According to a study published in the journal Current Biology, the vocal lip-smacks that wild gelada monkeys (Theropithecus gelada) use in friendly encounters have striking similarities to human speech. A family group of geladas (Dave Watts / CC BY 2.0) The geladas, which live only in the high mountain meadows of Ethiopia, are the only non-human primate known to communicate with such a speech-like rhythm. Calls of other monkeys and apes are typically...
