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.