Is Yuan in China's Three Gorges a Gibbon or a Langur?

Clarifying the scientific identity of ancient biological names in historical archives is essential to understand traditional knowledge and literary metaphors of animals in human culture. Adopting a cross-disciplinary (Primatology, Linguistics, Historiography, Historical Sociology) analysis, we developed a theoretical framework for studies of the scientific identity of Chinese primate traditional names (e.g., Yuan ) throughout history, and interpret the historical evolution of the understanding of the Chinese word Yuan. Presently, the Chinese generally understand Yuan to be a gibbon (or "ape" in a broader sense), but this statement has many contradictions with the understanding of the word in relevant historical discourse. We review and comment on key evidence to support the traditional understanding of Yuan as a gibbon (Hylobatidae) and clarify the historical and current thought concerning Yuan. We find that the referent of the word Yuan has changed from "François' langur (Trachypithecus francoisi) with long limbs" to the "long-armed ape or gibbon" known today through two major changes in the idea of Yuan. One transformation in the conceptualization of Yuan took place during the Tang-Song period, with the other beginning at the end of the nineteenth century and ending in the 1950s. An interaction between the conceptualization of animals and power (e.g., political opportunity; cultural movement toward learning western sciences in the semi-colonial era) played an important role in these two diachronic changes to the idea of Yuan. In contrast to the clear linear relation between a species and its Latin name, our study indicates that one traditional name can represent varying animal species in China. Our findings exemplify the implications of the sociocultural and linguistic basis for the species identification of primate names found in historical discourse for historical zoogeography, our understanding of the intricate cultural and religious connections between humans and primates, and efforts to decolonize primatology. Supplementary Information: The online version contains supplementary material available at 10.1007/s10764-022-00302-1.

Allometric escape and acoustic signal features facilitate high-frequency communication in an endemic Chinese primate.

The principle of acoustic allometry-the larger the animal, the lower its calls' fundamental frequency-is generally observed across terrestrial mammals. Moreover, according to the Acoustic Adaptation Hypothesis, open habitats favor the propagation of high-frequency calls compared to habitats with complex vegetational structures. We carried out playback experiments in which the calls of the Guizhou snub-nosed monkey (Rhinopithecus brelichi) were used as stimuli in sound attenuation and degradation experiments to test the hypothesis that propagation of Guizhou snub-nosed monkey calls is favored above vs through the forest floor vegetation. We found that low-pitched Guizhou snub-nosed monkey vocalizations suffered less attenuation than its high-pitched calls. Guizhou snub-nosed monkeys were observed emitting high-pitched calls from 1.5 to 5.0 m above the ground. The use of high-pitched calls from these heights coupled with the concomitant behavior of moving about above the understory may provide a signal for receivers which maximizes potential transmission and efficacy. Our results support the Acoustic Adaptation Hypothesis and suggest that by uncoupling its vocal output from its size, this monkey can produce a high-pitched call with a broad spectral bandwidth, thereby increasing both its saliency and the frequency range over which the animal may more effectively communicate in its natural habitat.

Gut microbiota in wild and captive Guizhou snub-nosed monkeys, Rhinopithecus brelichi.

Many colobine species-including the endangered Guizhou snub-nosed monkey (Rhinopithecus brelichi) are difficult to maintain in captivity and frequently exhibit gastrointestinal (GI) problems. GI problems are commonly linked to alterations in the gut microbiota, which lead us to examine the gut microbial communities of wild and captive R. brelichi. We used high-throughput sequencing of the 16S rRNA gene to compare the gut microbiota of wild (N = 7) and captive (N = 8) R. brelichi. Wild monkeys exhibited increased gut microbial diversity based on the Chao1 but not Shannon diversity metric and greater relative abundances of bacteria in the Lachnospiraceae and Ruminococcaceae families. Microbes in these families digest complex plant materials and produce butyrate, a short chain fatty acid critical to colonocyte health. Captive monkeys had greater relative abundances of Prevotella and Bacteroides species, which degrade simple sugars and carbohydrates, like those present in fruits and cornmeal, two staples of the captive R. brelichi diet. Captive monkeys also had a greater abundance of Akkermansia species, a microbe that can thrive in the face of host malnutrition. Taken together, these findings suggest that poor health in captive R. brelichi may be linked to diet and an altered gut microbiota.

Diet Versus Phylogeny: a Comparison of Gut Microbiota in Captive Colobine Monkey Species.

Both diet and host phylogeny shape the gut microbial community, and separating out the effects of these variables can be challenging. In this study, high-throughput sequencing was used to evaluate the impact of diet and phylogeny on the gut microbiota of nine colobine monkey species (N = 64 individuals). Colobines are leaf-eating monkeys that fare poorly in captivity-often exhibiting gastrointestinal (GI) problems. This study included eight Asian colobines (Rhinopithecus brelichi, Rhinopithecus roxellana, Rhinopithecus bieti, Pygathrix nemaeus, Nasalis larvatus, Trachypithecus francoisi, Trachypithecus auratus, and Trachypithecus vetulus) and one African colobine (Colobus guereza). Monkeys were housed at five different captive institutes: Panxi Wildlife Rescue Center (Guizhou, China), Beijing Zoo, Beijing Zoo Breeding Center, Singapore Zoo, and Singapore Zoo Primate Conservation Breeding Center. Captive diets varied widely between institutions, but within an institution, all colobine monkey species were fed nearly identical or identical diets. In addition, four monkey species were present at multiple captive institutes. This allowed us to parse the effects of diet and phylogeny in these captive colobines. Gut microbial communities clustered weakly by host species and strongly by diet, and overall, colobine phylogenetic relationships were not reflected in gut microbiota analyses. Core microbiota analyses also identified several key taxa-including microbes within the Ruminococcaceae and Lachnospiraceae families-that were shared by over 90% of the monkeys in this study. Microbial species within these families include many butyrate producers that are important for GI health. These results highlight the importance of diet in captive colobines.

Effects of field conditions on fecal microbiota.

Gut microbiota can provide great insight into host health, and studies of the gut microbiota in wildlife are becoming more common. However, the effects of field conditions on gut microbial samples are unknown. This study addresses the following questions: 1) How do environmental factors such as sunlight and insect infestations affect fecal microbial DNA? 2) How does fecal microbial DNA change over time after defecation? 3) How does storage method affect microbial DNA? Fresh fecal samples were collected, pooled, and homogenized from a family group of 6 spider monkeys, Ateles geoffroyi. Samples were then aliquoted and subjected to varying light conditions (shade, sun), insect infestations (limited or not limited by netting over the sample), and sample preservation methods (FTA - Fast Technology for Analysis of nucleic acid - cards, or freezing in liquid nitrogen then storing at -20°C). Changes in the microbial communities under these conditions were assessed over 24h. Time and preservation method both effected fecal microbial community diversity and composition. The effect size of these variables was then assessed in relation to fecal microbial samples from 2 other primate species (Rhinopithecus bieti and R. brelichi) housed at different captive institutions. While the microbial community of each primate species was significantly different, the effects of time and preservation method still remained significant indicating that these effects are important considerations for fieldwork.

Into the night: camera traps reveal nocturnal activity in a presumptive diurnal primate, Rhinopithecus brelichi.

Most living primates exhibit a daytime or nighttime activity pattern. Strict diurnality is thought to be the rule among anthropoids except for owl monkeys. Here we report the diel activity pattern of an Asian colobine, the Guizhou snub-nosed monkey Rhinopithecus brelichi, based on a methodology that relied on using 24-h continuously operating camera traps. We conducted the study in Fanjingshan National Nature Reserve in Guizhou, China from March 22 to May 19 and from June 17 to October 14, 2011. After standardizing all time elements to a meridian-based time according to the geographic coordinates of the study site, we showed unequivocally that the monkeys, though predominantly diurnal, exhibited activity beyond daylight hours throughout the study. Specifically, their activity at night and during twilight periods suggests a complex interplay of behavioral adaptations, among others, to living in a temperate environment where day length and food resources fluctuate substantially across seasons. We contend that, under prevailing ecological conditions, so-called strictly diurnal primates may adjust their activity schedule opportunistically in order to increase energy intake. We also discuss the advantages of using camera traps in primate studies, and how the standardized use of meridian-based time by researchers would benefit comparisons of diel activity patterns among primates.

Altitudinal movements of Guizhou snub-nosed monkeys (Rhinopithecus brelichi) in Fanjingshan National Nature Reserve, China: implications for conservation management of a flagship species.

Primate movements can include a substantial altitudinal component, depending on the complexity of the landscape and the distribution of the inherent vegetation zones. We investigated altitudinal movements of Guizhou snub-nosed monkeys (Rhinopithecus brelichi) at Fanjingshan National Nature Reserve, China. The monkeys ranged at elevations between 1,350 and 1,870 m with an overall mean of 1,660 m. We did not find a significant difference in the mean elevations among seasons or evidence of winter migration to lower elevations. The monkeys exhibited a distinct daily altitudinal movement pattern that coincided with their activities. During the day, the monkeys consistently traveled from lower to higher elevations in the morning (98% of records) and then descended to lower elevations in the afternoon (96%). Hence, the mean elevation of night roosts was significantly lower (1,561 m) than those of feeding sites and day roosts (1,735 and 1,737 m, respectively). We suggest that this daily pattern of R. brelichi may reflect a trade-off between finding food and avoiding predation within the mixed evergreen and deciduous broadleaf vegetation zone at the study site, which may constitute the most important habitat for R. brelichi in the reserve.