Scientific Name: Trachypithecus francoisi
Though its name may sound French, don’t be fooled: this primate is actually from Southeast Asia. The François langur was named for a Monsieur François, who was a French Consul in China when he first observed these animals.
The slender black monkey with the hat-like crest known widely as François’s langur is actually anywhere from five to seven subspecies that have been grouped together for their genetic, behavioral, and geographic similarity.
STATUS: François’s langurs are currently listed as Endangered on the IUCN Red List. Unfortunately, these monkeys continue to be hunted for use in traditional Asian medicines. Additionally, deforestation has contributed to the decline and increasing fragmentation of their populations.
HABITAT: In the wild, François’s langurs can be found from central Laos and Vietnam, to southeastern China. They split their time between the trees and the ground, making their homes in semi-tropical forests and rock formations. They often retreat to caves in limestone karst hills for refuge from the elements and predators (including people).
DIET: One of the François’s langur’s alternate names provides a clue as to what this monkey primarily eats. Called “leaf monkeys,” these langurs’ diet consists primarily of—you guessed it—leaves! Like other folivorous (leaf-eating) animals, these langurs have a specialized stomach with multiple chambers to help them break down cellulose, the indigestible fiber found in plants. Because of this energy-consuming process, they spend reportedly nearly 70% of their time resting and digesting.
In addition to leaves, though, langurs also consume fruits, seeds, and occasionally insects.
PHYSICAL CHARACTERISTICS: Adult François’s langurs have a distinctive crest of hair on their heads and white mutton chop sideburns that contrast sharply with their predominantly black bodies and faces. Males are a little larger than females, but both sexes are roughly two feet tall, and have long tails and delicate hands. Infants have bright ginger fur, which may aid mothers in keeping track of their babies. Their color changes to the less conspicuous black after roughly one year.
François’s langurs are diurnal (active during the day). A noisy bunch, they careen through the treetops looking for tasty leaves and fruits.
François’ langurs tend to live in “harems” of a single male and many females, plus all of their offspring. When infants are born, they are cared for by both their own mothers and unrelated babysitters—called “allomothers” or sometimes “aunts.” This behavior may provide parenting practice for young langurs who have not yet had offspring of their own, as well as giving moms a much-needed break.