Camera trap survey of mammal diversity and activity rhythms of threatened species in a subtropical forest of Huangshan Mountain, China

Understanding the activity rhythms of threatened mammals is crucial for designing effective conservation strategies. However, the systematic studies on mammals in Huangshan Mountain, one of China’s most biodiverse regions, are limited. Therefore, the current study aimed to document the diversity of medium- and large-sized mammals alongside the daily and seasonal activity rhythms of threatened species in the Jiulongfeng Nature Reserve of Huangshan Mountain. A survey employing 32 infrared cameras over 7964 camera-days from March 2022 to March 2023 yielded 7625 independent detections of 15 species belonging to five orders, 13 genera and 10 families. The top five species with the highest relative abundance index (RAI) values were Reeves’s Muntjac ( Muntiacus reevesi ), Wild Boar ( Sus scrofa ), Tibetan Macaque ( Macaca thibetana huangshanensis ), Masked Palm Civet ( Paguma larvata ), and Malayan Porcupine ( Hystrix brachyura ). We describe the diel activity rhythms and seasonal altitudinal migration patterns of seven focal threatened species. The daily activity patterns of Reeves’s Muntjacs, Black Muntjacs ( Muntiacus crinifrons ) and Tibetan Macaques were bimodal and predominantly diurnal, whereas Masked Palm Civets, Malayan Porcupines, Hog Badgers ( Arctonyx collaris ), and Serows ( Capricornis sumatraensis ) were nocturnal. Activity peaks also shifted seasonally. We further observed seasonal altitudinal migration patterns: diurnal mammals, such as Reeves's Muntjacs, Black Muntjacs and Tibetan Macaques, frequented mid-altitude in summer, while nocturnal species, such as Hog Badgers, Malayan Porcupines and Masked Palm Civets were more common at mid-altitude in winter. This pattern could be attributed to thermoregulation and other ecological factors. This work contributes valuable baseline data on mammalian biodiversity and behavioural ecology in an understudied region, with implications for the conservation management of protected areas in subtropical China.