Social Behaviour

Activity patterns & lifestyle


Arboreal – Individual


Kinship – Family Interaction


Social Structure


Interaction with sympatric species

Arboreal Locomotion

Dusky Langurs love to dwell upon higher canopies of trees in the forest. They prefer staying up there and move around running, climbing and leaping on branches of trees.

Data source: Yap et al., 2019

The behaviour code:
a) Locomotion: (hind-limb dominated)
Quadrupedalism – Climbing, Leaping, Running, Walking
b) Positioning: Lying, Sitting, Standing

Family Matters

An average of 5-20 members in a group, consisting 1 alpha male, 1-2 sub adult male(s), multiple females, subadult females, juveniles, and infants. Both males and females disperse when they are about 3-4 years old.  

When it comes to observing the family behaviour, different kinds of interactions can be observed when they are active. Apart from feeding and moving around, they would take turns to groom each other too. There are several interesting human-like behaviour, such as embracing, chasing and kissing.

Social Languages

Dusky Langurs have their own way to express themselves, here are several behavior that we observed during the field:


The alpha male produce a loud honking sound as an alarm call to let his group be aware of situation, such as presence of predators, human, etc.


Dusky Langur displayed “grief” behavior when losing her infant. 2 days later, it was observed that she was still holding her infant and eventually let go after that.


When Dusky Langurs reach the sexual maturation period, they will be ready for mating. Mounting and copulation will be carry out for around 5s -10s.


The Dusky Langurs will defend their home when there is a threat, by either shaking or breaking the branch to chase the reticulated python away.

Sympatric Species Interactions

Meet the animals that can be found coexisting with the Dusky Langurs in the rainforest. Are they friends? or foe? Let’s find out!

Territorial Defense Behaviour

Wall of Bravery

And the Award of courage goes to …….

Dusky Langurs can be shy at times, but when they faced threats, they will do their very best to keep the invaders away.