Researchers from CSU, Save the Elephants and ElephantVoices used machine learning to confirm that elephant calls contained a name-like component identifying the intended recipient, a behavior they suspected based on observation. When the researchers played back recorded calls, elephants responded affirmatively to calls that were addressed to them by calling back or approaching the speaker. Calls meant for other elephants received less of a reaction.

"Dolphins and parrots call one another by 'name' by imitating the signature call of the addressee," said lead author Michael Pardo, who conducted the study as an NSF postdoctoral researcher at CSU and Save the Elephants, a research and conservation organization based in Kenya.

"By contrast, our data suggest that elephants do not rely on imitation of the receiver's calls to address one another, which is more similar to the way in which human names work."

The ability to learn to produce new sounds is uncommon among animals but necessary for identifying individuals by name. Arbitrary communication—where a sound represents an idea but does not imitate it—greatly expands communication capability and is considered a next-level cognitive skill.