A bizarre sound made by a primate could help to reveal more about the origins of human speech, a study suggests. Scientists have found that the gelada, a species that is closely related to the baboon, makes a gurgling noise that shares features with human language.
They believe the monkey's call could be similar to the primitive noises that the evolutionary ancestors of humans once made. The study is published in the journal Current Biology.
The lead author Dr Thore Bergman, from the University of Michigan in the US, said: "Geladas make vocalisations that have some speech-like properties - it's the first time that that has been shown in a non-human primates."
The call of the gelada, which is found in the highlands of Ethiopia, sounds like a cross between a yodel and a baby's gurgle. To create sounds of such complexity is unusual in the primate world. Monkeys and apes, in general, can only make the most basic noises.