Bonobos, our closest animal relatives, have been filmed for the first time appearing to "say no" by shaking their heads.
Published: 6:28PM BST 05 May 2010
The apes were captured by scientists moving their heads from side to side as they stopped others from performing a task they were not happy with.
In one film a mother is seen shaking her head to stop her infant climbing a tree. In another, a bonobo shakes its head at a colleague trying to steal its food.
Researchers believe that the behaviour may be an early precursor to head-shaking behaviour among humans.
"In bonobos, our observations are the first reported use of preventive head-shaking," said Ms Christel Schneider from the Max Planck Institute, Germany.
Ms Schneider said the videos captured at Leipzig Zoo in Germany show a bonobo mother shaking her head in disapproval when her infant plays with some food.
"Ulindi, tried to stop her infant, Luiza, from playing with a piece of leek," she said.
"Since Luiza took no notice despite repeated attempts to stop her, Ulindi finally shakes her head towards the infant."
Ulindi eventually throws the leek away whilst the infant still tries to reach for it, the researchers report.
African great apes such as bonobos (Pan paniscus) and chimpanzees (Pan troglodytes) are known to use head gestures such as nodding, bowing and shaking to communicate with other group members.
Bonobos are already known to use head-shaking to initiate interactions with other members of the group, such as playing.
However, this is the first study to film and observe an ape shaking its head in a negative context to stop or prevent other bonobo behaviour.
The scientists observed the behaviour whilst studying bonobos as part of wider study on the communication of great ape infants.
Using video recordings they studied the gestures and behaviour of bonobos, chimpanzees, gorillas and orang-utans in six European zoos.
During the study, they witnessed four individual bonobos shaking their heads in this way on 13 different occasions.
Previously only anecdotal reports have noted individual chimpanzees shaking their head to signal 'no'.
The researchers, who published their findings in the journal Primates, believe that bonobos use a wide range of head gestures compared to chimpanzees, and are considered to be more sophisticated at using their head to signal meaning.
Such sophisticated communication systems may emerge because of the apparently tolerant, co-operative and egalitarian societies that bonobos live in, with their diffuse hierarchies and complex social structures.
In this way, bonobos may have developed the preventive head-shake to say "no" and negotiate conflict situations.
The researchers are cautious to say that they cannot be sure the bonobos definitively mean "no" when they shake their heads this way.
No comments:
Post a Comment