Using all the records in which the food types were confirmed (n = 2249), the diet of the study group consisted of slightly more leaves than fruit. Leaves accounted for about 67.7% of the food eaten by the langurs (young leaves 43.9%; mature leaves 23.8%). Fruits and flowers constituted 24.93% of the diet (20.74% fruits and 4.19% flowers), stems and seeds accounted for 6.1% of the diet (4.0 and 2.1%, respectively), and bark and other plant parts constituted 0.24% and 0.97%, respectively (Table 2). Notably, the stems that the langurs consumed were almost all dodder, a parasitic plant. The langurs were very fond of feeding on all the components of the dodder, especially the stems (Yao Wei, personal observation).
There was significant seasonal variation in the types of foods that the langurs consumed most frequently. They ate significantly more mature leaves and seeds and fewer young leaves in the dry season than in the rainy season (mature leaves: χ2 = 6.51, P < 0.05; young leaves: χ2 = 22.45, P < 0.01; seeds: χ2 = 68.67, P < 0.01). The mature leaf consumption was negatively correlated (β = -8.68, Wip = 0.39) with the abundance of fruits, and the young leaf consumption was positively correlated (β = 4.76, Wip = 0.15) with the abundance of young leaves. The flower consumption was positively correlated with the abundance of flowers and fruits (FAI of the flowers: β = 3.28, Wip = 1.00; FAI of the fruits: β = 2.67, Wip = 1.00; Table 4).