African elephants' overlapping rumbles carry information about the social situation in which they call. A new study of wild females in Kenya also found that sounds became more similar during some exchanges, including contact and greetings. The work brings group choruses into a field that has largely concentrated on individual calls, while separating acoustic information from proof of how elephants respond.
When African savannah elephants call together, the overlapping sound still carries information about their social situation. A study published on October 1 examines these group choruses among wild females in Amboseli, Kenya. It found acoustic patterns associated with contact, movement coordination and greetings, adding simultaneous calls to a research field that has largely studied one voice at a time.[1], [2]
Researchers compared 902 examples of single calls and overlapping choruses across six behavioral contexts. The analysis used collective acoustic features where the callers' individual voices could not be fully isolated. Computer classifications performed better than chance in identifying the context, although incorrect assignments outnumbered correct ones. The calls' structure therefore retained useful distinctions while several social situations also overlapped acoustically.[1]
Some successive exchanges showed acoustic convergence: later calls became more similar to earlier ones. Contact and greeting exchanges were among those examples. Calls also varied among animals and family groups; differences between families could reflect the voices of particular individuals. The study did not use playback experiments to measure the elephants' responses, leaving the behavioral effect of the sounds separate from the information present in them.[1]
