Rhinopithecus Research Articles

An Assessment of Impacts of Local Communities on the Habitat of the Tonkin Snub-nosed Monkey (Rhinopithecus avunculus) Population in Quan Ba District, Ha Giang Province

The population of the Tonkin Snub-nosed Monkey (Rhinopithecus avunculus) in Cao - Ta - Tung forest of Quan Ba district, Ha Giang province is approximately from 10 to 20 individuals. Because the distribution of this population is located outside of a special-use forest, the habitat of the species is fragmented and continuing to decline due to agricultural expansion and human disturbance. The research results showed that the main livelihood of local people is growing corn and cardamom. There are still activities of forest product exploitation, mainly for firewood. Five major threats to the population of Rhinopithecus avunculus in Cao - Ta - Tung forest are hunting activities, timber logging, non-timber forest product exploitation, deforestation for farming, and cardamom cultivation. The activities of local people in Va Thang 2, Ta Van and Chong Chai villages have a very high level of threat, while Cha Phin and Ban Thang villages have a high level of threat. The expansion of the planting area of cardamom (Amomum tsao) under the forest canopy by local people has made the forest area shrink, which has seriously affected the habitat of the population. In order to protect the habitat and population of the Tonkin Snub-nosed Monkey in Quan Ba district, the following conservation measure should be considered: i) Establish the Quan Ba Tonkin Snub-nosed Monkey Species and Habitat Conservation Area; ii) Take measures to prevent the expansion of cardamom cultivation under the forest canopy; iii) Enhance communication to raise public awareness on this species protection, forest protection as well as biodiversity conservation; and iv) Develop livelihood models for local communities to improve living standards and reduce pressure on forests.

Ontogenetic Development of Sexual Dimorphism in Body Mass of Wild Black-and-White Snub-Nosed Monkey (Rhinopithecus bieti).

Sexual dimorphism exists widely in animals, manifesting in different forms, such as body size, color, shape, unique characteristics, behavior, and sound. Of these, body mass dimorphism is the most obvious. Studies of evolutionary and ontogenetic development and adaptation mechanisms of animals' sexual dimorphism in body mass (SDBM), allow us to understand how environment, social group size, diet, and other external factors have driven the selection of sexual dimorphism. There are fewer reports of the ontogenetic development of sexual dimorphism in body mass in Rhinopithecus. This study explores the ontogenetic development pattern of SDBM in wild black-and-white snub-nosed monkeys (R. bieti), and the causes resulting in extreme sexual dimorphism compared to other colobines. A significant dimorphism with a ratio of 1.27 (p < 0.001) appears when females enter the reproductive period around six years old, reaching a peak (1.85, p < 0.001) when males become sexually mature. After the age of eight, the SDBM falls to 1.78, but is still significant (p < 0.001). The results also indicate that males had a longer body mass growth period than females (8 years vs. 5 years); females in larger breeding units had a significantly higher SDBM than those in smaller ones (2.12 vs. 1.93, p < 0.01). A comparative analysis with other colobines further clarifies that Rhinopithecus and Nasalis, which both have multilevel social organization, have the highest degree of SDBM among all colobines. The large SDBM in R. bieti can be explained through Bergman's and Rensch's rules. Overall, environmental adaptation, a distinctive alimentary system, and a complex social structure contribute to R. bieti having such a remarkable SDBM compared to other colobines. In addition, we found that females' choice for males may not be significantly related to the development of SDBM.

Friend or foe? Using eye-tracking technology to investigate the visual discrimination ability of giant pandas.

The role that visual discriminative ability plays among giant pandas in social communication and individual discrimination has received less attention than olfactory and auditory modalities. Here, we used an eye-tracker technology to investigate pupil fixation patterns for 8 captive male giant pandas Ailuropoda melanoleuca. We paired images (N = 26) of conspecifics against: 1) sympatric predators (gray wolves and tigers), and non-threatening sympatric species (golden pheasant, golden snub-nosed monkey, takin, and red panda), 2) conspecifics with atypical fur coloration (albino and brown), and 3) zookeepers/non-zookeepers wearing either work uniform or plain clothing. For each session, we tracked the panda's pupil movements and measured pupil first fixation point (FFP), fixation latency, total fixation count (TFC), and duration (TFD) of attention to each image. Overall, pandas exhibited similar attention (FFPs and TFCs) to images of predators and non-threatening sympatric species. Images of golden pheasant, snub-nosed monkey, and tiger received less attention (TFD) than images of conspecifics, whereas images of takin and red panda received more attention, suggesting a greater alertness to habitat or food competitors than to potential predators. Pandas' TFCs were greater for images of black-white conspecifics than for albino or brown phenotypes, implying that familiar color elicited more interest. Pandas reacted differently to images of men versus women. For images of women only, pandas gave more attention (TFC) to familiar combinations (uniformed zookeepers and plain-clothed non-zookeepers), consistent with the familiarity hypothesis. That pandas can use visual perception to discriminate intra-specifically and inter-specifically, including details of human appearance, has applications for panda conservation and captive husbandry.

Recent Advances in Genetics and Genomics of Snub-Nosed Monkeys (Rhinopithecus) and Their Implications for Phylogeny, Conservation, and Adaptation.

The snub-nosed monkey genus Rhinopithecus (Colobinae) comprises five species (Rhinopithecus roxellana, Rhinopithecus brelichi, Rhinopithecus bieti, Rhinopithecus strykeri, and Rhinopithecus avunculus). They are range-restricted species occurring only in small areas in China, Vietnam, and Myanmar. All extant species are listed as endangered or critically endangered by the International Union for Conservation of Nature (IUCN) Red List, all with decreasing populations. With the development of molecular genetics and the improvement and cost reduction in whole-genome sequencing, knowledge about evolutionary processes has improved largely in recent years. Here, we review recent major advances in snub-nosed monkey genetics and genomics and their impact on our understanding of the phylogeny, phylogeography, population genetic structure, landscape genetics, demographic history, and molecular mechanisms of adaptation to folivory and high altitudes in this primate genus. We further discuss future directions in this research field, in particular how genomic information can contribute to the conservation of snub-nosed monkeys.

Social and paternal female choice for male MHC genes in golden snub-nosed monkeys (Rhinopithecus roxellana).

Genes of the major histocompatibility complex (MHC) play important roles in vertebrate immunocompetence. MHC genes thus offer females indirect benefits to mate choice through the production of offspring of an optimal MHC genotype. Females may choose males with specific MHC haplotypes, dissimilar MHC genotypes, MHC heterozygous males or MHC-diverse males. We tested these four alternatives for both female social and paternal choice in wild golden snub-nosed monkeys (Rhinopithecus roxellana) by examining overall genetic variability (via microsatellites) and four MHC-genes (DRB1, DRB2, DQA1 and DQB1). Monte Carlo randomization tests showed that MHC dissimilarity was favoured for social choice (males to which females were socially affiliated) and intermediate MHC dissimilarity was favoured in paternal choice (fathers of offspring). No evidence of inbreeding avoidance was found for either social or paternal mates. We found that MHC heterozygotes, higher microsatellite multilocus heterozygosity and higher microsatellites diversity were favoured for social mates, and higher microsatellite diversity was favoured for paternal mates. Independent of male age, we found that the formation of male-female social pairings is significantly predicted by compatibility based on the sharing of MHC haplotypes. However, we found no evidence of independent genetic effects on the duration of male-female social pairings, male social status (achieving OMU leader male status or not), the number of females with which individual leader males paired, the likelihood of potential male-female pairings producing offspring, or whether males fathered offspring or not. Overall, our findings suggest different genetic factors are involved in social and paternal choice in R. roxellana.

Epidemiological Survey and Risk Factor Analysis of 14 Potential Pathogens in Golden Snub-Nosed Monkeys at Shennongjia National Nature Reserve, China

Golden snub-nosed monkeys (Rhinopithecus roxellanae) belong to Class A, the highest level of endangered primate species. Exploring the infection status of potential pathogens in golden snub-nosed monkeys is important for controlling associated diseases and protecting this species. The objective of this study was to investigate the seroprevalence for a number of potential pathogens and the prevalence of fecal adenovirus and rotavirus. A total of 283 fecal samples were collected from 100 golden snub-nosed monkeys in December 2014, June 2015, and January 2016; 26 blood samples were collected from 26 monkeys in June 2014, June 2015, January 2016 and November 2016 at Shennongjia National Reserve in Hubei, China. The infection of 11 potential viral diseases was examined serologically using an Indirect Enzyme-linked Immunosorbent Assay (iELISA) and Dot Immunobinding Assays (DIA), while the whole blood IFN-γ in vitro release assay was used to test tuberculosis (TB). In addition, fecal Adenovirus and Rotavirus were detected using Polymerase Chain Reaction (PCR). As a result, the Macacine herpesvirus-1 (MaHV-1), Golden snub-nosed monkey cytomegalovirus (GsmCMV), Simian foamy virus (SFV) and Hepatitis A virus (HAV) were detected with the seroprevalence of 57.7% (95% CI: 36.9, 76.6), 38.5% (95% CI: 20.2, 59.4), 26.9% (95% CI: 11.6, 47.8), and 7.7% (95% CI: 0.0, 84.2), respectively. Two fecal samples tested positive for Adenovirus (ADV) by PCR, with a prevalence of 0.7% (95% CI: 0.2, 2.5), and further, the amplification products were sequenced. Phylogenetic analysis revealed that they belonged to the HADV-G group. However, other pathogens, such as Coxsackievirus (CV), Measles virus (MeV), Rotavirus (RV), Simian immunodeficiency virus (SIV), Simian type D retroviruses (SRV), Simian-T-cell lymphotropic virus type 1 (STLV-1), Simian varicella virus (SVV), Simian virus 40 (SV40) and Mycobacterium tuberculosis complex (TB) were negative in all samples. In addition, a risk factor analysis indicated that the seroprevalence of MaHV-1 infection was significantly associated with old age (≥4 years). These results have important implications for understanding the health status and conservation of the endangered golden snub-nosed monkey population at Shennongjia Nature Reserve.

Snub-nosed monkeys have taught me important life lessons.

Snub-nosed monkeys have taught me important life lessons.

Social and paternal female choice for male MHC genes in golden snub-nosed monkeys (Rhinopithecus roxellana)

Social and paternal female choice for male MHC genes in golden snub-nosed monkeys (<i>Rhinopithecus roxellana</i>)

Infanticide in golden snub-nosed monkeys with multilevel society.

Infanticide in golden snub-nosed monkeys with multilevel society.

Gut microbiome variations in Rhinopithecus roxellanae caused by changes in the environment

BackgroundThe snub-nosed monkey (Rhinopithecus roxellanae) is an endangered animal species mainly distributed in China and needs to be protected. Gut microbiome is an important determinant of animal health and population survival as it affects the adaptation of the animals to different foods and environments under kinetic changes of intrinsic and extrinsic factors. Therefore, this study aimed to elucidate gut fecal microbiome profiles of snub-nosed monkeys affected by several extrinsic and intrinsic factors, including raising patterns (captive vs. wild), age, sex, and diarrheal status to provide a reference for making protection strategies.ResultsThe 16S rRNA gene sequencing was firstly used to pre-check clustering of 38 fecal samples from the monkeys including 30 wild and 8 captive (5 healthy and 3 diarrheal) from three Regions of Shennongjia Nature Reserve, Hubei Province, China. Then the 24 samples with high-quality DNA from 18 wild and 6 captive (4 healthy and 2 diarrheal) monkeys were subjected to shotgun metagenomic sequencing to characterize bacterial gut microbial communities. We discovered that the raising pattern (captive and wild) rather than age and sex was the predominant factor attributed to gut microbiome structure and proportionality. Wild monkeys had significantly higher bacterial diversity and lower Bacteroidetes/Firmicutes ratios than captive animals. Moreover, the gut microbiomes in wild healthy monkeys were enriched for the genes involved in fatty acid production, while in captive animals, genes were enriched for vitamin biosynthesis and metabolism and amino acid biosynthesis from carbohydrate intermediates. Additionally, a total of 37 antibiotic resistant genes (ARG) types were detected. Unlike the microbiome diversity, the captive monkeys have a higher diversity of ARG than the wild animals.ConclusionTaken together, we highlight the importance of self-reprogramed metabolism in the snub-nosed monkey gut microbiome to help captive and wild monkeys adapt to different intrinsic and extrinsic environmental change.

Do golden snub-nosed monkeys use deceptive alarm calls during competition for food?

Tactical deception can be beneficial for social animals during intra-specific competition. However, the use of tactical deception in wild mammals is predicted to be rare. We tested whether a food-provisioned free-ranging band of golden snub-nosed monkeys (Rhinopithecus roxellana) use alarm calls in a functionally deceptive manner to gain access to food resources, whether the rate of deceptive alarm calls varies among individuals, and whether there are any counter-deception behaviors. We used a hexagonal camera array consisting of 10 cameras to record videos during feeding, which allowed us to identify individual alarm callers. We found evidence that these monkeys use deceptive alarms and that adult females were more likely to use such calls than other individuals. The monkeys increased their rates of response to alarm calls when competition for food was high. However, we found no direct evidence of any counter-deception strategies.

The Entire 80-year Research History of Sichuan Snub-nosed Monkeys (Rhinopithecus roxellana): A Citespce-based Bibliometric Study

The Sichuan snub-nosed monkey (Rhinopithecus roxellana) is a flagship species that has received worldwide attention, and its study is of great importance. In this paper, we analyzed the entire 80 years of research on Sichuan snub-nosed monkeys worldwide with the web of science database as the basic data source and the visualization software CiteSpace to summarize the status of Sichuan snub-nosed monkey research. The study shows that: 1. Throughout the 80 years of Sichuan snub-nosed monkey research, it can be summarized into three developmental stages. During the 57 years from 1942 to 1998, which was the beginning stage of Sichuan snub-nosed monkeys; while during the 8 years from 1999 to 2006, which was the development stage of Sichuan snub-nosed monkeys; from 2007 to the present, which was the peak stage of Sichuan snub-nosed monkey’s research. 2. Investigating the countries/regions, institutions, authors, and core journals of Sichuan snub-nosed monkey research throughout the past 80 years, we found that the research on Sichuan snub-nosed monkey, as an endemic species in China, is still dominated by Chinese research units and personnel, and the research units and researchers from various countries or regions are very close in their research relationships, and the papers published by these researchers are also concentrated in some core journals. 3. Throughout its 80-year history, the subject of Sichuan snubnosed monkeys has undergone two explosive periods, after which it gradually reached saturation in the research field.

Stepping Stone Strategy: A Cost-Effective Way to Address Habitat Fragmentation of Endangered Wildlife in Montane Forest

Habitat fragmentation affects the survival of wildlife and is a main threat to biodiversity. Corridors are frequently used to alleviate habitat fragmentation. However, corridors are costly and often ineffective in practice. Endangered species in montane regions are particularly affected by habitat fragmentation and therefore require economic and efficient conservation strategies. We propose a stepping stone strategy (SSS) to deal with habitat fragmentation threatening an endangered primate, the black-and-white snub-nosed monkeys ( Rhinopithecus bieti ). We selected the southern range of R. bieti as the study area, which covers 3,580 km 2 . We evaluated the habitat status and formulated an SSS based on the dispersal ability of an adult male R. bieti . Six sustainable habitat patches and 340 natural stepping stones were detected. Thirteen artificial stepping stones are needed to establish weak connectivity of habitats. Forty-four stepping stones are proposed as key stepping stones for attaining strong connectivity. The SSS is projected to incur substantially less pecuniary investment than the corridor strategy (0.06 million versus 5.65 million, USD). We conclude that 5 steps are needed for the SSS: (a) assessing the status of habitats to plan restorative intervention activities, (b) designing artificial stepping stones to weakly link sustainable habitats, (c) proposing corridors to allow for a stable connection between sustainable habitats, (d) identifying key stepping stones to establish small protected area, and (e) recovery of fragmented habitat and reinstatement of sustainable habitat. Our study suggests that SSS is a cost-effective and practical way for maintaining connectivity and supporting habitat recovery for endangered wildlife in montane regions.

The Delineation and Ecological Connectivity of the Three Parallel Rivers Natural World Heritage Site.

Landscape connectivity refers to the degree of continuity between the spatially structured units of a landscape. Ecological connectivity can characterise the degree to which ecological functional areas are connected in terms of function and ecological processes. In this study, the landscape pattern index and ecosystem service values were used to evaluate the ecological functional resistance of each landscape type, taking the Three Parallel Rivers Natural World Heritage Site as an example and the habitat distribution and population size of the Yunnan snub-nosed monkey as a reference. The minimum cost distance model, combined with the barrier impact index (BEI) and ecological connectivity index (ECI), was used to determine the degree of barrier impact on the study area and the ecological connectivity of the core reserve of the heritage site in both 2000 and 2020. The resistances of the different land types and landscape heterogeneity to the ecological function of species migration between the core protected areas of the heritage site were, in descending order, those of the forest, shrubs and grass, water, unused land, cultivated land, and built-up land. In 2020, the study area had a large BEI, with areas such as built-up areas, major roads, the sides of large rivers, and arable land being significant contributors to the blockage of landscape connectivity. The overall landscape connectivity in the study area was generally low, with clear spatial differentiation and a three-column parallel distribution pattern influenced by the topography and landscape. With the adjustment of the core reserve boundaries of the heritage site, the proportion of areas with high connectivity (ECI = 4-5) increased from 11.31% in 2000 to 34.36% in 2020. This increased landscape connectivity was conducive to the migration and reproduction of large terrestrial animals, such as the Yunnan snub-nosed monkey, with increasing numbers of populations and individuals. This study provides theoretical and methodological insights into the delineation and conservation of natural heritage sites and landscape connectivity.

Characterizing the Gut Microbiota of Eurasian Otter (Lutra lutra chinensis) and Snub-Nosed Monkey (Rhinopithecus roxellana) to Enhance Conservation Practices in the Foping National Nature Reserve of China.

Understanding the interaction between the microbial composition in the habitat and the gut of wildlife will contribute to conservation efforts since changes in the gut microbiome have been proven to influence the healthy and nutritional status of the host. This study analyzed the relationship between soil microbes and the microbial diversity and structure of the distal gut of the terrestrial golden snub-nosed monkey and Eurasian otter in the Foping National Nature Reserve (FNNR). A total of 15 otter fecal samples and 18 monkey fecal samples were collected from which 5 and 6 samples, respectively, were randomly selected for microbiome analysis. The remaining samples were used for fecal short-chain fatty acids (SCFAs) analysis. Soil samples from the otter and monkey habitats at each sampling point (eight in total) were also collected for microbiome analysis. The microbial phyla with the greatest relative abundance in soil or animal samples were Proteobacteria (41.2, 32.7, and 73.3% for soil, otters, and monkeys, respectively), Firmicutes (0.4% soil, 30.1% otters, and 14.4% monkeys), Bacteroidota (5.6% soil, 17.0% otters, and 8.3% monkeys), and Acidobacteriota (24.6% soil, 1.7% otters, and 0.1% monkeys). The estimation of alpha diversity indices revealed that the feature, Chao1, and Shannon indices of the soil microbiome were the greatest (p &lt; 0.01) among the three groups, followed by those of the otter microbiome and those of the monkey microbiome (p &lt; 0.01). Beta diversity analyses confirmed differences in the microbiota of the three types of samples. The determination of SCFA concentration in feces revealed that total volatile fatty acids, acetic acid, and isovaleric acid were greater (p &lt; 0.05) in otters than in monkeys, while propionic acid followed the opposite pattern (p &lt; 0.05). Correlation analysis of the microbiome and SCFA contents showed that propionic acid was positively correlated with significantly different bacterial groups, while acetic and butyric acid and total volatile acids were negatively correlated. This study confirmed that the fecal microbes of Eurasian otters and golden snub-nosed monkeys in the reserve are related to the soil microbial communities of their habitats, but they have different bacterial community structures and compositions, and there are different SCFA metabolic patterns in the gut of the two animals. The present study will help to improve wildlife protection in the FNNR.

Consistency of limb preference across unimanual feeding, bipedal locomotion, and social grooming in golden snub-nosed monkeys (Rhinopithecus roxellana)

ABSTRACT The golden snub-nosed monkey (Rhinopithecus roxellana) is a typical arboreal group-living Old World primate. While limb preference has been extensively studied in this species, limb preference consistency has not yet been explored. Here, based on 26 R. roxellana adults, we investigated whether individuals exhibit consistent motor biases in manual- (e.g., unimanual feeding and social grooming) and foot-related (e.g., bipedal locomotion) tasks and whether limb preference consistency is influenced by increased social interactions during social grooming. Results showed no consistency in the direction or strength of limb preference among tasks, except for lateral strength in handedness for unimanual feeding and footedness in the initiation of locomotion. Population-level foot preference was only found among right-handers. Marked lateral bias was found in unimanual feeding, indicating that it may be a sensitive behavioural measure for assessing manual preference, especially for provisioned populations. This study not only improves our understanding of the relationship between hand and foot preference in R. roxellana but also reveals potential differential hemispheric regulation of limb preference and the influence of increased social interaction on handedness consistency.

Assessing the Impact of Village Development on the Habitat Quality of Yunnan Snub-Nosed Monkeys Using the INVEST Model.

Simple SummaryThe Yunnan snub-nosed monkey is one of the most endangered species on the IUCN Red List. The study of its population and habitat quality is important in identifying opportunities for balancing socio-economic development against species conservation in the area’s villages. Such balances are important to protecting and improving habitat diversity and biodiversity. Our habitat quality analysis indicates that increases in socio-economic developments in the villages around the habitat area have decreased both the habitat area and the habitat quality over time. This has resulted in a decline in biodiversity persistence, resilience, and breadth. It also has exacerbated the risk of declining species populations, potentially to extinction. Though focused on the Yunnan snub-nosed monkey, our approach toward the assessment of habitat quality based on species habitat suitability introduces a new perspective for assessing village development impacts on the habitat quality for the conservation of other species.The habitats of the already endangered Yunnan snub-nosed monkey (Rhinopithecus bieti) are degrading as village economies develop in and around these habitat areas, increasing the depopulation and biodiversity risk of the monkey. The paper aims to show the areas of these monkeys’ high-quality habitats that are at highest risk of degradation by continued village development and hence be the focus of conservation efforts. Our analysis leveraged multiple tools, including primary component analysis, the InVEST Habitat-Quality model, and GIS spatial analysis. We enhanced our analysis by looking at habitat quality as it relates to the habitat suitability for the monkey specifically, instead of general habitat quality. We also focused on the impact of the smallest administrative scale in China—the village. These foci produced a clearer picture of the monkeys’ and villages’ situations, allowing for more targeted discussions on win–win solutions for both the monkeys and the village inhabitants. The results show that the northern habitat for the monkey is currently higher quality than the southern habitat, and correspondingly, the village development in the north is lower than in the south. Hence, we recommend conservation efforts be focused on the northern areas, though we also encourage the southern habitats to be protected from further degradation lest they degrade beyond the point of supporting any monkeys. We encourage developing a strategy that balances ecological protection and economic development in the northern region, a long-term plan for the southern region to reduce human disturbance, increase effective habitat restoration, and improve corridor design.

The Influence of Environmental Variables on Home Range Size and Use in the Golden Snub-Nosed Monkey (Rhinopithecus roxellana) in Tangjiahe National Nature Reserve, China.

Simple SummaryThe objectives of our study were to determine the seasonal home range size variation, and to determine the fraction of variation in home range use explained by environmental variables. We found that the core home range size of the golden snub-nosed monkey in Tangjiahe National Nature Reserve varied seasonally. The environmental variables in spring and summer explained a large part of home range use intensity, while the environmental variables in autumn and winter explained a moderate fraction and no fraction of home range use intensity, respectively. Water sources, tree density, and dominant trees of Chinese wingnut (Pterocarya stenoptera) were the important environmental factors determining home range use.Accurate descriptions of home ranges can provide important information for understanding animal ecology and behavior and contribute to the formulation of conservation strategies. We used the grid cell method and kernel density estimation (KDE) to estimate the home range size of golden snub-nosed monkeys (Rhinopithecus roxellana) in Tangjiahe National Nature Reserve. We also used Moran’s eigenvector maps analysis and variation partitioning to test the influence of environmental variables on home range use. The seasonal home range size was 15.4 km2 in spring, 11.6 km2 in summer, 13.7 km2 in autumn, and 15.6 km2 in winter, based on the grid cell method. The seasonal core area of 50% KDE was 9.86 km2 in spring, 5.58 km2 in summer, 7.20 km2 in autumn, and 4.23 km2 in winter. The environmental variables explained 63.60% of home range use intensity in spring, 72.21% in summer, 26.52% in autumn, and none in winter, and some environmental variables contributed to the spatial variation in home range use intensity. Water sources, tree density, and dominant trees of Chinese wingnut (Pterocarya stenoptera) were the important environmental factors determining home range use. These environmental factors require protection to ensure the survival of the golden snub-nosed monkey.

Female demographic changes contribute to the maintenance of social stability within a primate multilevel society

Various primate species, including golden snub-nosed monkeys, Rhinopithecus roxellana , form highly complex multilevel social systems. Breeding bands of snub-nosed monkeys maintain stability even though multiple one-male units (OMUs) within a band do not appear to engage in affiliative behaviours among units. As such, female dispersal within breeding bands may be a key factor related to social stability in these complex social systems. However, how individual and group behaviours influence both the formation of this complex social system and the maintenance of social stability within it remain to be fully elucidated. In the current study, based on 16 years of accumulated data, we investigated female dispersal in a wild population of golden snub-nosed monkeys in the Qinling Mountains of China. Using social network analysis and dynamic social modelling, we found that male take-over had no influence on the dominance rank of an OMU, whereas the number of breeding females within an OMU had a significant positive effect on rank. Both the number of breeding females and the number of females entering an OMU had significant positive effects on eigenvector centrality of an OMU. Female dispersal between OMUs decreased the clustering coefficient and reduced the risk of subgroup formation. In addition, female kinship matrices between units were not significantly correlated with association behaviour patterns. Thus, this study sheds light on the internal mechanisms that drive social stability in a complex primate social system. • One-male units in a golden snub-nosed monkey band showed few affiliative behaviours. • Multiple females dispersed among units during the 16-year study period. • Social network analysis showed that female dispersal can maintain social stability. • Female dispersal, not male take-over, affected unit hierarchical rank. • Female kinship did not influence association patterns among one-male units.

Incorporating interspecific relationships into species distribution models can better assess the response of species to climate change, a case study of two Chinese primates

Whether the distribution of species can track future changes in climate will ultimately determine their survival. However, traditional predictions of species distributions in response to climate change often ignore the effects of biotic interactions. Here, we incorporated interspecific competition into SDMs (Species distribution models) to assess the distribution of two species endemic to China, namely the Sichuan snub-nosed monkey (Rhinopithecus roxellanae) and Tibetan macaque (Macaca thibetana), in response to climate change. Due to overlap areas in the distributions of both species, niche competition between the Sichuan snub-nosed monkey and Tibetan macaque was observed, and the former was less competitive in terms of theirability to source food and their reproductive capacity. The area where niche overlap between the Sichuan snub-nosed monkey and Tibetan macaque occurs accounts for half of the suitable habitat for the former, suggesting that the Sichuan snub-nosed monkey cannot use this habitat effectively. Both species are predicted to lose more than 70 % of their suitable habitat by the 2050s, and the altitude of suitable habitat will likely decrease. Bio3 (Isothermality) and Bio13 (Precipitation of Wettest Month) were the most important climatic variables affecting the distribution of the Sichuan snub-nosed monkey and Tibetan macaque, respectively. The suitable habitat of the Sichuan snub-nosed monkey and Tibetan macaque was fragmented into several isolated pieces, which requires that ecological restoration should be carried out in advance. We demonstrated that the incorporation of interspecific competition into SDMs can accurately assess the response of species to future climate change, as less competitive species cannot effectively use their suitable habitat.