2023 Author: Bryan Walter | [email protected]. Last modified: 2023-05-21 22:24
Scientists for the first time analyzed the complex sound communication of white-handed gibbons and found that these primates, depending on the stimulus, use different variants of the sound "hu". The research results are published in BMC Evolutionary Biology.
White-armed gibbons are known for their loud and attention-grabbing songs. However, they are also capable of producing quiet sounds that are almost indistinguishable to the human ear and are difficult to record and analyze.
Researchers have found a relationship between the stimulus and the sound that the gibbon makes. Subtle differences in audio signals allow gibbons to identify different types of predators, to report found food and the appearance of neighbors.
"The vocalization features of gibbons are of great interest for investigating the evolution of vocal communication in lower primates and possibly the evolution of human communication," explains Dr. Esther Clark, lead author of the study.
Scientists spent about four months observing groups of gibbons in forests in northwestern Thailand. More than 450 variants of the "hu" sound were selected from the collected recordings. Using stepwise discriminant analysis, the researchers established a relationship between audio signals and the conditions under which these signals were recorded.
The beeps to indicate the presence of predators were short and in the frequency range below one kilohertz. Primates used very similar sounds to refer to tiger and leopard. This suggests that gibbons perceive these predators as belonging to the same class of "big cats".
The researchers believe that this work is directly related to the ongoing discussion about the origin of human speech, since it is the ability to reproduce stimulus-dependent sound signals that is critical for attracting the attention of a relative to an external event.