Francois langur

Scientific name:

Trachypithecus francoisi

Range and habitat:

Francois langurs prefer moist forests with sheltered, rocky areas. They seek out thick jungles, very steep hillsides and deep caves in northern Vietnam and southern China, where their populations are small and fragmented.

Natural diet:

Primarily leaf eaters, Francois langurs also eat fruits, flowers and seeds as available.

Zoo diet:

Mostly vegetables, lettuce and monkey chow.

Size / weight range:

Francois langurs are 22 to 33 inches long and weigh up to 18 pounds.

Life history:

They have about a 6-½ month gestation and mature around 4 years old; they live up to age 30 in zoo environments. Francois langurs live in small family groups of about 3-12 individuals, with one adult male and several females (often related), plus their offspring. The females in the group typically allomother, or care for each others’ babies.

Interesting Facts:


Photo by Toledo Zoo intern Alex Peera

We have a family group that includes a father “Dong Puong” (the largest langur), a mother “Ashes” (look for the white patch on her pelvis) and their offspring. They have had 6 offspring together, 3 of which are currently on exhibit with them: a male, “Deshi” born in 2010, a female, “Kim Ly”  born in 2012, and their new baby boy, “Tam”!  Tam was born in January of 2014, and he was bright orange!  He will slowly fade to brown and become all black within 6 months.


Photo by Toledo Zoo intern Alex Peera

Francois langurs have cool mohawk hair-dos and white sideburns. When baby langurs are born, they are bright orange, but by about 6 months of age they turn black. Biologists think this bright color mimics a native poisonous flower, helping to protect the baby from predators. It also draws attention to the baby from other group members, so they may help protect it.


Photo by Toledo Zoo intern Alex Peera

They have sacculated, or segmented, stomachs (similar to cows), which enables them to better digest the leaves and bark that they eat in the wild. This food is low in nutritional value, so they need to eat a lot of it; their segmented stomach allows for this. 

Their throat sacs expand for some vocalizations, similar to a bull frog.

When you observe them showing their teeth, this is an aggressive behavior; they are not smiling.

Francois langurs have calloused pads on their rumps called ishial pads that allow them sit comfortably on hard or scratchy surfaces.

The Francois langurs at The Toledo Zoo are part of the Species Survival Plan.

Location at the Toledo Zoo:

Primate Forest.
You may also see our langurs on the Primate Cam by visiting our Animal Web Cams page

Conservation Status:

Endangered due to habitat destruction (forest clearance and agriculture) and hunting for meat and medicinal purposes.