Figure 1. Representative spectrogram showing a duet song in southern yellow-cheeked gibbons (Nomascus gabriellae). During the build-up phase of the female great call (red square) in duet song, the ...

Alex Dunkel (Maky), CC BY 3.0 https://creativecommons.org/licenses/by/3.0, via Wikimedia Commons Primate is a group of mammals that includes monkeys, humans, tarsiers ...