Gastrointestinal microbiota play an important role in animal host immunity, nutrient metabolism, and energy acquisition, and have therefore drawn increasing attentions. This study compared the diversity of the gut microbiota of both wild and captive bharals, which is an ungulate herbivore of caprid from the Qinghai-Tibet plateau. The sequencing of the V4-V5 region of the 16S rRNA gene via high-throughput sequencing technology showed that the dominant bacterial phyla are Firmicutes and Bacteroides both in wild and captive bharals. However, their abundance differed significantly between groups. Firmicutes were significantly higher in wild bharals, while Bacteroides were significantly higher in captive bharals. Different diets are likely a key influencing factor in the diversity and abundance of gut microbiota in bharals. Changes in diets affect the diversity of gut microbiota and the relative abundance of pathogenic bacteria, increasing the risk of diseases outbreak in captive bharals. The results of this study suggest that the structure and function of the gut microbiota should be regulated via dietary intervention, accurate provision of an individualized diet, and optimization of the functional network of gut microbiota and its interaction with the host. This will improve the ex situ protection of wild animals.

Gut microbiota forms a unique microecosystem and performs various irreplaceable metabolic functions for ruminants. The gut microbiota is important for host health and provides new insight into endangered species conservation. Forest musk deer (FMD) and alpine musk deer (AMD) are typical small ruminants, globally endangered due to excessive hunting and habitat loss. Although nearly 60 years of captive musk deer breeding has reduced the hunting pressure in the wild, fatal gastrointestinal diseases restrict the growth of captive populations. In this study, 16S rRNA high-throughput sequencing revealed the differences in gut microbiota between FMD and AMD based on 166 fecal samples. The alpha diversity was higher in FMD than in AMD, probably helping FMD adapt to different and wider habitats. The ß-diversity was higher between adult FMD and AMD than juveniles and in winter than late spring. The phylum Firmicutes and the genera Christensenellaceae R7 group, Ruminococcus, Prevotellaceae UCG-004, and Monoglobus were significantly higher in abundance in FMD than in AMD. However, the phylum Bacteroidetes and genera Bacteroides, UCG-005, Rikenellaceae RC9 gut group, and Alistipes were significantly higher in AMD than FMD. The expression of metabolic functions was higher in AMD than in FMD, a beneficial pattern for AMD to maintain higher energy and substance metabolism. Captive AMD may be at higher risk of intestinal diseases than FMD, with higher relative abundances of most opportunistic pathogens and the expression of disease-related functions. These results provide valuable data for breeding healthy captive musk deer and assessing their adaptability in the wild. Key points: • Alpha diversity of gut microbiota was higher in FMD than that in AMD • Expression of metabolic and disease-related functions was higher in AMD than in FMD

Habitat connectivity is indispensable for the survival of species that occupy a small habitat area and have isolated habitat patches from each other. At present, the development of human economy squeezes the living space of wildlife and interferes and hinders the dispersal of species. The Przewalski’s gazelle (Procapra przewalskii) is one of the most endangered ungulates, which has experienced a significant reduction in population and severe habitat shrinkage. Although the population of this species has recovered to a certain extent, human infrastructure severely hinders the gene flow between several patches of this species. Therefore, we used the maximum entropy (MaxEnt) model to simulate the habitat suitability of the Przewalski’s gazelle. In addition, we combined habitat suitability and ecological characteristics of the species to obtain eight habitat patches. Finally, we used the least-cost path (LCP) and circuit theory based on the resistance model to simulate the landscape network of this species. The results showed that habitat patches and connectivity in the east of the Qinghai Lake were crucial to the communication between populations of the Przewalski gazelle, and our study provided important reference for the distribution of important habitats and the construction of corridor between patches. Our study aimed to provide habitat networks and maintain landscape connectivity for achieving the fundamental goal of protecting and revitalizing populations of the Przewalski’s gazelle.

The composition of gut microbiota is closely related to health and nutrition of livestock. Research on the interaction between gut microbiota in livestock and grazing management strategies is unfortunately sparse. By studying the compositions of gut microbiota in sheep and goats in a single, mixed grazing population under the control of herdsman, as well as those of free-range camels in the same area of Qaidam Basin, we found that the composition of gut microbiota between sheep and goats showed no significant difference. However, there were significant differences between mixed group and camels at α- and β-diversities. We speculate that grazing management can shape gut microbial diversity indirectly. Mixed grazing under the control of herdsman lead to similarities in the diversity of gut microbiota among different species and limit their diversities of gut microbiota, which is not conducive to healthy growth of the host. On the contrary, free-range grazing is better for the diversity of gut microbiota. In order to sustainably manage populations of livestock, gut microbiota analysis may prove to be an important indicator for evaluating the merits of different grazing management strategies. Our results lay a foundation to improve the health of livestock and grazing management.