Traffic noise may be changing the songs of Malaysia’s gibbons

In a healthy tropical forest, the morning chorus is filled with birds, insects, and the distinctive songs of gibbons. However, researchers from Universiti Sains Malaysia discovered that gibbon groups living near noisy roads call less frequently than those in quieter areas. This finding, based on recordings taken in 2023 and 2024, shows that gibbons near a highway called in only 36% of recordings, compared to 71.4% near a quiet seaside location and 84.6% near a hiking trail.

Gibbons use their powerful calls for communication, territorial interactions, and social bonding over long distances. If traffic noise masks their calls, it could affect various aspects of their lives, including territory defense, pair coordination, and warning others of danger. While the exact reasons for the reduced calling are unclear, gibbons may be adapting by singing earlier or adjusting their vocalizations in response to traffic noise.

This study highlights that even when forests remain, the surrounding noise from roads and development can alter the acoustic environment, which is crucial for the communication and survival of wildlife, including the endangered white-handed gibbon.