The vocal patterns of gelada monkeys have been found to bear similarities to human speech.
The lip-smacking vocalising of the geladas has been found to closely mirror the rhythm and pacing of syllables spoken by humans. No other primate has been shown to use such rhythmic vocalisation, with peaks and valleys in their speech patterns that closely resemble the gaps in syllables.
Scientists are investigating if these vocalising patterns have any specific meaning in geladas communities or if they could even be a precursor to more discernible speech.
Read more at University of Michigan