Orangutan cultures

Possible Cultural Variants

The list is based on the experience of many field workers in different sites and is meant to give ideas. ALWAYS describe the locally observed variant in detail, and try to get video footage whenever possible.




Pillow, ‘bantal’ a pile of twigs or big leaves at one side of the nest on which the focal puts its head when lying down
Artistic pillows a row of twigs, all of similar size, all radially-oriented along the nest perimeter with the forked or leafy end out, lining the nest
Blanket (loose nest cover), ‘selimut’ a loose cover made from branches or leaves covering (only) the body (not the head)
Lining, ‘alas’ a layer made on the nest from leaves or twigs on top of which the focal lies down
Roof (fixed roof over nest), ‘atap’ a construction made from branches or twigs hanging together on top of the nest (mostly protection against rain)
Sun cover a cover built over a nest when exposed to bright sunshine (rather than rain)
Bunk nests a second nest, built a short distance above the nest used for resting as a rain-shelter
Hide/shelter under nest build a nest but rather than resting in it the individual moves under it to seek shelter during rain
Leaf bundle while sleeping ("leaf doll") gathering a bundle of leaves and taking them into their night nests, presumably to hold while sleeping
Twig biting systematically passing ends of twigs used for lining of nest past the mouth (sometimes including actual bite) during last part of nest building
Carry leaves to nest pick and carry leaves to nest site from other tree (e.g. Tarantang, Campnosperma sp.) before start of nest building. These leaves can be used for lining, pillow, roof etc.
Nesting in multiple trees building a nest by tying several smaller trees together
Raspberry - sound spluttering sounds (made by expelling air through relaxed, pouted lips) associated with nest building. Nest raspberries may be made before or after completion of the nest.
Nest smack, ‘nyeletok’ smacking/clicking sounds while making a nest
Bridge nest building a nest connecting 2 trees on opposite banks of a stream. Rather than resting in this nest the orangutan uses it to cross the river and continues moving on the other side
Play nests building a day nest (mostly by immatures), in which individuals do not rest, but only play. Building is done in the presence of play partner.
Branch-cushion Covering big branch with a few leaves or leafed branches, then rest on this, no intertwining of bent branches as in a nest.



Severed vine swing Biting through a vine (so that it hangs loose on one end), to swing Tarzan-like to across a gap.
Liana tree release bite Biting through a vine to release a tree to sway to reach adjacent tree.
Treetop break swing Break top of tree to use as a swing to reach another (usually smaller) tree.
Branch-hook using a detached branch to pull branch of adjacent tree within reach
Wading through water walking, often bipedally, through standing water



Hiding behind branch using a detached branch as a screen to hide from predators or humans
Branch dragging display (on ground) dragging a broken branch (as the individual moves across the forest floor), in a display similar to the agonistic display of bonobos
Missiles throwing or aimed dropping of branches, large fruits or other objects toward terrestrial predators (or humans), apparently to drive them away
Snag crashing aimed pushing of dead standing trees as a display to conspecifics, humans or predators
Snag riding push over a dead tree (snag), then hold on to the snag and ride down as it falls, grabbing onto nearby vegetation to stop their own fall before the snag crashes to the ground
Sneaky nest approach building a series of ever-closing nests, not using the nests for resting, but instead moving in closer and building another to cautiously approach another, higher-ranking conspecific
Safe nest Using a nest as social refuge by female when harassed by male
Coercive hand-holding male holding hand/wrist or foot/ankle of female for prolonged periods during consort (often in presence of other male)
Copulation on nest Cooperative copulation on nest of the male
Genito-genital rub (females) pairs of female orangutans rubbing their genitals together(similar to the behaviour commonly reported for female bonobos)



Tree-hole tool-use using (twig) tools to poke into tree holes to obtain social insects or their products
Seed extraction tool-use using (twig)tool to extract seeds from the protected fruits of Neesia sp., which are embedded in irritating hairs, hidden within the very tough outer casing of the fruit and exposed only through slowly opening fissures in the fruit`s valves as the fruit dehisces
Stick as chisel using a stick to break open a termite nest in a log on the ground
Branch as swatter using detached leafy branches to ward off a swarm of insects (bees/wasps) attacking subject (who is raiding their nest)
Leaf gloves using leaf gloves to handle spiny fruits (e.g. durian) or as seat cushions in trees with spiny branches (e.g. Erythrina
Leaf body scrub using a leaf or leaves to wipe off/clean water or dirt from body surface
Leaf napkin using handful of leaves to wipe latex off chin after eating some fruits
Leaf "umbrellas" using large leaves or leafy branches to cover the head most often during rain or, play. Note if in other context.
Scratch (with) stick using a tool for auto-grooming (for example: using a detached stick to scratch body parts)
Autoerotic tool using tool (generally a detached stick) to stimulate genitals, or masturbate (female and male)



Drink water with hand (finger -drip) drink water with hand either from ground or from tree-hole (hand-dip-drip method)
Drink water with cupped-hand drink water from cupped hand with which individual scoops water from ground or tree-hole
Branch scoop use a leafy branch to extract water from deep tree-holes.
Drink sponging use crumpled leaves to absorb water from a tree hole, then drink the water from the leaves
Drink from leaf scoop drink water using leaf as vessel (drinking straight from vessel): ‘leaf-dipping
Drink from leaves drink water dripping from a bundle of wet leaves held above the mouth ‘leaf drip method’
Drink from pitcher plant drink from pitcher plant like a cup
Pitcher plant-bite biting open a pitcher plant from the bottom to drink the fluid
Wash food wash food: dipping food underwater before eating it
Leaf stripping with hand obtaining foliage by drawing a segment of vine, liana or branch rapidly through a partially closed hand, to gather a handful of leaves before consumption
Leaf stripping with mouth obtaining foliage by drawing a segment of vine, liana or branch rapidly with the mouth, to gather a bunch of leaves before consumption
Dead twig sucking breaking hollow (dead) twigs to suck the ants from inside
Bouquet feeding Using lips to pick ants from fistful of dry, or fresh, or rotting leaves (Certain genera of ants make their nests in leaves (e.g. Oecophyllus sp).
Nest destruction rummaging through old orangutan nests for insects, taking the nest apart while doing so
Slow Loris eating capturing and eating slow Loris (Nycticebus coucang) hiding in dense vegetation



Symmetric scratch exaggerated, long, slow, symmetrical scratching movements with both arms at same time, in something that resembles calisthenics or t`ai chi.
Fur sopping Lathering of fruit pulp or seeds on fur of arms (various plant spp)
Autoplay with water splashing water with hands/feet without obvious feeding/drinking purpose, scooping water over body or even dipping/immersing (part of) body under water (‘bathing’)



Kiss-squeak (KSQ) a vocalization/facial expression commonly given by orangutans in contexts suggesting mild alarm or annoyance towards conspecifics or observers. Several variations may be distinguished (see below.
KSQ (unaided) KSQ only with mouth
KSQ with leaves wiping a fistful of crumpled leaves over the face, then dropping the leaves (in similar context to the KSQ, often accompanies the KSQs)
KSQ on (bunch of stripped) leaves (on arm) using leaves that are held near or in front of the mouth during the KSQ (apparently to amplify the sound; Peters 2001), then allowing the leaves to fall.
KSQ with hand(s) KSQ with a hand in front of the mouth (several variations follow)
KSQ with finger/thumb in mouth KSQ with a finger or thumb in mouth
KSQ with (whole) hand (trumpet style) KSQ holding the hand(s) like a trumpet in front of the mouth
KSQ with fist KSQ with fist in front of mouth
KSQ on inside (palm) of hand KSQ on inside (palm) of hand
KSQ on back of hand KSQ on back of hand
KSQ on inside wrist; KSQ on inside wrist
KSQ with mouth-wrap KSQ with hand wrapped around mouth
KSQ on arm KSQ on arm
KSQ on branch KSQ with (on tip of broken) branch
KSQ on tree trunk KSQ on tree trunk
Throat scrape Repetitive deep throat sound made by female towards offspring.