by Wild African elephants may address each other using individual calls that are similar to the personal names used by humans, a new study suggests.
Although dolphins are known to call each other by imitating the signature whistle of the dolphin they want to address, and parrots have been found to address each other in the same way, African elephants in Kenya may step longer to recognize each other.
These elephants learn, recognize and use individual calls like names to address others of their kind, apparently without using imitation, according to the study published Monday in the journal Nature Ecology and Evolution.
The most common type of elephant call is rumble, which has three subcategories. So-called contact roars are used to call another elephant that is far away or out of sight. Blessing rumbles are used when another elephant is within touching distance. A juvenile or adult female uses caregiver rumbles toward a calf she is caring for, according to the study.
The researchers looked at these three types of rumbles, 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 and Buffalo Springs National Reserves between 1986 and 2022 All the elephants could be identified individually by the shape of their ears, as they were continuously monitored for years, according to the study.
The idea was that “if the calls contained something like a name, you should be able to figure out who the call was directed to just from the acoustic features of the call itself,” said lead study author Mickey Pardo, an animal behaviorist and postdoctoral fellow at Cornell University in New York.
The researchers found that the acoustic structure of the calls varied depending on who the target of the call was.
The machine learning model correctly identified the recipient of 27.5% of the calls analysed, “it may not look like much, but it was much more than the model would have been able to do if we had just given him random data,” Pardo told CNN.
“So it suggests that there is something in the calls that allows the model to identify who the intended recipient of the call is,” he said.
The researchers also found that it was unlikely that the elephants were just imitating the voice of the individual they were facing. By comparing pairs of calls between callers and receivers, as well as receivers’ calls to other individuals, they found that most calls made by the caller were no more similar to the receiver’s call than when they addressed individuals other, according to. the study.
The researchers then returned calls to 17 elephants to see if they recognized and responded to the ones originally directed at them.
They found that the elephants would respond more strongly to a call sent to them first than to a call from the same caller sent to someone else first. “That allowed the elephants to tell if a call was meant for them just by hearing that call,” said Pardo.
He also said that the study tells us something about the cognitive abilities of elephants because if elephants are facing each other in this way, they are basically coming up with names for each other. That suggests some capacity for abstract thought – they have to be able to learn this arbitrary sound and associate it with other individuals and basically call each other by name.”
The evolution of language
Elephants maintain various social bonds throughout life with many individuals and are often separated from their close social partners, according to the study.
Thus, some calls may be used to attract the attention of a distant individual, whereas near-distance calls may be used to strengthen social bonds, such as when individuals respond more positively and cooperative when someone remembers his name, the researchers said. .
When elephants were close to each other, care rumbles were more likely to be correctly classified by the machine learning model than greeting rumbles. The researchers suggested that caregivers could use names more often with their calves to comfort the calf or help it learn its name.
Calls from adult females were also classified more accurately than calls from juveniles, suggesting that adult females may use names more in their calls because the behavior takes years to develop, according to the studies.
Pardo said most mammals can’t actually produce new sounds — an ability needed to label something with a name.
He added that since humans, dolphins and elephants address individuals in their species with something like a name, “the need to name others may have had something to do with the evolution of language.”
“Perhaps it is this pressure of all these complex social relationships – and you need to be able to face other people as individuals – that made animals, including our own ancestors , develop this ability to associate new sounds with new objects. That is how language may have originated,” continued Pardo.
The study authors were unable to definitively determine whether different elephants used the same name to refer to the same person, or whether they addressed the same person by different names.
They were also unable to determine which aspects of the calls were their names, and information such as the identity, age, sex and emotional state of the caller were encoded in their characteristics, according to the study.
Pardo said he would like to figure out “how these calls are named, and be able to isolate the names to specific individuals, and then I think that would open up a lot of other areas of inquiry. “
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