Primate Species Profile Essay, Research Paper

Primate Species Profile

Red-shanked Douc Langurs

What are their names?

Scientific name: Pygathrix nemaeus

English name: Red-shanked douc langurs

How are they classified?

Order: Primata

Family: Cercopithecidae

Did you know…..

- That Douc langurs are leaf-eating monkeys with long intestines and very large

stomachs to get nutrients out of leaves. Leaves are difficult to digest, so therefore, the

langurs spend most of their time sleeping in order to properly digest them. They leaves

they eat ferment inside them as part of their natural digestion, which releases bubbles of

gas and causes them to burp!

- Douc langurs have a specific “playface” in which the eyes are closed, exposing

very pale blue eyelids.

- The tails of Douc langurs are actually longer than their body.

- Douc langur babies are very susceptible to the pet trade because they are so cute.

Unfortunately most of these babies die due to lack of proper nutrients because their

owners feed them only fruits – and they need many other nutrients for a balanced, healthy

diet.

Where do they live?

Douc langurs are found most frequently in primary evergreen forests of Vietnam and

Laos (also in Cambodia), at around 300-2000 meters elevation.

Recent fieldwork has demonstrated that although douc lagurs were once thought to have

a restricted habitat, they are actually found in a variety of habitats. While douc langur

monkeys are restricted to wooded areas, they occur in a variety of forest types.

Populations of doucs have been located from both monsoon forests as well as rainforests

and include: semi-evergreen, lowland lower montane and upper montane forest types.

What are their general characteristics?

Description: Douc langurs appear as if dressed in costume. They have grey-black

underparts, and the upper part of the leg is also black, and finally continuing down the

knee and below are orange-red. Cheeks and throat are white, and the hands, feet, brow,

and shoulders are a contrasting black. The tail, forearms, and genital region are also

white.

There is no sexual dimorphism in the size of douc langurs, and the size ranges are the

following: the body length ranges from 23.1-23.5 inches, the tail length ranges from

23.5-26.8 inches, and their weights range from 18.1-24.0 lbs.

Diet: Douc langurs are vegetarians, getting adequate protien and fluid by eating leaves,

buds, fruit, and flowers. They eat 50 species of plant but no animals. At the zoo, the

animals eat primate chow and various types of greens that they get in a rotating diet.

That way the animals get to choose which type of green they want.

The keepers at the zoo also like to include enrichment activities in the feeding process.

This includes using puzzle feeders and having the animals fish their food out of the water

(since they like to soak thier chow!).

Mating and caring for young: Douc langurs live in multimale-multifemale groups with 2

females to one male. Allo-mothering is also common in captivity, which is the sharing of

the infant with the other members of the group. Before mating, both genders give a

sexual signal with the jaw forward, eyebrows raised and then lowered, and a head shake.

Single mount and muliple mount matings have been reported. The gestation period is

approximately 165-190 days, and a black-faced infant is born. Sexual maturity is reached

at 48 months for a male and 60 months for a female, whose estrus cycle comes every 28-

30 days.

Behavior: Red-Shanked douc langurs live in groups of usually 4-25 animals, but up to

40. They are dinural and arboreal animals, using the high canopy to locomote

quadrupedally. They are visually dramatic as they travel – holding their arms

outstretched above their heads to make spectacular 15-18 foot leaps from tree to tree.

These animals rest more and have lower levels of aggression due to digestion, since they

eat leaves and need to sleep often to digest. These animals are partially sympatric to the

black-shanked douc langurs in Vietnam’s central highlands.

They vocalize by a low-pitched growl that is given as a threat, and also have a call that is

short and harsh which is used as a distress signal.

Longevity: They have been known to live up to 30 years in captivity.

What is their conservation status in the wild?

Douc langurs are one of the most endangered primates in the world. They are classified

as endangered by the IUCN and the USDI and are on appendix 1 of the CITES. Bombing

and defoliants during the Vietnam War destroyed most of the douc’s habitat, from which

they never fullly recovered. Also due to their appealing appearace, many douc langur

babies are used in the pet trade and never survive.