Gibbons whisper to communicate information secretly
It has been found that apes also whisper like humans in order to give information secretly to others. It has been observed that gibbons do this often to communicate.
The apes make different types of soft calls, called 'hoos', and these are almost inaudible to the humans. This indicates that the quiet calls are used to alert other gibbons in close proximity without alerting others. Scientists studying lar gibbons also found that a different whisper call was used by them, when a tiger or leopard was present in the surrounding area.
According to Dr Esther Clarke, who led the research at the University of Durham, the findings could also assist in providing valuable hints regarding human speech. Clarke added that this could also help know why humans started using whispers.
According to Clarke, "These animals are extraordinarily vocal creatures and give us the rare opportunity to study the evolution of complex vocal communication in a non-human primate. In the future, gibbon vocalisations may reveal much about the processes that shape vocal communication".
Clarke added that as they are an ape species, they could help them trace the evolution of human communication. In the nature, gibbons have one of the loudest calls and they make whoops, which can travel a long distance through the forests where they live. So far, most of research work focused on loud songs that are used by animals in order to communicate with each other over long distances.
The work has been published in the journal BMC Evolutionary Biology. Their study concentrated on the softer hoo call types. The researchers worked for almost four months following lar gibbons around the forests of north east Thailand and Mo Singto in Khao Yai National Park.