Vocal signaling represents a primary mode of communication for most nonhuman primates. A quantitative description of the vocal repertoire is a critical step in in‐depth studies of the vocal communication of particular species, and provides the foundation for comparative studies to investigate the selective pressures in the evolution of vocal communication systems. The present study was the first attempt to establish the vocal repertoire of free‐ranging adult golden snub‐nosed monkeys (Rhinopithecus roxellana) based on quantitative methods. During 8 months in Shennongjia National Park, China, we digitally recorded the vocalizations of adult individuals from a provisioned, free‐ranging group of R. roxellana across a variety of social‐ecological contexts. We identified 18 call types, which were easily distinguishable by ear, visual inspection of spectrograms, and quantitative analysis of acoustic parameters measured from recording samples. We found a great sexual asymmetry in the vocal repertoire size (females produced many more call types than males), likely due to the sex differences in body size and social role. We found a variety of call types that occurred during various forms of agonistic and affiliative interactions at close range. We made inference about the functions of particular call types based on the contexts in which they were produced. Studies on the vocal communication in R. roxellana are particularly valuable since they provide a case about how nonhuman primates, inhabiting forest habitats and forming complex social systems, use their vocalizations to interact with their social and ecological environments.

The gastrointestinal tract of primates harbors a complex microbial community, playing an essential role in the degradation of otherwise indigestible structural carbohydrates. The phylogenetic and functional diversity of the bacterial community in the feces as a surrogate for the gastrointestinal tract of wild Sichuan snub-nosed monkeys (Rhinopithecus roxellana, N = 6) was characterized based on sequence analysis of 16S rRNA genes. A sex comparison was conducted, with a prior hypothesis that the abundances of the bacterial taxa and/or functional categories associated with energy and nutrient metabolism would be higher in adult females (N = 3) due to the higher reproductive costs compared to adult males (N = 3). Ten phyla were identified in all samples, among which Bacteroidetes and Firmicutes were the predominant. Included in the above two phyla, the members of Prevotellaceae (Prevotella in particular) and Ruminococcaceae were highly abundant, which are common bacteria in the gastrointestinal tract of primates and can degrade various structural carbohydrates such as cellulose, hemicellulose, and pectin. This functionality was in line with the high abundances of the metagenomes associated with carbohydrate metabolism. Consistent with our hypothesis, the abundances of the metagenomes associated with energy metabolism, folding/sorting and degradation, glycan biosynthesis and metabolism, and metabolism of amino acids were higher in adult females relative to adult males. Sex differences were also detected in the bacterial community structure, although no sex differences in the proportions of any bacterial taxa were found likely due to the small sample size. These results suggested that gastrointestinal bacterial communities may aid adult females in increasing energy and nutrition utilization efficiencies compared to adult males. Fecal bacterial communities were found to be more similar between individuals in adult females than in adult males. Our study presented the first examination of the fecal bacterial diversity of a little-studied, endangered foregut fermenter.

In much of the tropics, the proportion of the land covered by regenerating forest surpasses than in primary forest, thus protecting regenerating forest could offer a valuable conservation opportunity, but only if those lands promote faunal recovery. Chapman et al. documented the recovery of populations of six primate species over up to 45 years in Kibale National Park, Uganda and discovered that in preexisting forest, populations of all species grew, except blue monkeys. Populations (except blue monkeys) also increased by colonizing regenerating forests at previously cleared sites. In many cases, populations in these regenerating areas were of comparable size to those in old-growth forest, and there was little evidence that this population increase corresponded with a decline in neighboring old-growth forests. This research demonstrates the potential for management of regenerating forest to be an effective conservation tool and illustrates the importance of conducting and funding long-term monitoring.

Cortisol concentration (CC) is often used as a stress indicator in animals, as high CC is associated with elevated stress levels. During field research, non-invasive methods of measuring CC, such as collection of urine and feces, are superior to using blood samples when monitoring free-ranging animals’ stress levels. However, due to different metabolic pathways, whether CC can be detected in urine and feces to reliably assess stress varies across species. Therefore, it is important to ascertain whether urine and fecal samples are a reliable source for determining CCs and to determine a suitable sampling regime. In this study, we subjected three captive adult golden snub-nosed monkeys (Rhinopithecus roxellana) to a high-stress situation (capture and injection). Urine and feces were collected for four days before and for four days after the manipulations for laboratory analysis. Immunoreactive CC was detected with a commercial enzyme immunoassay (EIA) kit and showed distinct rises. Peak CC values in urine were detected within 5 h, while peak fecal CC ranged between 5 and 24 hours post-interference. These results provide evidence that CC in urine and feces can be used to assess stress levels in the golden snub-nosed monkey. The optimal time frame to collect urinary and fecal samples for CC analysis is within one day of a potential stressful event.