Responses of the occupancy and activity rhythms of typical desert mammals to grazing in Arid Ecosystems

Objective This study aims to quantify the variations in occupancy and activity rhythms of typical desert-dwelling mammals, analyze their behavioral adaptations under anthropogenic grazing disturbance, and uncover the niche mechanisms underlying species coexistence in such contexts. Ultimately, it seeks to provide a scientific foundation for biodiversity conservation in the arid regions of Xinjiang.

Method From May 22 to October 24, 2024, fieldwork was conducted in the Jinghe and Wusu management stations of the Xinjiang GanJiahu Haloxylon Forest National Nature Reserve. A total of 91 infrared cameras were deployed following a 1 km × 1 km grid design. Single-species occupancy models and kernel density estimation were employed to investigate the responses of representative mammals (including the cape hare, goitered gazelle, red deer, red fox, Asian badger, and wild boar) to grazing disturbance across both temporal and spatial dimensions.

Result (1) During the study period, 10 073 effective camera-days of monitoring were accumulated, yielding 2 017 valid images of wild mammals, 2 552 images of livestock activities, and 230 images of human activities. A total of 15 wild mammal species were recorded, including 6 national second-class protected species such as the wolf and Asian lynx. The relative abundances index of species show significant differences. The dominant species were the cape hare, gerbil, and red fox, while the wolf and American mink were rare species.(2) In terms of spatial dimension, species exhibit a differentiation strategy of “specialization-generalization”: red deer and wild boar are specialized types, with their territory occupancy rates being dominated by key factors such as distance from water sources, altitude, and encounter rates with domestic animals, reflecting a high dependence on core resources; while goitered gazelle, cape hare, red foxes, and Asian badger are generalized types, with their territory occupancy rates being driven by weak effects of multiple factors. (3) In terms of temporal dimension, species achieve coexistence through niche differentiation: the diurnal goitered gazelle has a highly overlapping activity time with domestic animals; while red foxes, Asian badger, red deer, wild boar, and cape hare adopt nocturnal or crepuscular activity patterns, effectively avoiding each other in time. The activity peak of goitered gazelle significantly advances with the increase in grazing intensity, while the activity peaks of cape hare and red deer are delayed with the increase in grazing intensity. The rhythms of red foxes, Asian badger, and wild boar remain stable.

Conclusion This study reveals the multi-dimensional responses of desert mammals to grazing disturbance. Spatially, species exhibit a niche differentiation pattern of “specialization-generalization”; temporally, they achieve niche segregation through rhythmic regulation. These findings highlight the behavioral plasticity underlying species coexistence under anthropogenic disturbance, emphasizing the need for species-specific management strategies in the future to enable targeted biodiversity conservation in arid regions.