3.3 Food choice
The langurs showed significant
selectivity in their diet composition throughout the year. Among the 115
food species (including three non-plant components and 11 plants whose
species names could not be identified) that François’ langur consumed
throughout the year, only 23 plants (20%) accounted for more than 1%
of the total foraging records but contributed to 72.99% of the foraging
records. Among the 23 species of plants, Ficus concinna, Cuscuta
chinensis, Boniodendron minus, Pittosporum pulchrum Gagnep.,
Flueggea virosa (Roxb. ex Willd.) Royle, Pithecellobium
clypearia (Jack) Benth., Pericampylus glaucus (Lam.)
Merr., Vitex kwangsiensis C. Pei, Cudrania cochinchinensis(Lour.) Yakuro Kudo & Masam., and Erythropalum scandens Blume
were among the top 10, contributing to 49.06% of the foraging records.
The François’ langurs did not consume plants within each family evenly.
They used 68 (45.3%) of the 150 plant species marked by the vegetation
surveys in the overall foraging record, which accounted for 89.04% of
the total foraging record (Table 5). Among the top ten tree species in
the vegetation surveys, only Flueggea virosa accounted for more
than 2% of the total foraging records. The correlation analysis showed
that there was no significant correlation between the foraging ratio and
relative density of these 68 plants (Spearman Rank Correlation
Coefficient rs = 0.146, n = 68, P > 0.05), indicating that
there was no strong correlation between the François’ langur’s food
choice and the number of plants in the environment.