Species Fact Profile: Francois' Langur (Trachypithecus francoisi)

                                                                   Francois' Langur

                                            Trachypithecus francoisi (de Pousargues, 1898)

Range: Southern China (Guangxi Province), northern Vietnam, and west-central Laos

Habitat:  Lowland Tropical and Subtropical Rainforest, Evergreen Broadleaf Forest (especially associated with limestone karst outcroppings), up to 600 meters elevation

Diet:  Leaves, bark, shoots, seeds, flowers, and nectar

Social Grouping: Social groups usually consist of one male with multiple females, 3-30 individuals total (average is 12)

Reproduction: Breeding takes place throughout the year, peaking in autumn and winter.  Single infant born once a year after gestation period of 6-7 months.  Weaned at about 2 years old.  Sexually mature at 4-5 years old

Lifespan: 25 Years

      Conservation Status:  IUCN Endangered, CITES Appendix II.  USFWS Endangered

• Body length 40-76 centimeters, tail length 74-96 centimeters, weight 4-14 kilograms.  Males are slightly larger than females (also have longer tails).  Small heads (crowned with a long, pointed crest) lacking cheek pouches.  Tail is long and straight.  Forelegs shorter than high legs.  Thumbs are well-developed and opposable
  
• Fur is uniform brown, black, or dark gray, with a white stripe running from the corner of the mouth to the ear, resembling sideburns.  There is also a smaller amount of white in the crest above the eyes, resembling eyebrows.  Infants are golden-yellow with a black tail, transitioning to adult coloration at about 6-12 months old 
  
• Home range size of about 150 hectares, daily range about 1,000 meters.  Males defend the territory with hoarse vocalizations.  Juvenile males leave the natal troop at 3-4 years old and either form a bachelor group or try to join another family troop.  Females remain in the troop
  
• Highly arboreal, typically moving through the trees on all four legs.  Sometimes jump from tree to tree by pushing off with their hind legs.  Active by day.  Often encountered resting on cliff ledges (long periods of rest needed to facilitate digestion).  Sleeps in limestone caves (may have more than half a dozen regularly used sleeping sites in range, rotated to avoid predators)
  
•  Other females in a troop will assist mother with raising her young, may adopt infant if mother is killed.  It is possible that it is the bright orange coloration of the juvenile which triggers paternal behavior in other langurs.  Males do not assist in rearing the young
  
• Leaves are the more important component of the diet in the dry season, other foods in the wet season.  Large forestomach (part of a multi-chambered stomach) hosts bacteria to digest cellulose 
  
• Most significant predator of adults is cloudedleopard.  Juveniles are vulnerable to large raptors, such as crested serpent eagle and mountain hawk-eagle.  Predation not considered to be a major source of mortality
  
• Northernmost range of any langur species
•  Species is named after Auguste Francois, the French Consul at Lungchow, Kwangsi, China who identified specimens in the wild
  
• Threats include loss of habitat both for logging and agricultural expansion (fires used to clear forest for fields also destroy feeding sites – limestone is also vulnerable to fire, leading to the destruction of resting sites), hunting for food and use in Traditional Chinese Medicine (used to make “black ape wine”), capture for the pet trade