New research: When gorillas beat their chests they show how big their body is, assess the fighting ability of rivals and attract mates, according to new research. The sounds the beating makes may also allow individual gorillas to be identified across dense forests, researchers in Germany have found. They say the audio frequencies of the chest beats made by larger males are significantly lower than those made by smaller males, therefore giving clues about body size. Author Edward Wright and his team recorded 25 wild adult male silverback gorillas at Volcanoes National Park in Rwanda. Chest beats were subsequently analysed according to duration, number, and audio frequency. It was found that the chest beats of larger males had lower peak frequencies than smaller ones. Larger males may have bigger air sacs near their voice box, it is believed, which could be lowering the frequencies of sounds they produce while beating their chests. The experts also observed variations in the duration and number of chest beats made by different gorillas regardless of body size. Mr Wright, from the Max Planck Institute for Evolutionary Anthropology in Leipzig, said: "The gorilla chest beat is one of those iconic sounds from the animal kingdom, so it is great that we have been able to show that body size is encoded in these spectacular displays." He added: "This hints at the possibility that chest beats may have individual signatures, but further study is needed to test this." Female gorillas are likely to use the information to find potential mates, it is thought. #gorilla #gorillas #silverback - @endpainproject