The Spatial Niche and Influencing Factors of Desert Rodents.

Simple Summary: Rodents in the Alxa desert area (Inner Mongolia, China) face more human disturbance (including grazing, reclamation, excavation of wild medicinal materials, etc.) than in other areas. We used the capture-mark-recapture method to continuously monitor the four main rodent spatial niches from 2017 to 2021. At the same time, we monitored the vegetation, soil, temperature, and humidity in the survey area. The results showed that the spatial niche breadth of rodents was mainly affected by population density (rodents) and shrubs (height and density) in the habitat. The coexistence strategy of the northern three-toed jerboa (Dipus sagitta) with midday gerbil (Meriones meridianus) and desert hamster (Phodopus roborovskii) is based on the difference in body size and foraging strategy. The five-toed jerboa (Orientallactaga sibirica) promotes coexistence through spatial niche separation. Rodents can make a trade-off between foraging efficiency and the cost of travel to achieve coexistence. Resource partitioning may allow species coexistence. Sand dunes in the typical steppe of Alxa Desert Inner Mongolia, China, consisting of desert, shrub, and grass habitats, provide an appropriate system for studies of spatial niche partitioning among small mammals. In this study, the spatial niche characteristics of four rodents, Orientallactaga sibirica, Meriones meridianus, Dipus sagitta, and Phodopus roborovskii, and their responses to environmental changes in the Alxa Desert were studied from 2017 to 2021. Using the capture-mark-recapture method, we tested if desert rodents with different biological characteristics and life history strategies under heterogeneous environmental conditions allocate resources in spatial niches to achieve sympatric coexistence. We investigated the influence of environmental factors on the spatial niche breadth of rodents using random forest and redundancy analyses. We observed that the spatial niche overlap between O. sibirica and other rodents is extremely low (overlap index ≤ 0.14). P. roborovskii had the smallest spatial niche breadth. Spatial niche overlap was observed in two distinct species pairs, M. meridianus and D. sagitta, and P. roborovskii and D. sagitta. The Pielou evenness index of rodent communities is closely related to the spatial distribution of rodents, and the concealment of habitats is a key factor affecting the spatial occupation of rodents. [ABSTRACT FROM AUTHOR]