Animal Info - Francois' Leaf Monkey

(Other Names: Francois' Black, Tonkin, or White-sideburned Leaf Monkey; Francois' Langur; Langur de Francois or de François; Semnopithèque de François)

Trachypithecus francoisi (Presbytis f., Semnopithecus f.)

Status: Vulnerable

1. Profile (Picture)
2. Tidbits
3. Status and Trends (IUCN Status, Countries Where Currently Found, Population Estimates, History of Distribution, Threats and Reasons for Decline)
4. Data on Biology and Ecology (Weight, Habitat, Maximum Age, Diet, Behavior, Social Organization, Density and Range)
5. References

Profile

Pictures: Francois' Leaf Monkey #1 (28 Kb JPEG) (Univ. Wash.); Francois' Leaf Monkey #2 (50 Kb JPEG) (Honolulu Zoo)

Francois' leaf monkey weighs 6 - 9 kg (13 - 20 lb). It is found in tropical monsoon forest and well-sheltered rocky areas in limestone hills and caves. Its diet is comprised mostly of leaves and some flowers and fruits. One male leads a family group of 3 - 12 individuals, including 4 - 6 females and several young. Family groups sleep outside in mild weather and in caves during cold winters. Members of the genus Trachypithecus spend most of their time in the trees, although animals will travel on the ground between food trees, despite the increased risk of predation (Davies & Oates 1994).

Francois' leaf monkey has been reported from southeastern China (Guangxi and Guizhou Provinces), central Laos east of the Mekong River, and northern Vietnam. It has declined because of habitat loss, due to expansion of agriculture, fuelwood harvesting, warfare and logging; and because of hunting for food and Oriental medicine.

Tidbits

*** The unusual nature of the stomach of leaf monkeys and related species probably has a profound influence on their ecology. The stomach is large and multi-chambered, and the forestomach supports bacteria with cellulose-digesting abilities. These monkeys are enabled by their stomach to digest plant fibers, and many include large quantities of foliage in their diet. (Davies & Oates 1994)

Status and Trends

IUCN Status:

1988 - 1994: Endangered
1996 - 2004: Vulnerable (Criteria: A1cd+2cd, C2a) (IUCN 2004)

Countries Where Francois' Leaf Monkey Is Currently Found:

2004: Occurs in China, Laos and Vietnam (IUCN 2004).

Population Estimates:

[Note: Figures given are for wild populations only.]

WORLD
- 1987: Less than 25,000 (WCMC/WWF 1997aa)
China
- 1984: 600 (Oryx 1984b)

History of Distribution:

Francois' leaf monkey has been reported from southeastern China (Guangxi and Guizhou Provinces), central Laos east of the Mekong River, and northern Vietnam.

Threats and Reasons for Decline:

Francois' leaf monkey has declined because of habitat loss, due to expansion of agriculture, fuelwood harvesting, warfare and logging; and because of hunting for food and Oriental medicine.

Data on Biology and Ecology

Weight:

Francois' leaf monkey weighs 6 - 9 kg (13 - 20 lb).

Habitat:

Francois' leaf monkey is found in tropical monsoon forest and well-sheltered rocky areas in limestone hills and caves.

Francois' leaf monkey is found in both the Indo-Burma Biodiversity Hotspot (Cons. Intl. 2005) and the Annamite Range Moist Forests and the Northern Indochina Subtropical Moist Forests Global 200 Ecoregions. (Olson & Dinerstein 1998, Olson & Dinerstein 1999)

Maximum Age:

Up to 28 years (captivity).

Diet:

Mostly leaves and some flowers and fruits.

Behavior:

Family groups sleep outside in mild weather and in caves during cold winters. Members of the genus Trachypithecus spend most of their time in the trees, although animals will travel on the ground between food trees, despite the increased risk of predation (Davies & Oates 1994).

Social Organization:

One male leads a family group of 3 - 12 individuals, including 4 - 6 females and several young.

Density and Range:

Density: 3 individuals/sq km (8 individuals/sq mi) (Trachypithecus francoisi francoisi) (Le Xuan Canh 1997)

References

Cons. Intl. 2005, Davies & Oates 1994, Honolulu Zoo, IUCN 1994, IUCN 1996, IUCN 2000, IUCN 2003a, IUCN 2004, Le Xuan Canh 1997, Macdonald 1984, Olson & Dinerstein 1998, Olson & Dinerstein 1999, Oryx 1984b, Univ. Wash., WCMC/WWF 1997aa

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Last modified: March 16, 2005;