Fifteen species of plants, including Ficus concinna (Miq.) Miq., Cuscuta chinensis Lam., and Boniodendron minus(Hemsl.) T. C. Chen, were consumed in large quantities throughout the year, accounting for 61.29% of the total records and being the main food of François’ langur. Eight species of plants, includingTaxillus sutchuenensis (Lecomte) Danser, Henslowia frutescens Benth., and Apodytes dimidiate E.Mey. ex Arn., contributed to a relatively high proportion of the annual feeding records (more than 1%) but were only consumed by the langurs for a few months. For the parasitic vines, the proportion of the annual foraging records was relatively high (1.68%), especially in January, accounting for up to 12.93% of the monthly foraging records. In addition, plants, such as Ligustrum lucidum W. T. Aiton and Cinnamomum burmanni (Nees & T.Nees) Blume, were only sporadically recorded throughout the year and were often rare.
There was no significant correlation between the consumption of the food species and the mature leaves, flowers, and abundance of mature leaves and flowers (mature leaves: β = 0.03, Wip = 0.68; flowers: β = -0.102, Wip = 1.00; FAI of mature leaves: β = 2.52, Wip = 1.00; FAI of fruits: β= -0.28, Wip = 1.00), and there was no significant correlation between the consumption of food species and the dietary composition and ecological factors (Table 3). There was also no significant correlation between the dietary diversity and the mature leaves (mature leaves: β = 0.02, Wip = 0.52), and there was no significant correlation between the consumption of the food species and the dietary composition and ecological factors (Table 3).