Elephants use names to call each other, study suggests

Elephants African savages can communicate with each other using individualized calls that resemble the personal names used by humans, a new study suggests.

While dolphins are known to call each other by imitating the characteristic whistle of whoever they want to call and parrots have been found communicating in a similar way, African elephants in Kenya can go a step further in identifying each other.

According to the study published this Monday (10) in the journal Nature Ecology and Evolutionthese elephants learn, recognize, and use individualized name-like calls to communicate with others of their species, apparently without using imitation.

The most common type of call from these animals is a snort, which has three subcategories. Contact sounds are used to call another elephant that is far away or out of sight. Greetings are used when another elephant is within touching distance. Caretaker calls are used by an adolescent or adult female toward a cub she is caring for, according to the study.

The researchers analyzed these three types of snoring using a machine learning model to analyze recordings of 469 calls made by wild groups of females and cubs in Amboseli National Park and Samburu National Reserves, both in Kenya, and Buffalo Springs in the United States. United States, between 1986 and 2022. All elephants could be identified individually by the shape of their ears, as they had been monitored continuously for decades, according to the research.

The idea was that “if calls contained something like a name, then it should be possible to figure out who it was directed at just by the acoustic characteristics of the sound itself,” said Mickey Pardo, lead author of the study, animal behaviorist and postdoctoral fellow at the University of California. Cornell in New York, United States.

The researchers found that the acoustic structure of the calls varied depending on who the recipient was. The machine learning model correctly identified the recipient of 27.5% of the sounds it analyzed, “which may not sound like much, but it was significantly more than the model would have been able to do if we had just fed it random data,” Pardo said. to CNN.

“This suggests that there is something about the calls that allows the model to identify who the intended recipient was,” he added.

The researchers also found that the elephants were probably not just imitating the voice of the individual they were addressing. By comparing pairs of calls between senders and receivers, as well as the receivers’ signals to other individuals, they found that most vocatives made by the sender sounded no more similar to the receiver’s call than when they were addressed to other individuals, according to the study.

The researchers then played calls to 17 elephants to see if they recognized and responded to the calls that had originally been directed at them.

They found that elephants responded more strongly to a sound that had originally been directed at them than to a vocative from the same speaker that had originally been directed at someone else. “So this means that elephants could tell whether a call was intended for them just by hearing it,” Pardo said.

He added that the study “tells us something about the cognitive abilities of elephants because if elephants are addressing each other in this way, they are basically creating names for each other. This implies some capacity for abstract thought — they need to be able to learn this arbitrary sound and associate it with other individuals and, essentially, call each other by name.”

The evolution of language

Elephants maintain varied and long-lasting social bonds with many individuals and are often separated from their closest social partners, according to the study.

Thus, some calls can be used to get the attention of an individual who is far away, while short-distance calls can be used to strengthen social bonds, similar to human behavior, which responds more positively and cooperatively when someone remembers its name, the researchers said.

When elephants were nearby, grooming rumbles were more likely to be classified correctly by the machine learning model than greeting rumbles. The researchers suggested that caregivers may use names more frequently with their puppies to comfort them or to help them learn their vocative.

The calls of adult females were also classified more correctly than those of juveniles, suggesting that adult females may use names more frequently because the behavior takes years to develop, according to the study.

Pardo said most mammals aren’t actually capable of learning to make new sounds — a skill needed to label something with a name. He added that since humans, dolphins and elephants address peers of their species with something resembling a name, “the need to name other individuals may have had something to do with the evolution of language.”

“Maybe this pressure of having all these complex social relationships — and the need to be able to address others as individuals — is what led animals, potentially including our own ancestors, to develop this ability to associate new sounds with new things. That could be what led to language,” continued Pardo.

The study authors were unable to conclusively determine whether different elephants used the same name to refer to the same individual, or whether they addressed the same individual with different calls.

They also were unable to determine which aspects of the sounds constituted the name, with the calls also containing information such as the sender’s identity, age, gender and emotional state encoded in their characteristics, according to the study.

Pardo said he would really like to find out “how these calls actually contain a name and I would like to be able to isolate the names to specific individuals, so I think that would open up a lot of other areas of investigation.”

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