Francois' Langur - Behavior

Behavior

François' langur is diurnal and spends most of the day resting and foraging. One study investigated time distribution across activities in a disturbed environment, showing resting 35.41%, foraging 31.67%, traveling 14.44%, huddling 9.61%, playing 8.54%, and grooming 0.33%. Traveling, playing, grooming and huddling are more dependent on the season. Interestingly it has been found that grooming occurs in all seasons but spring. François' langur spends a greater part of its day travelling during the winter (20.12%) and huddling in the spring (14.62%).

François' langur lives in groups of four to twenty-seven langurs, but will usually be found in groups of around twelve. It lives in a matriarchal society where the females lead the group. Within the society, the females perform alloparenting, sharing parenting responsibilities with one another, and are philopatric to the group. Males within the group take no part in the raising of the young, the young males will leave the group before reaching sexual maturity. Young langurs are nursed for up to two years before being weaned, and once weaned the relationship amongst the relatives becomes that of any other member of a given group.

Over 50% of François' langur's diet is made up of leaves. It will also consume fruits (17.2%), seeds (14.2%), flowers, stems, roots, bark and occasionally minerals and insects from rock surfaces and cliffs. This langur consumes its favorite food, young leaves, at the highest rate during the dry season, April through September; between October and March when young leaves are less common, the langur supplements its diet with seeds, petioles, and stems.

François' langur is selective in its diet, in Nonggang Nature Reserve, China, it primarily eats the young leaves of ten different species of plant, only two of which are common within the reserve. Its diet includes Pithecellobium clypearia, Ficus nervosa, Garcinia pauncinervis, Sinosideroxylon pedunculatum, F. microcarpa, Miliusa chunni, Securidaca inappendiculata, Bauhinia sp., and Canthium dicoccum. Though these are the preferred plant species, it will still consume other plant species opportunistically. Another study on François' langur in a fragmented habitat found that it preferred on just four plant species: litse, Litsea glutinosa; seatung, Pittosporum glabratum; Cipadessa cinerascens; and Chinese desmos, Desmos chinensis. The study showed that the langur spent 61.6% of its feeding time on these four plant species, and 38.4% of its time on 36 other known species.