Effects of human activity on the habitat utilization of Himalayan marmot (Marmota himalayana) in Zoige wetland

High genetic diversity of the himalayan marmot relative to plague outbreaks in the Qinghai-Tibet Plateau, China

Plague, as an ancient zoonotic disease caused by Yersinia pestis, has brought great disasters. The natural plague focus of Marmota himalayana in the Qinghai-Tibet Plateau is the largest, which has been constantly active and the leading source of human plague in China for decades. Understanding the population genetics of M. himalayana and relating that information to the biogeographic distribution of Yersinia pestis and plague outbreaks are greatly beneficial for the knowledge of plague spillover and arecrucial for pandemic prevention. In the present research, we assessed the population genetics of M. himalayana. We carried out a comparative study of plague outbreaks and the population genetics of M. himalayana on the Qinghai-Tibet Plateau. We found that M. himalayana populations are divided into two main clusters located in the south and north of the Qinghai-Tibet Plateau. Fourteen DFR genomovars of Y. pestis were found and exhibited a significant region-specific distribution. Additionally, the increased genetic diversity of plague hosts is positively associated with human plague outbreaks. This insight gained can improve our understanding of biodiversity for pathogen spillover and provide municipally directed targets for One Health surveillance development, which will be an informative next step toward increased monitoring of M. himalayana dynamics.

Fatty acid metabolization and insulin regulation prevent liver injury from lipid accumulation in Himalayan marmots

Fat storage and weight gain are dominant traits for hibernating mammals. However, excessive fat accumulation may cause liver damage. Here, we explore the lipid accumulation and metabolic processes of the Himalayan marmot (Marmota himalayana), a hibernating rodent species. We find that the unsaturated fatty acid (UFA) content in food was consistent with a large increase in the body mass of Himalayan marmots. Metagenomic analysis shows that Firmicutes Bacterium CAG:110 plays a synergistic role by synthesizing UFAs, which is demonstrated by fecal transplantation experiments, indicating that the gut microbiome promotes fat storage in Himalayan marmots for hibernation. Microscopic examination results indicate that the risk of fatty liver appears at maximum weight; however, liver function is not affected. Upregulations of UFA catabolism and insulin-like growth factor binding protein genes provide an entry point for avoiding liver injury.

Temporal activity patterns of North China leopards and their prey in response to moonlight and habitat factors

The nocturnal activities of predators and prey are influenced by several factors, including physiological adaptations, habitat quality and, we suspect, corresponds to changes in brightness of moonlight according to moon phase. In this study, we used a dataset from 102 camera traps to explore which factors are related to the activity pattern of North China leopards (Panthera pardus japonensis) in Shanxi Tieqiaoshan Provincial Nature Reserve (TPNR), China. We found that nocturnal activities of leopards were irregular during four different lunar phases, and while not strictly lunar philic or lunar phobic, their temporal activity was highest during the brighter moon phases (especially the last quarter) and lower during the new moon phase. On the contrary, roe deer (Capreolus pygargus) exhibited lunar philic activity, while wild boar (Sus scrofa) and tolai hare (Lepus tolai) were evidently lunar phobic, with high and low temporal activity during the full moon, respectively. In terms of temporal overlap, there was positive overlap between leopards and their prey species, including roe deer and tolai hare, while leopard activity did not dip to the same low level of wild boar during the full moon phase. Human activities also more influenced the temporal activity of leopards and wild boar than other species investigated. Generally, our results suggested that besides moonlight risk index (MRI), cloud cover and season have diverse effects on leopard and prey nocturnal activity. Finally, distinct daytime and nighttime habitats were identified, with leopards, wild boar, and tolai hare all using lower elevations at night and higher elevations during the day, while leopards and roe deer were closer to secondary roads during the day than at night.