Wild African elephants address each other with name-like calls, scientists have discovered.
Some other species of the animal kingdom such as dolphins and parrots call one another by imitating the signature sound of the receiver. But that is not the mechanism adopted by elephants, researchers wrote in a new paper. Rather, they use specific vocalisations for addressing each other, they noted. The pachyderms also displayed evidence of recognising and reacting to these calls.
The findings of the study were published in the journal Nature Ecology and Evolution.
Researchers from Colorado State University, Save the Elephants and Elephant Voices recorded rumbles and as well as contact and greeting calls recorded between 1986 and 2022 of two African elephant herds from Samburu in northern Kenya and Buffalo Springs National Reserves in Amboseli National Park in southern Kenya.
They used artificial intelligence to find evidence of a name-like component in elephant calls – a common elephant low frequency but harmonically rich sound that is unique and distinguishable.
They shortlisted 469 distinct calls that included 101 elephants calling to address 117 receiving individuals. They noticed that such calls were made when the caller was out of sight for more than 50 metres from one or more social herd and an effort to re-establish contact.
Greeting rumbles or calls were made when one individual approached the other within touring distance, according to the researchers. They also noticed caregiving calls between an adult and a calf.
“Inventing or learning sounds to address one another suggests the capacity for some degree of symbolic thought,” the researchers added.
They also observed that elephants responded actively to playback of calls addressed to them against the playback of calls from the same caller addressed to a different receiver. This means that the calls had receiver-specific information embedded in them, prominent to elephants or conspecifics.
Like humans, elephants maintain lifelong differentiated social bonds within the community. Vocal contact calls enabled them to reconnect with elephants where the caller and receiver were separated, the researchers wrote.
In case of close-distance calls such as greeting and caregiving rumbles, vocal labels may help strengthen social bonds, similar to the way in which humans experience a positive affective response and increased willingness to cooperate when someone remembers their name, they noted.
Explaining the behaviour further, the researchers said the surprising finding for them was how caregiving rumbles were more than just greeting rumbles.
They said that labels possibly are included in caregiving rumbles to enable calves to learn them, which others use to address them or because hearing the specific label was more comforting for calves.
“Calls made by adult females were also more likely to be correctly classified than calls made by juveniles. This suggests that adult females may use vocal labels more than calves, possibly because the behaviour takes years to develop,” the researchers stated in the report.
They found that elephant rumbles are highly complex with multiple encoded messages but not limited to caller identity, age, sex, emotional state and behavioural context.
It suggested that vocal labels contributed to a small fraction of the total variation in calls, even though the information above was encoded in voice characteristics. On the contrary, human language includes sequential encoding information to convey complex messages.
“Elephants may rely more on simultaneous encoding, packing more information into a single vocalisation than humans typically do,” it said.
The researchers also made an elephant listen to recorded sounds with specific frequencies of their friend or family members, to which it responded positively.
Lead author Michael Pardo and postdoctoral associate, K Lisa Yang Center for Conservation Bioacoustics Cornell Lab of Ornithology, said, “We don’t know if their names function exactly like human names, but I think we have found pretty strong evidence that they do have something like a name.”
In an email conversation, he added, “Unfortunately, we were not able to definitively isolate the names for specific individuals, as the names are likely only one component among many in the calls, and we don’t yet know how to tease apart all the different messages encoded in a single call.”
“But when we played back calls that we thought were names, the elephants responded more strongly to what we believed to be their own name compared to what we believed to be someone else’s name,” he said.
The study noted that the findings prove that after humans, elephants are now known to have made use of arbitrary labels like names.
Arbitrary communication is when a sound represents an idea but is non-imitating in nature. It enables communication ability and considers higher levels of cognitive skill.
“The use of learned arbitrary labels is part of what gives human language its uniquely broad range of expression. Our results suggesting possible use of arbitrary vocal labels in elephants provide an opportunity to investigate the selection pressures that may have led to the evolution of this rare ability in two divergent lineages,” the authors noted.
They said that these findings now raise further curiosity on the complexity of elephant social cognition, given their potential relevance of symbolic communication related to their social decision making.
We are a voice to you; you have been a support to us. Together we build journalism that is independent, credible and fearless. You can further help us by making a donation. This will mean a lot for our ability to bring you news, perspectives and analysis from the ground so that we can make change together.
