An analysis of the sound created by hyenas has uncovered the information behind the ‘laughing’ sound that they make. Experts found that these animals use the sound to declare dominance, as well as identity and age.
Nicolas Mathevon of the Université Jean Monnet in St. Etienne, France, and Frédéric Theunissen of the University of California in Berkeley, USA, along with a group of researchers, carried out an investigation on the animals at a station in Berkeley.
“The hyena’s laugh gives receivers cues to assess the social rank of the emitting individual. This may allow hyenas to establish feeding rights and organise their food-gathering activities”, said Theunissen.
He and his colleagues found that the changing note frequency of the sound reveals a subordinate or a dominant status, while its pitch encodes information about age. Such vocalisation can be heard especially when the animals spot food. Their hierarchy dictates who gets the package and who submits themselves to others’ authority.
The team also says that the sound may also be a means by which hyenas seek help or express grief during an unpleasant event.
Explaining how forming allies serve beneficial to hyenas, Theunissen explained: “Lions often eat prey previously killed by hyenas. A solitary hyena has no chance when confronted by a lion, whereas a hyena group often can ‘mob’ one or two lions and get their food back. Giggles could therefore allow the recruitment of allies. Cooperation and competition are everyday components of a hyena’s life”.
Theunissen and his team are planning to conduct more field investigation on the sound created by the animals.
