Long-term camera trap monitoring of mammalian diversity and activity rhythms of threatened species in Xianxialing Nature Reserve, Zhejiang Province, China

Research on mammalian diversity and activity rhythms is critical for understanding biological adaptation, evolutionary processes and the development of effective ecological conservation strategies. Xianxialing Nature Reserve in Zhejiang Province is an area with rich mammalian biodiversity, yet no study has been conducted on mammalian activity rhythms in the Reserve. This study aims to systematically monitor and document mammalian diversity and characterise the activity rhythms of threatened species in the Xianxialing Nature Reserve using infrared camera traps. Between January 2021 and November 2023, this survey used 97 continuously monitored infrared cameras, generating totals of 71,879 effective camera-days of data. In total, 24,919 effective records were obtained, representing 12 independently detected non-rodent mammal species belonging to seven families, 10 genera and four orders. Based on the Relative Abundance Index (RAI), the five most abundant species were Reeves' Muntjac ( Muntiacus reevesi ), Masked Palm Civet ( Paguma larvata ), Hog Badger ( Arctonyx collaris ), Chinese Ferret-badger ( Melogale moschata ) and Rhesus Macaque ( Macaca mulatta ). Compared with diurnal species, nocturnal species, such as the Masked Palm Civet, showed a preference for lower-altitude habitats during winter. These spatial distribution patterns can be attributed to a combination of thermoregulatory strategies and other ecological drivers. Overall, the findings provide an objective assessment of the current status of mammalian diversity in Xianxialing Nature Reserve. Studying mammal activity rhythms offers baseline data and practical insights for the dynamic conservation of nationally protected species in China's subtropical nature reserves.