest and other activities. Day length and foraging time （as independent variables） were related to the time spent in the other two activities besides feeding/moving （as dependent variables）. Both time spent resting and in ＂other activities＂ were highly significant positive functions of day length, with the latter a highly significant negative function of feeding time and moving time. Resting time may therefore be interpreted as taking priority over ＂other activities＂ time. These results provide further evidence of the importance of day length, temperature and food availability to seasonal activity budgets [Current Zoology 56 （6）： 650q559, 2010].

Leaf choice in black-and-white snub-nosed monkeys Rhinopithecus bieti is related to the physical and chemical properties of leaves

To understand the effects of the chemical and physical properties of plant leaves on food choice in Rhinopithecus bieti, we collected mature leaves of nine food and five non-food plant species at the southernmost part of the species＇s range. Chemical properties such as fat, ash, crude protein （CP）, total phenolics （TP）, and fiber content including neutral detergent fiber （NDF）, acid detergent fiber （ADF）, lignin, celluloses and hemicelluloses, and physical toughness were measured. R. bieti tended to choose leaves with lower fiber content, higher ash, a higher ratio of CP/ADF, and lower toughness. No difference was found for fat, crude protein, total phenolics, hemicelluloses and lignin between food and non-food leaves. Even though the ratio of CP/ADF is generally regarded as a good indicator for colobine food choice, the difference in the ratio of CP/ADF between food and non-food leaves was only the result of differences in ADE Since positive correlations were found between ADF and tough- ness from all leaves （both food and non-food species）, and toughness of leaves was likely easier for R. bieti to sense than fiber content via mastication, the toughness of leaves may function as a predictor of food choice in this species [Current Zoology 56 （6） 643-49, 2010].

Terrestrial behavior and use of forest strata in a group of black-and-white snub-nosed monkeys Rhinopithecus bieti at Xiaochangdu,Tibet

Food distribution and predation pressure are considered to be the main ecological factors that influence the use of forest strata （basically arboreality vs. terrestriality） in non-human primates. Here, we investigate ground use of wild, unprovisioned black-and-white snub-nosed monkeys Rhinopithecus bieti by means of the scan sampling method. The results show that the monkeys spent 15.0% of the day time on the ground; 16.6%, 12.7%, and 15.6% for adult males, adult females and juveniles, respectively. Adult males and juveniles of both sexes showed significantly higher rates of terrestrial time than adult females. Females without clinging infants spent significantly more time on the ground than expected, while females with clinging infants spent significantly less time on the ground than expected. These results suggest that the higher degree of terrestrial behavior for males and juveniles may be due to their higher agility in comparison with females. Our study showed that the monkeys fed more on lichens relative to other food items when in the trees, but more on buds/leaves, flowers, fruits/nuts, resin/bark, and herbs when on the ground. According to our investigation, the ecological significance of the species＇ terrestriality lies mainly in the utilization of terrestrial food resources [ Current Zoology 55 （3） ： 180 - 187, 2009].

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.

Birth seasonality and pattern in black-and-white snub-nosed monkeys （Rhinopithecus bieti） at Mt. Lasha, Yunnan

Seasonal variation in environmental factors is vital to the regulation of seasonal reproduction in primates. Consequently, long-term systematic data is necessary to clarify the birth seasonality and pattern of primates in highly seasonal environments. This study indicated that black-and-white snub-nosed monkeys （Rhinopithecus bieti） at Mt. Lasha exhibited strict birth seasonality with a pulse model. Infants were born with a certain degree of synchronization. Birth distribution showed three birth peaks, and the birth pattern showed a ＂V＂ style in even-numbered years and a gradual increase in odd-numbered years. The beginning date, end date and median birth date were earlier in even-numbered years than those in odd-numbered years. The higher latitude of their habitats, earlier birth date, shorter birth period, fewer birth peaks and stronger birth synchrony might be adaptations for strongly seasonal variation in climate and food resources. After the summer solstice when daylight length began to gradually shorten, R. bieti at Mt. Lasha started to breed during the period with the highest environmental temperature and food availability, which implied that photoperiod may be the proximate factor triggering the onset of estrus and mating. It appears that R. bieti coincided conception and mid-lactation with the peak in staple foods, and weaning with the peak in high quality of foods. Thus, food availability was the ultimate factor regulating reproductive seasonality, and photoperiod was the proximate factor fine-turning the coordination between seasonal breeding and food availability.

Distribution of sleeping sites of the Yunnan snub-nosed monkey(Rhinopithecus bieti)in the Samage Forest,China

Sleeping site locations are important to free-ranging primate groups.Sites are strategically selected by primates so as to optimize security,comfort and foraging efficiency.Data were collected on the distribution of sleeping sites of the Yunnan snub-nosed monkey(Rhinopithecus bieti)between Sep 2005 and Sep 2006 at Gehuaqing in Baimaxueshan Nature Reserve,China.We identified 54 sleeping sites,which were used 137 times during the study period.These sleeping sites were distributed throughout the monkey group’s total home range.R.bieti preferred certain sleeping sites over others:63%of the sleeping sites were used 2 or more times in 13 months.Groups reused locations in an unpredictable long-term pattern,but avoided using the same sleeping site on consecutive nights.To reduce the time and energetic costs of travel,monkeys preferred sleeping near commonly used feeding sites.We recorded 124 feeding sites in the home range,which were used 174 times.A total of 27 sleeping sites were also feeding sites,and all remaining sleeping sites were close to feeding sites.There was a positive correlation between the intensity of use of sleeping sites and feeding sites.The present study suggests that the availability and the location of immediate sources of food is a key factor in the choice of sleeping sites.

Dominance hierarchy and social relationships in a group of Captive black-and-white snub-nosed monkeys (Rhinopithecus bietl)

Different types of dominance hierarchies reflect different social relationships in primates. In this study, we clarified the hierarchy and social relationships in a one-male unit of captive Rhinopithecus bieti observed between August 1998 and March 1999. Mean frequency of agonistic behaviour among adult females was 0.13 interactions per hour. Adult females exhibited a linear hierarchy with a reversal of 10.9%, indicating an unstable relationship; therefore, R. bieti appears to be a relaxed/tolerant species. The lack of a relationship between the agonistic ratio of the adult male towards adult females and their ranks indicated that males did not show increased aggression towards low-ranking females. Differentiated female affiliative relationships were loosely formed in terms of the male, and to some extent influenced by female estrus, implying that relationships between the male and females is influenced by estrus and not rank alone. A positive correlation between the agonistic ratio of adult females and their ranks showed that the degree to which one female negatively impacted others decreased with reduction in rank. Similarly, a positive correlation between the agonistic ratio of females and differences in rank suggests that a female had fewer negative effects on closely ranked individuals than distantly ranked ones. These data indicate that rank may influence relationships between females. A steeper slope of regression between the agonistic ratio and inter-female rank differences indicated that the extent of the power difference in high-ranking females exerting negative effects on low-ranking ones was larger during the mating season than the birth season, suggesting that rank may influence the mating success of females.

Niche partitioning between sympatric rhesus macaques and Yunnan snub-nosed monkeys at Baimaxueshan Nature Reserve, China

Here we provide a preliminary assessment of dietary and habitat requirements of two sympatric primate taxa, a ＂simple-stomached＂ and ＂complex-stomached＂ species （Rhinopithecus bieti Colobinae vs. Macaca mulatta Cercopithecinae）, as a basis for illuminating how the two coexist. Of ca. 22 plant food species consumed by the macaques, at least 16 were also eaten by the snub-nosed monkeys. Both species showed a preference for fruits. While the snub-nosed monkeys did not utilize any resources associated with human communities, rhesus macaques did occasionally raid agricultural crops. The mean elevation of the snub-nosed monkey group was 3,218 m, while the mean elevation of the macaque group was 2,995 m. Macaques were also spotted on meadows whereas snub-nosed monkeys evidently avoided these. For both species, mixed deciduous broadleaf/conifer forest was the most frequently used ecotype, but whereas evergreen broadleaf forest （Cyclobalanopsis community） accounted for only 3% of the location records of the snub-nosed monkeys, it accounted for 36% of the location records of the macaques. Groups of the two species usually kept a considerable spatial distance from one another （mean 2.4 km）. One close encounter and confrontation between groups of the two species resulted in the macaque group moving away. Our findings suggest that the coexistence of the two taxa is facilitated via differential macrohabitat use and spatial avoidance. Although divergent habitat-use strategies may reflect interspecific competition, they may also merely reflect different physiological or ecological requirements.

Home range and seasonality of Yunnan snub-nosed monkeys

Home range studies are essential for understanding an animal’s behavioral ecology and for making wildlife conservation efficient.The home range of a group of Yunnan snub-nosed monkeys(Rhinopithecus bieti Milne-Edwards,1897)was estimated using a global positioning system collar from December 2003 to October 2004 in northern Yunnan Province,China.To measure the ranging area of the study group 1291 animal locations were fixed.Based on the 100%minimum convex polygon method,the home range size was approximately 32.8 km2;based on the grid-cell method it was approximately 17.8 km2 using a 250-m grid and 23.3 km2 using a 500-m grid.We assessed seasonal changes in the home range of this monkey population and found a different ranging pattern of from earlier studies.Daily range size was calculated as 4.80±5.81 ha(mean±standard deviation),with a range of 45.66 ha(0.01–45.67 ha).

Dispersal patterns in Yunnan snub-nosed monkeys

Sex-biased dispersal is common in group-living animals.Due to differences in local demographic and environmental factors,sex-biased dispersal presents many irregular patterns.In this study,a habituated,individually identified Yunnan snub-nosed monkey Rhinopithecus bieti group was observed over 9 years;192 dispersal events,including 97 male dispersal events(25 natal dispersal and 72 secondary dispersal)and 95 female dispersal events(34 natal dispersal and 61 secondary dispersal)were observed.Males and females showed different dispersal paths,dispersal ages,and dispersal patterns.Females had 2 dispersal paths,whereas males had 4 paths.In terms of age of dispersal,the male age of natal dispersal was younger than for females.Males prefer single dispersal,whereas females prefer parallel dispersal.Our study indicates that the dispersal pattern of R.bieti should be classified as a bisexual dispersal pattern.The differences in dispersal path,average age at dispersal,and dispersal path pattern indicate that Yunnan snub-nosed monkeys may still retain a loose matrilineal social system.