African elephants address one another with individually specific name-like calls

Area of Science:

• Animal Behavior
• Bioacoustics
• Evolutionary Biology

Background:

• Human language uniquely uses non-imitative names, expanding expressive power.
• While some animals like dolphins and parrots use calls for individual recognition, it often involves imitation.
• The evolutionary origins of non-imitative naming remain largely unexplored in the animal kingdom.

Purpose of the Study:

• To investigate whether African elephants use individually specific calls to address conspecifics.
• To determine if elephant addressing calls rely on imitation of the receiver's vocalizations.
• To explore the implications of non-imitative addressing for understanding language evolution.

Main Methods:

• Utilized machine learning to analyze acoustic structures of elephant calls and predict the intended receiver.
• Conducted playback experiments presenting elephants with calls addressed to them versus calls addressed to others.
• Compared elephant responses to playback stimuli to assess their recognition of addressed calls.

Main Results:

• Machine learning models accurately predicted call receivers based on acoustic features, independent of receiver vocalizations.
• Elephants showed differential responses to playback calls, reacting more strongly to calls originally addressed to them.
• Evidence suggests elephants address individuals with specific calls, likely without imitating the receiver's sounds.

Conclusions:

• Wild African elephants possess a system of individually specific addressing calls.
• Elephant addressing behavior appears to be non-imitative, distinguishing them from other known species.
• This finding has significant implications for understanding the evolution of complex communication and naming.