Gibbons use duets in coordinated pair displays.
A gibbon duet is a precisely timed vocal performance by a mated pair, often involving alternating or overlapping phrases. The calls help advertise a territory and reinforce the bond between the two adults. Depending on the species, males and females may contribute different parts of the performance.
Gibbon songs can be remarkably loud and carry through dense Southeast Asian forests. They are not identical across all gibbon species: song structure, timing and the relative roles of males and females vary. This is why “duet” describes the coordinated format rather than one universal gibbon sound.
Gibbons are lesser apes, not monkeys. Their long arms and specialized shoulder joints support brachiation, or swinging through trees, while their vocal displays provide a long-distance communication system in habitats where visibility is limited.