3.2 Overall diet and seasonal variations
During the study, the langurs consumed 101 plant species from 43 families. Among the 101 identified tree species, 58.26% were trees (n = 67), and 2.61% were herbaceous (n = 3), accounting for 66.13% and 1.19% of the foraging records, respectively. Additionally, the langurs consumed 29 species of lianas, accounting for 22.66% of the diet and six of the top 20 species consumed. Furthermore, the langurs consumed two species of parasitic plants, accounting for 7.39% of the diet and two of the top 20 species consumed. The langurs also ate nest material, a food that has not been recorded in other studies, accounting for about 0.29% of the total foraging record (n = 2249). In addition, at least one insect was eaten (n = 2249, 0.04%; Table 2).
Each month, the langur group consumed between 24 species (April) and 49 species (January), with a monthly average of 38 (standard deviation [SD] 6.64; Table 2). The monthly dietary diversity varied from 2.2 (August) to 3.4 (January), with an average of 3.08 (SD 0.35; Table 2). Additionally, the monthly dietary diversity and the number of food species that were consumed varied seasonally during the study period (species number: χ2 = 6.33, P < 0.05; dietary diversity: χ2 = 3.52, P < 0.05). The langurs consumed more species and obtained a higher dietary diversity in the dry season than in the rainy season.