The O. sibirica (Orientallactaga sibirica), a member of the family Dipodidae, is widely distributed across Central Asia and plays a significant role in grassland ecosystems. While substantial ecological data on this species exists in China, research on intraspecific cranial variation is limited, and no extensive surveys have been conducted within its Chinese distribution range. This study aims to address this gap by capturing O. sibirica specimens from various geographical regions within China, conducting geometric morphometric analyses on their skulls, and examining the influence of current climatic conditions. Additionally, we predict changes in the suitable habitat areas for O. sibirica in China under future climate scenarios. Our results indicate that the major cranial variations in O. sibirica occur in the nasal, parietal, maxilla near the nasal end, zygomatic arch, and preorbital bridge. These features result in skulls from northeastern China clustering furthest from those in the Qinghai-Tibet Plateau. Skull size is primarily influenced by precipitation, whereas skull shape is affected by longitude, altitude, and temperature. Under future global changes, the suitable habitat for O. sibirica is likely to shrink, with the distribution centroid shifting towards higher latitudes in a northeasterly direction. Our analysis reveals that the cranial morphology of O. sibirica exhibits divergent adaptation across different geographical regions, particularly in the Qinghai-Tibet region, which we suggest should be designated as a new subspecies. Concurrently, future global changes are anticipated to alter the extent of suitable habitats in China, necessitating proactive measures to prevent potential rodent outbreaks.

The gut microbiome can be one pathway by which a host rapidly acclimates and adapts to its ecological environment. Exploring how the microbiome has evolved to differ between hosts with different diets provides insights into the profound interactions between hosts and microbes within these systems. In this study, we used DNA metabarcoding techniques and macrogenomic prediction techniques to study the gut microbes of four desert rodent species with different feeding strategies in the same habitat. One species is herbivorous (Spermophilus alashanicus), one is seed-eating (Phodopus roborovskii), another is omnivorous (Dipus sagitta), and the last (Orientallactaga sibirica) has a diet with a relatively high proportion of meat. Diets rich in plants and insects can be challenging to digest due to the abundance of indigestible fiber and stable chitin, respectively. Out of the species studied, the herbivorous Spermophilus alashanicus has the highest density of UCG-005 genes and the highest predicted abundance of genes related to digestive complexity. The composition of Phodopus roborovskii’s microbiome has the highest variation between individuals, yet Phodopus roborovskii has the highest predicted abundance of genes associated with simple sugars—reflecting this species’ potential adaptability to the fiber within plant seeds and its constraints brought about by its smaller body size. The most insectivorous species, Orientallactaga sibirica, exhibits the highest predicted abundance of genes related to chitin degradation. This study has enhanced our understanding of the gut microbiota in the intestines of rodents as they adapt to various dietary strategies.