Feeding adaptation ofFrançois’ langurs (Trachypithecus francoisi) to thefragmented limestone habitats in Southwest ChinaWei Yaoa,1, Cheng-Ming Huanga,b,1, Jia-Xin Zhaob, Rong Huangb, Wen-Hua Lib,Peng-Lai Fan a,*, Qi-Hai Zhou a,*aKey Laboratory of Ecology of Rare and Endangered Species and Environmental Protection, Ministry of Education, Guangxi Key Laboratory of Rare and Endangered Animal Ecology, Guangxi Normal University, Guilin, Chinab Institute of Zoology, Chinese Academy of Sciences, Beijing, China.c Encheng National Nature Reserve, Chongzuo, China∗Corresponding authorRunning Title: Feeding adaptation of François’ langurs to the fragmented limestone habitatsCorresponding author:Prof. Qi-Hai Zhou, Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection, Ministry of Education, Guangxi Normal University, 1# Yanshan Zhong Road, Guiling, Guangxi 541006, China. E-mail:[email protected] Prof. Pen-Lai Fan, Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection, Ministry of Education, Guangxi Normal University, 1# Yanshan Zhong Road, Guiling, Guangxi 541006, China. E-mail:[email protected] Yao and Cheng-Ming Huang are co-first authorsAbstract: Limestone forests are an unusual habitat for primates, especially fragmented limestone habitats. However, limited research has been conducted on François’ langurs (Trachypithecus francois ) in these habitats, and there is a need to understand their behavioral adaptations to the fragmented limestone habitat. We collected data on the diet of François’ langurs in a fragmented limestone habitat in Encheng National Nature Reserve, southwestern Guangxi, China, and their feeding adaptations to the fragmented forest were examined. The results indicated that a total of 101 species of plants were consumed by the langurs. The langurs ate a higher number of food species throughout the year when compared with other species, maintained a high level of food diversity, and ate more vines. Moreover, they were highly selective in their use of vegetation in their home range, and fewer plants provided a high-quality food source. During the season when food resources were scarce, similar to monkey populations in other geographic populations, the consumption of fruits and young leaves decreased as their availability decreased. This led to the use of other species, such as mature leaves and seeds. Overall, François’ langurs in Encheng National Nature Reserve are generally considered to employ energy minimization strategies. The findings support that François’ langurs adjust their feeding behavior to cope with seasonal and micro-variations in their dietary requirements and to adapt to their particular environment.Key words: François’ langurs, Feeding adaptation, Limestone habitat, Fragmentation