New york (MOL): Chimpanzees bash out distinctive drum solos on the roots of trees as a form of ‘signature’ and to tell others in their group where they are. Biologists studying the primates have found over the years that male chimps grip the buttresses of tree roots with their hands and beat them with their feet. The noises produced - which is normally accompanied with loud hooting -  are known as pant calls, and can be heard more than half a mile (1km) away, even in the dense jungle. But now one group of scientists have found that this drumming contains distinctive rhythmic patterns that can be used to identify a specific individual.