The silvery gibbon is well known for one particular method of communication: singing! These songs are used for a variety of purposes, especially to establish and defend territorial boundaries, and attract mates. Several times a day, females will sing songs to defend their territory. If strangers are spotted, the male will scream alongside the female in an attempt to scare them away. If that doesn’t work, the male will shake branches, becoming more aggressive until he finally chases the intruders away in a large, noisy racket. Unlike other species of gibbon, the breeding pair doesn’t perform “duets”. Rather, the female does the majority of the singing with a variety of sounds, which may also include screeching and “wa” notes. In comparison, the male makes a simple “hoot” when he calls.

Like all primates, silvery gibbons also use visual and tactile gestures and facial expressions to communicate with one another. They hug each other with their arms or legs and sometimes grab the hand or foot of another with one hand for up to a minute or two. To get a point across, they push, pull, slap, kick one another, or even use gentle bites. They nudge and poke at another individual with a finger or fist to get the recipient to move, and touch each other gently or present a body part to initiate grooming. Threat gestures or expressions of frustration include head shaking, grinning, or opening the mouth with the palate and canines fully exposed. On the opposite end of the spectrum, lip-smacking is an expression of friendliness.