Dynamic, Interactive Vocal Fold ControlIn a study published last year an adolescent male orangutan achieved a milestone in vocal control never before performed by any great ape, including chimpanzees. As the study reported:
These results confirm the capacity of orang-utans to learn and acquire new calls into their individual repertoires, both in the form of voiceless consonant-like calls and voiced vowel-like calls.
This has “never been demonstrated directly in a non-human primate.” That includes chimpanzees.
Perhaps a chimp will someday exhibit the same skill, but that has yet to be seen. We suspect there is a reason why this finding involved an orangutan. It is another example of their relatively advanced abilities.