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Background: Testosterone plays a crucial role in regulating sexual behavior among non‐human primates, working primarily by increasing copulatory behavior and sexual motivation. In this study, we analyzed fecal testosterone levels in five adult male Tibetan macaques (Macaca thibetana) living freely in the Huangshan National Reserve in Anhui Province. The aim was to investigate the relationships between fecal testosterone levels and sexually motivated behaviors. Methods: We collected a total of 426 fecal samples and observed approximately 453 h of focal sampling behavioral data. Sexually motivated behaviors were categorized as sexual chase, grimace, and sexual‐inspection. Results: The results showed a positive correlation between sexually motivated behaviors and copulatory behavior. Furthermore, all the three sexually motivated behaviors, including sexual chase, grimace, and sexual‐inspection, were positively correlated with fecal testosterone levels. Conclusion: Our results demonstrated positive correlations between sexually motivated behaviors and fecal testosterone in free‐ranging Tibetan macaques. [ABSTRACT FROM AUTHOR]

Adoption is an important form of allomaternal care in nonhuman primates, with implications for reproductive output and infant survival. Here, we report a kidnapping that became an adoption of a 3-week-old infant by a mother with her own infant in Tibetan macaques (Macaca thibetana). The adoptive mother nursed her "new" infant (allonursing), the first observation of this behavior in the species. The case provided a natural experiment for comparing how a female copes with a heavier burden of care for both her biological infant and another female's infant, compared to mothers caring for only one infant. Our results showed that the adoptive female spent more time foraging and resting, and less time in group social activity compared to females with a single infant. The adoptive female showed more instances of social bridging. Although the duration of post-bridging grooming received from group members decreased, the frequency of such grooming increased. We discuss this adoption with reference to possible factors involved in the evolution of adoption and allonursing behavior in Tibetan macaques. [ABSTRACT FROM AUTHOR]

Predicting the spatial distribution of species and suitable areas under global climate change could provide a reference for species conservation and long‐term management strategies. Macaca thibetana and Macaca arctoides are two endangered species of Chinese macaques. However, limited information is available on their distribution, and their habitat needs lack proper assessment due to complicated taxonomy and less research attention. In recent years, scholars widely used the maximum entropy (MaxEnt) model to predict the impact of global climate and certain environmental factors on species distribution. Therefore, we used the MaxEnt model to predict the spatiotemporal distribution of both macaque species under six climate change scenarios using occurrence and high‐resolution ecological data. We identified climatic factors, elevation, and land cover that shape their distribution range and determined shifts in their habitat range. The results demonstrated that temperature range, annual precipitation, forest land cover, and temperature seasonality, including the precipitation of the driest month are the main factors affecting their distribution. Currently, M. thibetana is mainly concentrated in central, eastern, southern, and southwestern China, and M. arctoides is mainly concentrated in three provinces (Yunnan, Guangxi, and Guangdong) in southern China. The MaxEnt model predicted that the suitable habitat for both species will increase with increased greenhouse emission scenarios. We also found that with the further increase in greenhouse emissions M. thibetana is expected to migrate to western China, and M. arctoides is expected to migrate to western or eastern China. This reinterpretation of the distribution of M. thibetana and M. arctoides in China, and predicted potential suitable habitat and possible migration direction, may provide new insights into the future conservation and management of these two species. Highlights: Potential macaque distributions were predicted using different climate change scenarios.Macaque distributions were compared under present and future climate conditions.Suitable habitat areas for Macaca thibetana and Macaca arctoides are expected to increasing.Annual precipitation and annual temperature affected distribution.We believe the two species are migrating to the west of China to adapt to climate change. [ABSTRACT FROM AUTHOR]

Immigrant males employed a range of species-specific social strategies to facilitate integration into a new social group for establishing stable dominant ranks and affiliative relationships with unfamiliar competitors who require them to adapt their behavior. However, less is known whether the social strategies of integration were individual-specific. In this study, a case that nine adult males immigrated into the subject social group provided a natural experiment to investigate the variation of social strategies between the bluff and unobtrusive immigrant males during integration into a new social group. We followed the wild YA1 Tibetan macaque group and collected the behavioral data from August 2021 to May 2022. The results showed that the bluff and unobtrusive immigrant males faced similar social pressure from intrasexual individuals in the target social group during both the prospecting and integrating stages. During the prospecting stage, the bluff and unobtrusive immigrant males formed “attempt strategies” to seek and establish social relationships with unfamiliar individuals in a new group. The bluff immigrant males formed affiliative relationships with high-ranking females and resident males whereas the unobtrusive immigrant males formed affiliative relationships with low-ranking females during the integrating stage. Our results firstly provided quantitative methods to distinguish prospecting and integrating stages during immigration processes. This case study also demonstrated that the bluff and unobtrusive immigrant males formed varied social strategies. Our results provided new insight into understanding the individual-specific social strategies of immigrant males during integration into a new social group.

For close to 50 years, my research has focused on social relationships and social structure, particularly in macaques, and has been marked by a gradual broadening of scope. Supported by open-minded parents, I followed a once unconventional path into field primatology largely by ignoring distinct gender-based ideas about appropriate occupations for women that were prevalent when I was a child. Later, as Robert Hinde's PhD advisee, I benefited enormously from his mentoring and from the transformative experience he provided. I began by examining infant social development in free-ranging rhesus monkeys and the integration of infants into the kinship and dominance structures of their groups. I gradually branched out to look at (1) kinship and dominance in additional age classes and macaque species, (2) additional aspects of social structure (reciprocity, agonistic support, tolerance, cooperation, conflict management), (3) mechanisms and organizing principles (e.g., attraction to kin and high rank, intergenerational transmission, demography, reciprocity, social style, time constraints) and (4) evolutionary underpinnings of social relationships and structure (e.g., parental investment, kin selection, socioecology, phylogeny, biological markets). For much of this journey, I have been accompanied by talented PhD students who have enriched my experience and whom I am now proud to call colleagues and friends. It is gratifying to realize that my career choice is no longer considered as unconventional as it once was. [ABSTRACT FROM AUTHOR]

Simple Summary: Seed dispersal by frugivores is critical to forest regeneration. However, the Tibetan macaque's seed dispersal function and the effect of seed physical characteristics on seed dispersal effectiveness need to be confirmed. We not only demonstrated that Tibetan macaques could act as seed dispersers, but we also investigated the effect of seed physical characteristics on gut passage time and seed damage rates. Smaller seeds are less likely to be damaged and remain for longer periods of time, whereas larger and heavier seeds are defecated more quickly. In our experiments, the seed-to-shell investment rate had no effect on the damage rate. Understanding the role of seed dispersal in primates can aid in the understanding of seed dispersal symbiosis. There are numerous ecological and evolutionary implications for the ability of frugivores to predate on fruits and consume or disperse their seeds. Tibetan macaques, which are considered important seed predators, typically feed on fruits or seeds. However, systematic research into whether they have a seed dispersal function is still lacking. Endozoochory allows seeds to disperse over greater distances by allowing them to remain in the animal's digestive tract. Consumption of fruit may not imply effective seed dispersal, and the physical characteristics of seeds (e.g., size, weight, specific gravity, etc.) may influence the dispersal phase's outcome. We conducted feeding experiments with three captive Tibetan macaques (Macaca thibetana) and nine plant seeds to determine the influence of seed characteristics on Tibetan macaques' early stages of seed dispersal. The results revealed that the percentage of seed destruction (PSD) after ingestion was 81.45% (range: 15.67–100%), with the PSD varying between plant species. Among the three passage time parameters, the transit time (TT) (mean: 18.8 h and range: 4–24 h) and the time of seed last appearance (TLA) (mean: 100.4 h and range: 48–168 h) differed significantly between seed species, whereas the mean retention time (MRT) (mean: 47.0 h and range: 32–70.3 h) did not. In terms of model selection, PSD was influenced by seed size, weight, volume, and specific gravity; TT was influenced by seed-to-shell investment rate, weight, volume, and specific gravity; and TLA was influenced only by seed size. These findings imply that seeds with a smaller size, specific gravity, volume, and greater weight pass more easily through the monkeys' digestive tracts. Particularly, seeds with a mean cubic diameter (MCD) of <3 mm had a higher rate of expulsion, larger volume, and weight seeds pass faster, while smaller remained longer. Tibetan macaques, as potential seed dispersers, require specific passage time and passage rates of small or medium-sized seeds. Larger and heavier seeds may be more reliant on endozoochory. Tibetan macaques have the ability to disperse seeds over long distances, allowing for gene flow within the plant community. [ABSTRACT FROM AUTHOR]

Growing evidence suggested that males suffer energetic costs from sexual behavior, males should discriminate among receptive females due to their reproductive quality, and deservedly, they would prefer females during the fertile phase. However, in species with females concealing their ovulation, males cannot identify the females’ fertile phase, and then what are the criteria for males to select their female partners? To answer this question, we collected behavioral data spanning two consecutive years (from February 2017 to January 2019) to investigate the effects of female individual, social and sexual traits on male consort partner choice in Tibetan macaques (Macaca thibetana), a species characterized by distinct seasonal breeding and female concealed ovulation, at Mt. Huangshan, China. Results showed that, in terms of individual traits, males prefer to consort with young/middle-aged, but not old or high-fecundity females; in terms of social traits, males did not engage in more consortship with high-ranking females or their previous non-sexual “friends”; in terms of sexual traits, males were more likely to consort with lower-polyandry females (the level of diversity of the female sexual solicitation). Besides, our results also showed that, compared to other males, alpha males consort more with higher-ranking and lower-polyandry females. Our study suggested that males selected their consort partner based on female sexual traits rather than individual and social traits. Contrary to the previous insights of sexual selection that emphasized female choice and male-male competition, the current study focused on male consort partner choice to provide new insights into the co-evolution of female concealed ovulation and male mating decisions.

In group‐living mammals, an individual's fitness depends, in part, on the quality of social relationships it has with others. Among species of nonhuman primates in which one sex is philopatric, individuals of that sex often develop strong social bonds and alliances with closely related kin. Less is known regarding the social processes used by dispersing adults to form stable bonds with nonkin in their new group. From May to December 2009, April to August 2010, September to December 2011, and February to May 2012, we collected data on grooming interactions in wild Tibetan macaques (Macaca thibetana), a female philopatric species, at Mt. Huangshan, China. Our goal was to compare social interactions and bond formation between resident males, recent immigrant males, and resident females. Our results indicate that recent immigrant males formed stable partner relationships with a small number of resident females and groomed these females more frequently or for longer than they received grooming. In contrast, resident males switched female grooming partners more frequently, received more grooming than they gave, and formed relationships with a greater number of female partners. We argue that the ability of recent immigrant male Tibetan macaques to maintain strong and persistent social bonds with a small set of resident adult females is a primary factor that enables them to establish residence in a new multimale–multifemale group. The present study provides new and important insights into the integrated social strategies used by dispersing males and resident females to maintain group stability. Highlights: Recent immigrant male Tibetan macaques establish strong social bonds and persistent partnerships with a small number of resident females as a social tool to integrate into their new group.In contrast, males who are long‐term residents of the group, frequently change female partners and exhibit less stable partner relationships.The study provides new and important insights into the integrated social strategies used by recent immigrant males, long‐term resident males, and resident females in maintaining group cohesion in a multimale–multifemale primate society. [ABSTRACT FROM AUTHOR]

The distribution and availability of microbes in the environment has an important effect on the composition of the gut microbiome of wild vertebrates. However, our current knowledge of gut-environmental interactions is based principally on data from the host bacterial microbiome, rather than on links that establish how and where hosts acquire their gut mycobiome. This complex interaction needs to be clarified. Here, we explored the relationship between the gut fungal communities of Tibetan macaques (Macaca thibetana) and the presence of environmental (plant and soil) fungi at two study sites using the fungal internal transcribed spacer (ITS) and next generation sequencing. Our findings demonstrate that the gut, plant and soil fungal communities in their natural habitat were distinct. We found that at both study sites, the core abundant taxa and ASVs (Amplicon Sequence Variants) of Tibetan macaques' gut mycobiome were present in environmental samples (plant, soil or both). However, the majority of these fungi were characterized by a relatively low abundance in the environment. This pattern implies that the ecology of the gut may select for diverse but rare environmental fungi. Moreover, our data indicates that the gut mycobiome of Tibetan macaques was more similar to the mycobiome of their plant diet than that present in the soil. For example, we found three abundant ASVs (Didymella rosea , Cercospora , and Cladosporium) that were present in the gut and on plants, but not in the soil. Our results highlight a relationship between the gut mycobiome of wild primates and environmental fungi, with plants diets possibly contributing more to seeding the macaque's gut mycobiome than soil fungi. [ABSTRACT FROM AUTHOR]

Coordination and consensus in collective behavior have attracted a lot of research interest. Although previous studies have investigated the role of compromisers in group consensus, they provide little insight into why compromisers would allow such social arrangements to persist. In this study, the potential relationship between group movements and conflict management in Tibetan macaques in Anhui province, China, was investigated using hierarchical cluster analyses. Some members with higher social centrality or social rank often formed a front-runner cluster during group movements. They had higher leadership success than individuals outside the front-runner cluster. Other members with lower social centrality or social rank often followed the group movements initiated by the front-runner cluster, and thus formed the compromiser cluster. Compromisers' proximity relations with front-runners increased with their following scores to front-runners. Compromisers had fewer events of being attacked when they followed group movements initiated by the front-runners. The compromising process made compromisers lose the choice of direction preference, but it could increase their individual safeties. This trade-off suggests that compromisers play a role of decision-maker in coordination and consensus scenarios among social animals. [ABSTRACT FROM AUTHOR]

Consortship has been defined as a temporary association between an adult male and an estrous/receptive female. It has been considered as male mating strategies to improve male mating success and potential reproductive success. However, the female roles have been more or less neglected, and thus, less is known about female behavioral strategies during the consortship periods. In this study, during the two consecutive mating seasons, we collected behavioral data of free-ranging Tibetan macaques (Macaca thibetana) habituated in Mt. Huangshan, China, to investigate female behaviors when she was consorted by an adult male. The results showed that (a) females were more likely to approach and exhibit sexual solicitation to their consorting males during the consorted period, and females also exhibited less approach to their nonconsorting males; (b) females exhibited strong responses (either departed distantly or formed affiliative relationships with their consorting male partner) when their consorting males mated with rival females or showed sexual motivation toward rival females; (c) female preferences were positively correlated to the duration of consortships and the frequencies of ejaculation copulations, independent of the social ranks of their consorting male partners. Our results suggested that female strategies played much more important roles in forming and maintaining consortship than previously assumed. It provides new insight into understanding female adaptive strategies to male strategies by forming consortships in multimale-multifemale primate species when males could not identify female's fertile phase accurately. [ABSTRACT FROM AUTHOR]

Although recent studies have revealed that gut fungi may play an important functional role in animal biology and health, little is known concerning the effects of anthropogenic pressures on the gut mycobiome. Here, we examined differences of the gut mycobiome in wild and captive populations of Tibetan macaques (Macaca thibetana) targeting the fungal internal transcribed spacer (ITS) and using next generation sequencing. Our findings demonstrate that the diversity, composition, and functional guild of the Tibetan macaque gut mycobiome differ across populations living in different habitats. We found that Tibetan macaques translocated from the wild into a captive setting for a period of 1 year, were characterized by a reduction in fungal diversity and an increase in the abundance of potential gut fungal pathogens compared to wild individuals. Furthermore, we found that the relative abundance of two main fungal guilds of plant pathogens and ectomycorrhizal fungi was significantly lower in captive individuals compared to those living in the wild. Our results highlight that, in addition to bacteria, gut fungi vary significantly among individuals living in captive and wild settings. However, given limited data on the functional role that fungi play in the host's gut, as well as the degree to which a host's mycobiome is seeded from fungi in the soil or ingested during the consumption of plant and animal foods, controlled studies are needed to better understand the role of the local environment in seeding the mycobiome. [ABSTRACT FROM AUTHOR]

Previous researches have highlighted the finding that the availability of food resources plays an important role in reshaping the gut microbiota of wild animals as they to adapt to the surrounding habitat. The gut microbial characteristics were examined in Tibetan macaques (Macaca thibetana) from eastern China (Huangshan, Anhui), but little is known about other geographical populations. Herein, we collected 40 fecal samples of Tibetan macaques from the Labahe Natural Reserve in western China over four seasons and analyzed the seasonal variation of gut microbiota using 16S rRNA gene V3–V4 sequencing. The analysis showed that gut microbial diversity and composition varied by season. Autumn exhibited the lowest alpha diversity and remarkably separated from the other three seasons for beta diversity. There were statistically significant differences in the composition of gut microbiota during different seasons. Autumn presented the lowest Firmicutes/Bacteroidetes ratio while winter had the highest. The family Ruminococcaceae and Lactobacillaceae within Firmicutes accounted for a high proportion in each season, but the abundance of Lactobacillaceae was significantly lower in winter. During autumn, Preotella, which can utilize carbohydrates increased significantly. Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt) prediction revealed that metabolism of cofactors of vitamin pathways and glycan biosynthesis pathways were highly enriched in autumn. Our results revealed that the gut microbiota potentially play an important role in the adaptation of wild Tibetan macaques to the seasonal fluctuations of food availability, which may contribute to the conservation of this endangered species.

During a relatively long period of growth, immature individuals rely on their mothers to obtain nutrition, and a good environment for learning social skills needed to cope with complex environments in adulthood. In this study, we collected the behavioral data of Tibetan macaques (Macaca thibetana) to investigate the effects of females’ social rank on the development of social relationships among their immature offspring from November to June 2021. The results show that there was no difference in the rate/type of social play and grooming among infants. However, among juveniles and adolescents, the higher their mother’s social rank, the higher the rate of social play they participated in, and the more aggressive play they engaged in. Immatures with high-ranking mothers initiated more social play among each other. A similar pattern of playmates was found among juveniles/adolescents with middle-ranking and low-ranking mothers. We also found that immatures preferred immatures with higher-ranking mothers as grooming mates and initiated more grooming with immatures with higher-ranking mothers than with those with lower-ranking mothers. Our study suggests that females’ social ranks affect the development of social relationships among their immature offspring. In despotic nonhuman primates, this indicates that the mother’s dominance hierarchy would directly or indirectly influence the processes of participating in social interactions and choosing partnerships among immature individuals with age (i.e., infancy, juvenile, and adolescent periods).

Leadership is a key issue in the study of collective behavior in social animals. Affiliation–leadership models predict that dyadic partner preferences based on grooming relationships or alliance formation positively affect an individual's decision to follow or support a conspecific. In the case of many primate species, females without young infants are attracted to mother–infant dyads. However, the effects of mother–infant–female associations on affiliation–leadership models remain less clear. In free-ranging Tibetan macaques Macaca thibetana , we used social network analysis to examine the importance of "mother-infant-adult female" social bridging events as a predictor of who leads and who follows during group movement. Social bridging is a common behavior in Tibetan macaques and occurs when 2 adults, generally females, engage in coordinated infant handling. Using eigenvector centrality coefficients of social bridging as a measure of social affiliation, we found that among lactating females, initiating bridging behavior with another female played a significant role in leadership success, with the assisting female following the mother during group movement. Among nonlactating females, this was not the case. Our results indicate that infant attraction can be a strong trigger in collective action and directing group movement in Tibetan macaques and provides benefits to mothers who require helpers and social support in order to ensure the safety of their infants. Our study provides new insights into the importance of the third-party effect in rethinking affiliation–leadership models in group-living animals. [ABSTRACT FROM AUTHOR]

Theories proposed to explain social play have centered on its function in establishing social relationships critical for adulthood, its function in developing motor skills needed to survive, and promoting cognitive development and social learning. In this study, we compared variations in social play among infant and juvenile male and female Macaca thibetana. Given that this species is characterized by female philopatry and male dispersal, we hypothesized that immature females use social play as a mechanism to develop bonds that persist through adulthood whereas immature males use play to develop social skills needed to successfully enter new groups. The results indicated that social play steadily increased during the infant period and peaked at approximately 12 months of age. There were no significant differences in the frequency or types of social play exhibited between infant males and infant females. During the juvenile period, however, social play was found to decrease with age, with males engaging in social play more frequently than juvenile females. Moreover, whereas juvenile males engaged in more aggressive forms of play, juvenile females engaged in more affiliative forms of play. In addition, juvenile females engaged in higher rates of grooming than juvenile males. These results provide evidence of sex-specific differences and imply the functional variation of social play in Tibetan macaques, with immature males using social play to develop skills needed to enter and enhanced their dominance rank in a new social group and immature females using social play to develop long-term same-sex social bonds in their natal group.

The analysis of grooming networks is a powerful tool to examine individual social and sexual relationships and how these relationships change over time. In this study, we investigated the seasonal dynamics of intra- and intersexual social relationships in Tibetan macaques (Macaca thibetana) based on grooming interactions. Similar to other female philopatric and male dispersal primates, female Tibetan macaques form the core of the social group with higher values of centralities, compared to the males who tend to be distributed on the periphery of the grooming network. The results of this study indicate that females formed stable clusters with maternal kin-related female partners both during the mating and non-mating season. Males were not included in the females' clusters during the mating season, however, during the non-mating season high-ranking males joined females to form loosely connected clusters. Male–female clustering was associated with the frequency of grooming (bouts per hour) rather than grooming duration (bout length). Our results illustrate that Tibetan macaque social networks fluctuate in response to reproductive seasonality and appear to play a role in mating choice and male reproductive success. Moreover, our results indicate that the frequency of grooming interactions might be more effective than the duration of grooming interactions in establishing cluster pattern on group level. It appears that changes in male mating strategies may drive these shifting social relationships and networks. Future studies on Tibetan macaques will need to investigate the degree to which changes in male grooming strategies directly correlate with male reproductive success. [ABSTRACT FROM AUTHOR]

In some non-human primates, infants function as a social tool that can bridge relationships among group members. Infants are a desired commodity for group members, and mothers control access to them. The biological market theory suggests that grooming is widespread and represents a commodity that can be exchanged for infant handling. As a limited resource, however, the extent to which infants are interchanged between mothers (females with an infant) and non-mothers (potential handlers, females without an infant) remains unclear. In this study, we collected behavioral data to investigate the relationship between grooming and infant handling in free-ranging Tibetan macaques (Macaca thibetana) at Mt. Huangshan, China. Our results showed that females with infants received more grooming than females without infants. After her infant was handled, mother females received more grooming than they did during daily grooming interactions. However, with the increasing number of infants within the social group, both the grooming that mothers received and the grooming that non-mothers invested for handling infants decreased. We also found that non-mothers invested more time in grooming to gain access to younger infants than older infants. Our results provide evidence that infants are social commodities for both mother and non-mother females. Mothers use infants for obtain grooming and non-mothers use grooming to gain access to infants. The current study implies a bidirectional and complex interchange pattern between grooming and infant handling to compensate for the dyadic grooming disparity in non-human primates. [ABSTRACT FROM AUTHOR]

Social organisms make collective decisions during group movement, thereby remaining cohesive and providing the ecological and evolutionary benefits of sociality. The ability for groups to make successful collective decisions is dependent on relationships between leaders and followers. We investigated how consistent followers (a fan structure) facilitated successful group movement in a group of Tibetan macaques, Macaca thibetana , at Mt. Huangshan in Anhui, China. We used structural equation modelling to determine the relative influences of sex, age, number of maternal familial connections within the group, dominance and social network centrality on the number of fans that an individual had and the number of other group members that an individual was a fan of (fandom). Our structural equation modelling revealed that dominant females had more fans, while younger, dominant individuals with more familial connections were fans of more individuals. Fans and fandom were most strongly influenced by dominance, displaying a strong network of females occupying top positions in the dominance hierarchy who consistently followed each other. In addition, we examined the relationship between fan structure and movement speed and success. Using regression, we found a positive relationship between fans and speed and a negative correlation between fans and number of unsuccessful movements, suggesting a link between the social connections maintained in a movement and the speed of the movement. Dominant females with more fans initiated slower movements, perhaps because the complex fan structure slowed the joining process. However, individuals with more fans led fewer unsuccessful movements, suggesting a relationship between fans and initiation success. Our findings show a network of social relationships within Tibetan macaque groups that are used during movement organization to maintain cohesion and mediate the benefits of sociality. Highlights • We studied Tibetan macaque decision making during collective movement. • Dominant females had the most consistent followers during movement. • Dominant, younger individuals with more kin consistently followed more individuals. • Individuals with more consistent followers led slower movements. • Individuals with more consistent followers had fewer unsuccessful movement initiations. [ABSTRACT FROM AUTHOR]

Seventeen full‐length Math‐DQB1 alleles were characterized in Tibetan macaques. [ABSTRACT FROM AUTHOR]

Macaca thibetana is an endemic species to China that is listed as near threatened in the IUCN Red Data Book. The species has previously been used in animal models for biomedical research. Due to anthropogenic impacts, the wild populations of M. thibetana have dramatically declined in recent years, which has resulted in low genetic diversity. Insufficient molecular markers have hindered the effective conservation and management of this species. In the present study, ten contig sequences containing 29 novel polymorphic SNPs were discovered using 40 samples as templates for PCR validation. The minor allele frequency ranged from 0.100 to 0.488, and the observed and expected heterozygosities ranged from 0 to 0.600 and 0.182 to 0.506, respectively. The FIS ranged from − 0.203 to 1.000. Among these SNPs, four loci showed significant departures from the Hardy–Weinberg equilibrium (p < 0.05). The novel polymorphic SNPs will help elucidate the population structure and conservation genetics of this precious species. [ABSTRACT FROM AUTHOR]

Recent studies highlight that the gut mycobiota play essential roles in mammalian metabolic and immune systems, but to date we lack information on the forces that naturally shape the gut mycobiota of wild primates. To investigate the contributions of host and environmental factors in the taxonomic variation of the gut mycobiota, we examined the effects of age, sex, and season on the fecal mycobiota in wild‐living Tibetan macaques (Macaca thibetana). Using next generation sequencing and a longitudinal set of fecal samples collected over 1 year, we identified a set of core fungal taxa present in the Tibetan macaque's fecal samples. The predominant genera Aspergillus and Penicillium, which promote the digestion of cellulose and hemicellulose in herbivorous mammals, were detected in this study. Similar to humans, we found age and sex effects on the macaques’ fecal mycobiota. We also found that both fecal fungal composition and diversity (alpha and beta diversity) varied significantly by season. In particular, the Penicillium enriched mycobiota in summer samples may aid in the digestion of cellulose and hemicellulose present in mature leaves. The high alpha diversity detected in Tibetan macaques’ winter fecal samples may facilitate a diet rich in fiber ingested during this season. We propose that the gut mycobiota play an important role in the macaques’ ability to adapt to seasonal fluctuations in food availability and nutrient content. [ABSTRACT FROM AUTHOR]

Progesterone, a 'female' hormone, modulates sexual behaviors in male mammals. This modulation is well documented in laboratory animals, but it is as yet unknown whether progesterone is associated with testosterone and/or sexual behaviors in primates living in their natural environments. In this study, we collected a total of 426 fecal samples and approximately 453 h of behavioral data from five male Tibetan macaques ( Macaca thibetana) to study relationships between males' progesterone and testosterone levels and sexual behaviors. Our results showed a negative correlation between fecal testosterone and progesterone levels. Both hormones seasonally varied. For three of the five subjects, we also found that copulatory and sexually motivated behaviors were negatively correlated with fecal progesterone levels. While not significant for the other two males, this study provides insight into the relationship between progesterone and the sexual behaviors of male primates living in a natural environment. [ABSTRACT FROM AUTHOR]

Background Pig-to-nonhuman primate orthotopic liver xenotransplantation is often accompanied by thrombocytopenia and coagulation disorders. Furthermore, the release of cytokines can trigger cascade reactions of coagulation and immune attacks within transplant recipients. To better elucidate the process of inflammation in liver xenograft recipients, we utilized a modified heterotopic auxiliary liver xenotransplantation model for xeno-immunological research. We studied the cytokine profiles and the relationship between cytokine levels and xenograft function after liver xenotransplantation. Methods Appropriate donor and recipient matches were screened using complement-dependent cytotoxicity assays. Donor liver grafts from α1,3-galactosyltransferase gene-knockout ( GTKO) pigs or GTKO pigs additionally transgenic for human CD47 ( GTKO/ CD47) were transplanted into Tibetan macaques via two different heterotrophic auxiliary liver xenotransplantation procedures. The cytokine profiles, hepatic function, and coagulation parameters were monitored during the clinical course of xenotransplantation. Results Xenograft blood flow was stable in recipients after heterotopic auxiliary transplantation. A Doppler examination indicated that the blood flow speed was faster in the hepatic artery ( HA) and hepatic vein ( HV) of xenografts subjected to the modified Sur II ( HA-abdominal aorta+ HV-inferior vena cava) procedure than in those subjected to our previously reported Sur I ( HA-splenic artery+ HV-left renal vein) procedure. Tibetan macaques receiving liver xenografts did not exhibit severe coagulation disorders or immune rejection. Although the recipients did suffer from a rapid loss of platelets, this loss was mild. In blood samples dynamically collected after xenotransplantation (post-Tx), dramatic increases in the levels of monocyte chemoattractant protein 1, interleukin ( IL)-8, granulocyte-macrophage colony-stimulating factor, IL-6, and interferon gamma-induced protein 10 were observed at 1 hour post-Tx, even under immunosuppression. We further confirmed that the elevation in individual cytokine levels was correlated with the onset of graft damage. Finally, the release of cytokines might contribute to leukocyte infiltration in the xenografts. Conclusion Here, we established a modified auxiliary liver xenotransplantation model resulting in near-normal hepatic function. Inflammatory cytokines might contribute to early damage in liver xenografts. Controlling the systemic inflammatory response of recipients might prevent early post-Tx graft dysfunction. [ABSTRACT FROM AUTHOR]

Objective To investigate the changes in the expression levels of scavenger receptor class B member 1 (SCARB1) in the liver tissues before and after liver xenotransplantation and analyze the relationship between the variations in the SCARB1 expression and coagulation regulating dysfunction in the recipients. Methods The Wuzhishan miniature pig with α-1, 3-galactosyltransferase gene-knockout(GTKO) was utilized as the donor and Macaca thibetana was chosen as the recipient. Heterotopic auxiliary liver xenotransplantation models were established. The liver tissue specimen was collected before and after liver xenotransplantation. Primary hepatocytes were extracted from the pig using collagenase digestion method. Human peripheral blood mononuclear cells were obtained by immunomagnetic bead soiling. These two types of cells were co-cultured and supplemented with human plasma to establish cell models with coagulation regulating dysfunction following liver xenotransplantation. Quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) and Western blot were performed to quantitatively measure and statistically compared the expression levels of messenger ribonucleic acid (mRNA) and protein of SCARB1 in the tissue and cell samples. At the cellular level, the expression of SCARB1 was interfered by lentiviral vector. The coagulation time was detected to validate the effect upon coagulation function. Results The expression levels of SCARB1 mRNA and protein were significantly down-regulated after liver xenotransplantation (both P<0.05). In the cell models, the expression levels of SCARB1 mRNA and protein in the porcine hepatocytes co-cultured with human monocytes were significantly down-regulated compared with those in porcine hepatocytes without intervention (both P<0.05). Compared with the non-intervention group, the coagulation time was significantly prolonged after the expression of SCARB1 was interfered by lentiviral vector (P<0.05). Conclusions The down-regulated expression of SCARB1 in the liver graft is one of the main causes of mediating coagulation regulating dysfunction. Intervention of SCARB1 expression contributes to resolve the coagulation regulating dysfunction in the recipients after liver xenotransplantation. [ABSTRACT FROM AUTHOR]

Fifteen Math‐DMA and 16 Math‐DMB novel alleles of Tibetan macaques were identified. [ABSTRACT FROM AUTHOR]

Though females are generally more selective in mate choice, males may also benefit from mate choice if male reproductive success is limited by factors other than simply the number of female mates, and if females differ in short-term reproductive potential. We studied male mate choice in a free-ranging troop of Tibetan macaques Macaca thibetana at Mt. Huangshan, China, from August 2007 to April 2008. We employed focal animal sampling and all occurrence sampling to record sexual related behaviors. Eight adult females were divided into three female quality categories according to the females’ age, rank and parity. Using male mating effort as a proxy for male mate choice, we found that males do distinguish female quality and show time-variant mating strategies. Specifically, females with dominant rank, high fecundity, and middle age attracted significantly more males. Our results suggest that female short-term reproductive potential appears to be an important variable in determining male mating effort. Male Tibetan macaques do exercise mate choice for higher quality females as well as reduce useless reproductive cost, which is consistent with the direct benefits theory of mate choice [Current Zoology 56 (2): 213–221, 2010].

Vocal repertoires are basic and essential components for describing vocal communication in animals. Studying the entire suite of vocal signals aids investigations on the variation of acoustic structure across social contexts, comparisons on the complexity of communication systems across taxa, and in exploration of the evolutionary origins of species-specific vocalizations. Here, we describe the vocal repertoire of the largest species in the macaque genus, Macaca thibetana. We extracted thirty acoustic parameters from call recordings. Post hoc validation through quantitative analyses of the a priori repertoire classified eleven call types: coo, squawk, squeal, noisy scream, growl, bark, compound squeak, leap coo, weeping, modulated tonal scream, and pant. In comparison to the rest of the genus, Tibetan macaques uttered a wider array of vocalizations in the context of copulations. Previous reports did not include modulated tonal screams and pants during harassment of copulatory dyads. Furthermore, in comparison to the rest of the genus, Tibetan macaque females emit acoustically distinct copulation calls. The vocal repertoire of Tibetan macaques contributes to the literature on the emergence of species-specific calls in the genus Macaca with potential insights from social, reproductive, and ecological comparisons across species. Am. J. Primatol. 78:937-949, 2016. © 2016 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Research on leadership is a critical step for understanding collective decision making. However, only 4 of the 22 extant macaque species have been examined for the impact of social rank and affiliation on the initiation of collective movement. It is far from clear whether such impact exists and, if so, how it works among other macaques. To answer these questions, we investigated free-ranging, Tibetan macaques' ( Macaca thibetana) group departures from a provisioning area and tested two alternative hypotheses: personal versus distributed leadership. Personal leadership predicts that a single, highest ranking individual initiates the most group movements, whereas distributed leadership predicts that different members lead the group on different occasions and affiliative individuals have more initiations. We recorded how often and how successfully adults initiated group movements from a provisioning area into the forest, and related these variables to the duration of interindividual proximity and grooming time in the forest. All adults initiated group movements, but did so variably. Social rank was related neither to the number of successful initiations nor to the success ratio of initiations. By contrast, eigenvector centrality based on proximity relations was positively correlated with the number and ratio of successful initiations. Moreover, successful initiations were positively correlated with social grooming. Overall, Tibetan macaques showed a pattern of distributed leadership. Our study demonstrated the relationship between social affiliation and individual leadership in a macaque society. Am. J. Primatol. 78:816-824, 2016. © 2016 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

We have recently demonstrated the potentially virulent species Entamoeba nuttalli as one of the highly prevalent parasites in rhesus macaques ( Macaca mulatta ) in Mount Long-hu and Gui-yang in China. Tibetan macaque ( Macaca thibetana ) is a unique species living in China. To evaluate the prevalence of Entamoeba species in wild Tibetan macaques, we obtained 89 stool samples in Mount E-mei of Si-chuan Province in China. PCR analysis detected E. nuttalli , Entamoeba coli , and Entamoeba polecki ST2 in 17%, 42%, and 66% of the samples, respectively, whereas Entamoeba histolytica and Entamoeba dispar were undetected. This study is the first to report on the detection of E. nuttalli from Tibetan macaques. Six E. nuttalli isolates were obtained, 18S rRNA gene and six tRNA-linked short tandem repeat (STR) loci of the isolates were sequenced. The Mantel test results gave an r value of 0.97 of relationships between geographical distance and genetic diversity of Chinese E. nuttalli populations, indicating a significant isolation-by-distance effect in Chinese E. nuttalli according to the tRNA-STR loci sequences. Structural analysis of E. nuttalli isolates based on tRNA-linked STR loci demonstrated three Chinese E. nuttalli populations with their respective features, but the Gui-yang population was located in the middle. In the distance-based NJ tree, E. nuttalli isolates were divided into five different branches, and E-mei isolates were attributed to an independent branch to distinguish them from Gui-yang and Long-hu isolates. Genetic analysis in this study provided clues of the genetic differences between E. nuttalli isolates from Tibetan macaques and rhesus macaques in China. [ABSTRACT FROM AUTHOR]

We report here the identification of eight new Math‐DPB1 alleles in the Tibetan macaques. [ABSTRACT FROM AUTHOR]

Although male testosterone levels are thought to be linked with the mating system, ecological and social factors complicate the big picture of the function of testosterone in wild nonhuman primates. We examined testosterone correlates with rank and copulatory behavior in male Tibetan macaques (Macaca thibetana) at Mt. Huangshan, China. A total of 426 fecal samples and approximately 453h of behavioral data were collected on five adult males from October 2005 to September 2006. Copulatory behaviors were significantly different between high and low ranking males in the mating season, but not during the non-mating season. No significant correlation between testosterone levels and a male's David's score indicated that testosterone was independent of social rank. Also, copulatory behaviors were positively correlated with fecal testosterone levels in both seasons, regardless of social rank. The present study represents a preliminary assessment of the relationship between testosterone level, rank, and copulatory behavior in a wild environment. The results enrich the picture of testosterone, rank, and copulatory relationships in non-human primates, and may also provide insight into what mechanisms link physiological factors to male reproductive success in natural circumstances. [ABSTRACT FROM AUTHOR]

Collective behavior has recently attracted a great deal of interest in both natural and social sciences. While the role of leadership has been closely scrutinized, the rules used by joiners in collective decision making have received far less attention. Two main hypotheses have been proposed concerning these rules: mimetism and quorum. Mimetism predicts that individuals are increasingly likely to join collective behavior as the number of participants increases. It can be further divided into selective mimetism, where relationships among the participants affect the process, and anonymous mimetism, where no such effect exists. Quorum predicts that a collective behavior occurs when the number of participants reaches a threshold. To probe into which rule is used in collective decision making, we conducted a study on the joining process in a group of free-ranging Tibetan macaques (Macaca thibetana) in Huangshan, China using a combination of all-occurrence and focal animal sampling methods. Our results show that the earlier individuals joined movements, the more central a role they occupied among the joining network. We also found that when less than three adults participated in the first five minutes of the joining process, no entire group movement occurred subsequently. When the number of these early joiners ranged from three to six, selective mimetism was used. This means higher rank or closer social affiliation of early joiners could be among the factors of deciding whether to participate in movements by group members. When the number of early joiners reached or exceeded seven, which was the simple majority of the group studied, entire group movement always occurred, meaning that the quorum rule was used. Putting together, Macaca thibetana used a combination of selective mimetism and quorum, and early joiners played a key role in deciding which rule should be used. [ABSTRACT FROM AUTHOR]

Young Alu elements that have been inserted recently in macaque genomes are still polymorphic for insertion presence/absence at the individual and population levels. They have been considered as a powerful tool in population genetics of primates. Combining a computational approach and a PCR display method based on primers of OWM-specific Alu subfamilies, in the present study, we identified and characterized 26 novel Alu insertions that are polymorphic in the Tibetan macaque ( Macaca thibetana). Along with 20 previously reported loci, a total of 96 Alu insertions were found to be present in the Tibetan macaque but absent in rhesus macaques ( Macaca mulatta) as validated by computational methods. After PCR verification, 27.1 % (26/96) of the analyzed insertions were confirmed to be heterozygous among Tibetan macaque individuals. These 26 newly identified loci were further genotyped in 41 individuals from two Tibetan macaque populations. The average allele frequencies across the 26 loci varied from 2.4 to 48.8 % in the two populations. The average expected heterozygosity per locus ranged from 25.3 to 50.6 %. The results indicate that the combination of a computational approach and a PCR display method is an efficient way to identify young polymorphic Alu insertions in macaques, and the newly identified polymorphic loci represent valuable genetic markers for the study of Tibetan macaque population genetics in the future. [ABSTRACT FROM AUTHOR]

To further the potential for applied personality studies, we present a methodology for assessing personality in nonhuman animals without a priori assumptions, using behavioral measures to discriminate personality survey results. Our study group consisted of 12 free-ranging, provisioned, adult Tibetan macaques Macaca thibetana at the Valley of the Wild Monkeys, China. We asked familiar Chinese park guards and scientists to rate each of the 12 macaques using 27-item personality surveys. We also recorded behavioral observations (> 100 hrs) from August-September, 2012. The personality surveys showed reliability in 22 of the items that were then utilized in a principal component analysis that revealed five components: Insecurity, Reactivity, Boldness, Sociability, and Leadership. Prior personality research on Macaca show comparable components. In order to determine which behaviors would best predict those five personality components, we conducted discriminant analyses using behavioral measures as predictors. We found that behavioral measures of avoidance, lunging, fear-grinning, self-directed behaviors, touching, proximity and chasing could significantly predict personality component scores in certain situations. Finally, we analyzed the effects of situation (provisioning and tourists) and found situation influenced proximity and rates of avoidance and self-directed behaviors. Wider implementation of this methodology may permit long-term analysis of personality using behavioral proxies for established personality traits, in particular on research investigating the effects of tourism and provisioning on personality. [ABSTRACT FROM AUTHOR]

Background Limited physiological data for Tibetan macaques are available at present. This study will provide more rationale for evaluating this species. Methods Thirty-seven Tibetan macaques (15 males and 22 females) were used in this study. Somatometric measurements, clinical chemistry and hematology parameters, insulin, and C-peptide were analyzed. Results Females had higher values of waist and waist hip ratio ( WHR) than males in somatometric measurements. There were no significant differences between the two genders in hematology. Significant differences between males and females were only found for aspartate aminotransferase ( AST) and alanine aminotransferase ( ALT) in biochemistry testing. In addition, females had higher fasting insulin and C-peptide than males. There was a strongly positive correlation between age and some somatometric parameters. Conclusions These physiological data will provide veterinarians and researchers with baseline values to evaluate experimental results using Tibetan macaques. [ABSTRACT FROM AUTHOR]

In several primate species, adult males are reported to compete for access to reproductive partners as well as forming affiliative and cohesive social bonds based on the exchange of goods or services. We hypothesized that among a broad set of fitness-maximizing strategies, grooming can be used by individual adult males to enhance social relationships through reciprocity and/or through the interchange of grooming for a different but equivalent good or service. We used focal animal sampling and continuously recorded dyadic grooming and agonistic interactions to test a series of predictions regarding male social interactions in a free-ranging group of Tibetan macaques ( Macaca thibetana) at Huangshan, China. During the non-mating season or between males of similar rank throughout the year, grooming effort given was matched by grooming effort received. However, lower ranking males groomed higher ranking males at a greater rate and/or for a longer duration during both the mating and non-mating periods. We found that higher ranking males directed less aggression towards males with whom they formed a frequent grooming partnership, indicating that grooming received was interchanged for increased social tolerance. These data suggest that individual male Tibetan macaques employ alternative social strategies associated with grooming reciprocity or interchange depending on dominance rank and rates of aggression, and highlight the importance of both biological markets and grooming reciprocity as behavioral mechanisms used by resident adult males to form and maintain affiliative social bonds. Am. J. Primatol. 75:1009-1020, 2013. © 2013 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Tibetan macaque ( Macaca thibetana), an endangered primate species endemic to China, have been used as experimental animal model for various human diseases. Major histocompatibility complex ( MHC) genes play a crucial role in the susceptibility and/or resistance to many human diseases, but little is known about Tibetan macaques. To gain an insight into the MHC background and to facilitate the experimental use of Tibetan macaques, the second exon of Mhc- DQB1 gene was sequenced in a cohort of wild Tibetan macaques living in the Sichuan province of China. A total of 23 MhcMath-DQB1 alleles were identified for the first time, illustrating a marked allelic polymorphism at the DQB1 locus for these macaques. Most of the sequences (74%) observed in this study belong to DQB1*06 (9 alleles) and DQB1*18 (8 alleles) lineages, and the rest (26%) belong to DQB1*15 (3 alleles) and DQB1*17 (3 alleles) lineages. The most frequent alleles detected among these macaques were MhcMath-DQB1*15:02:02 (17.9%), followed by Math- DQB1*06:06, 17:03 and 18:01, which were detected in 9 (16.1%) of the monkeys, respectively. Non-synonymous substitutions occurred at a significantly higher frequency than synonymous substitutions in the peptide-binding region, suggesting balancing selection for maintaining polymorphisms at the MHC class II DQB1 locus. Phylogenetic analyses confirms the trans-species model of evolution of the Mhc-DQB1 genes in non-human primates, and in particular, the extensive allele sharing is observed between Tibetan and other macaque species. [ABSTRACT FROM AUTHOR]

Tibetan macaque ( Macaca thibetana) is a threatened primate species endemic to China. Population genetic and phylogenetic analyses were conducted in 66 Tibetan individuals from Sichuan (SC), Huangshan (HS), and Fujian (FJ) based on a 477-bp fragment of mitochondrial DNA control region. Four new haplotypes were defined, and a relatively high level of genetic diversity was first observed in FJ populations (Hd = 0.7661). Notably, a continuous approximately 10 bp-fragment deletion was observed near the 5′ end of the mtDNA control region of both HS and FJ populations when compared with that of SC population, and a sharing haplotype was found between the two populations, revealing a closer genetic relationship. However, significant genetic differentiation ( FST = 0.8700) and more poor gene exchange (Nm < 1) had occurred among three populations. This study mainly provide a further insight into the genetic relationship between HS and FJ Tibetan macaque populations, but it may be necessary to carry out further study with extra samples from other locations in the geographic coverage of the two subspecies ( M. thibetana pullus and M. thibetana huangshanensis). [ABSTRACT FROM AUTHOR]

Tibetan macaque ( Macaca thibetana), an endangered species endemic to China, is categorized as a Category II species under the Chinese Wild Animal Protection Law and listed in Appendix II of the Convention on International Trade in Endangered Species. To further assess genetic diversity and population structure within this species, we sequenced 477 bp of mitochondrial DNA control region in 30 Tibetan macaques from the Guizhou (GZ) and Yunnan (YN) of China and conducted population genetic analysis, along with 15 previously described haplotype sequences representing 55 individuals from Sichuan (SC) and Anhui (AH). 87 polymorphic sites were detected in the alignment of 45 sequences and defined 22 haplotypes, of which 9 were newly identified. Haplotype diversity ( h), nucleotide diversity ( π) and average number of nucleotide differences ( K) is 0.911 ± 0.015, 0.06090 ± 0.00126 and 28.32, respectively, indicating higher genetic diversity in the whole Tibetan macaque population. Analysis of molecular variance (AMOVA) partitioned the total variation into 83.63 % among populations and 16.37 % within populations, revealing that variations occured among populations mainly. Further analysis demonstrated that significant genetic differentiation ( Fst = 0.83628, P < 0.01) and poor gene flow ( Nm < 1) had occurred among these four populations. On the phylogenetic tree and haplotype network plot, 22 haplotypes cluster together according to their geographical origins, exhibiting an obvious phylogeographic pattern. We speculate that the significant genetic differentiation among these macaque populations might result from long-term geographic barrier and human activity. In particular, Yangtze River probably play a vital role in population differentiation of Tibetan macaques. [ABSTRACT FROM AUTHOR]

Cryptic and endangered fauna, including many primate taxa, pose challenges for noninvasive collection of biomaterials. As a result, application of noninvasive genotyping to primates has been limited to the use of samples such as feces and hair for the extraction of PCR-amplifiable DNA. We present a method for noninvasive collection of saliva from habituated, free-ranging monkeys. The method utilizes a low-cost apparatus that controls for contamination and is usable with individual, free-ranging primates. Saliva samples were collected from 18 individuals in a population of Tibetan macaques ( Macaca thibetana) in the Valley of Wild Monkeys in Huangshan, People's Republic of China. DNA was extracted from these samples and PCR-amplified for both mitochondrial and nuclear genes, Cytochrome B and MHC- DR Beta 1, respectively. These results indicate this is an effective technique for the noninvasive collection of saliva across age and sex class, and dominance rank in a free-ranging, terrestrial primate species. This device could have wide application for obtaining high-quality saliva samples from free-ranging primate populations for use in epidemiological studies, hormonal analyses of HPA axis function, pathogen screening, noninvasive genotyping, and behavioral genetics. Am. J. Primatol. 74:1064-1070, 2012. © 2012 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Grooming among nonhuman primates is widespread and may represent an important service commodity that is exchanged within a biological marketplace. In this study, using focal animal sampling methods, we recorded grooming relationships among 12 adult females in a free-ranging group of Tibetan macaques ( Macaca thibetana) at Huangshan, China, to determine the influence of rank and kinship on grooming relationships, and whether females act as reciprocal traders (exchange grooming received for grooming given) or interchange traders (interchange grooming for social tolerance or other commodities). The results showed that: (1) grooming given was positively correlated with grooming received; (2) kinship did not exert a significant influence on grooming reciprocity; and (3) grooming reciprocity occurred principally between individuals of adjacent rank; however, when females of different rank groomed, females tended to groom up the hierarchy (lower ranking individuals groomed higher ranking individuals more than vice versa). Our results support the contention that both grooming reciprocity and the interchange of grooming for tolerance represent important social tactics used by female Tibetan macaques. Am. J. Primatol. 74:569-579, 2012. © 2012 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Biological markets principles offer testable hypotheses to explain variation in grooming exchange patterns among nonhuman primates. They predict that when within-group contest competition (WGC) is high and dominance hierarchies steep, grooming interchange with other 'commodity' behaviors (such as agonistic support) should prevail. In contrast, when WGC is low and gradients shallow, market theory predicts that grooming reciprocity should prevail. We tested these predictions in a wild, provisioned Tibetan macaque ( Macaca thibetana) group across six time periods during which the group had been subjected to varying degrees of range restriction. Data on female-female aggression, grooming, and support were collected using all-occurrences and focal animal sampling techniques, and analyzed using ANCOVA methods and correlation analyses. We found that hierarchical steepness varied significantly across periods, but did not correlate with two indirect indicators of WGC (group size and range restriction) in predicted directions. Contrary to expectations, we found a negative correlation between steepness and group size, perhaps because the responses of group members to external risks (i.e. prolonged and unavoidable exposure to humans) may have overshadowed the effects of WGC. As predicted, grooming reciprocity was significant in each period and negatively correlated with steepness, even after we controlled group size, kinship, rank differences, and proximity. In contrast, there was no evidence for grooming interchange with agonistic support or for a positive relationship between interchange and steepness. We hypothesize that stressful conditions and/or the presence of stable hierarchies during each period may have led to a greater market demand for grooming than support. We suggest that future studies testing these predictions consider more direct measures of WGC and commodities in addition to support, such as feeding tolerance and access to infants. Am. J. Primatol. 73:1269-1279, 2011. © 2011 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Twenty-one microsatellite loci were isolated from AC-enriched library of Tibetan macaque ( Macaca thibetana). The number of alleles at the 21 microsatellite loci ranged from 8 to 15, with an average of 12.2 per locus. Polymorphism information content (PIC) ranged from 0.805 to 0.910 with an average of 0.873. The observed and expected heterozygosities ranged from 0.208 to 0.792 and from 0.843 to 0.938, respectively. These microsatellite loci will be useful for future studies that relate to the genetic diversity and population structure of Tibetan macaque. [ABSTRACT FROM AUTHOR]

The purpose of this study was to determine the taxonomic status of an unidentified enigmatic macaque seen by scientists since the late 1990s in Arunachal Pradesh, India. We surveyed 49 troops of enigmatic macaques in four districts of Arunachal Pradesh. The population studied is from the macaque sinica-group as defined by the reproductive organs. The main species-separating trait in the sinica-group is tail length to head and body length ratio that decreases with latitude and elevation. We gathered data on morphology, pelage descriptions, tail to head and body ratios and tail to hind foot ratios from photos and live animals (43 individuals from 36 areas) within the range of and between the two subspecies of the Assamese macaque ( Macaca assamensis). We compared the data to six western Assamese macaques and studies of Assamese macaques and related species. We found great variability in tail length, pelage color, facial skin color, and facial and hair patterns. The tail/head-body and tail/foot ratios, although varied, supported the hypothesis that these enigmatic forms were part of a population of Assamese macaques found in the gap between the two subspecies ranges and were not a new species as described earlier. Instead, we found evidence that darker pelage, larger body size, and shorter tails occur at higher elevations and latitudes similar to the general trend in the sinica-group's adaptations to colder climates. Thus, the population may be important for its variation, throwing light on the speciation process and how the northern species of Tibetan macaques evolved from an ancestor similar to the Assamese macaques as adaptations to a colder climate. Am. J. Primatol. 73:458-473, 2011. © 2011 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR]