Siamangs duetting, Malaysia
This has to be one of the loudest wildlife sounds you’ll hear in south-east Asia. I recorded the calls of this small family group of Siamangs near The Gap in Malaysia. They were high up in the canopy of primary hill rainforest near to the edge of their group’s territory and calling in response to another group across the valley.
Siamangs are significantly larger than other gibbons, and their calls are particularly loud (other gibbons are loud too, but I think the Siamang can turn the volume up a notch due to their large throat pouches). Pairs duet in complex calling bouts to advertise their presence. Four distinct classes of vocalizations have been documented by scientists: booms, barks, ululating screams and bitonal screams. Females typically produce long barks and males generally produce bitonal screams, but both sexes have been known to produce all four classes of vocalization.