A study on elephant communication identifies social information in overlapping vocalizations and opens new questions about how they coordinate life in a group.
How do elephants understand one another when multiple individuals emit sounds simultaneously? Elephant communication poses a fascinating challenge: determining what information persists when everyone is communicating. A study published in Scientific Reports provides new clues for interpreting those choruses and for understanding their relation to group interactions.
Studying these exchanges allows us to explore how bonds are maintained and activities are coordinated among social animals. According to ElephantVoices, a participant in the work, the finding offers a pathway for investigating collective communication, although questions remain about how the elephants themselves interpret these signals.
Drawing on recordings of wild elephants from Amboseli, Kenya, and on machine-learning tools, the article explains how researchers have tackled this puzzle and why understanding the form of animal communication is so important.
La communication de los elefantes
Elephants communicate through low-frequency roars, often imperceptible to human hearing. Now, a team of researchers has found that 60% of these sounds are produced in ‘group choruses’ that carry information about their feelings or actions.
The work, carried out by researchers from Colorado State University (USA) and by the organizations ElephantVoices and Earth Species Project in Amboseli National Park (Kenya), is described this Thursday in the journal Scientific Reports.
Scientists had previously observed that the grunting choruses of African savanna elephants (Loxodonta africana) are especially common during intense social interactions, such as when individuals reunite or coordinate what to do next.
However, analyzing these choruses had been a challenge until now, as they tend to overlap.
To overcome this barrier, the researchers studied 902 recordings of individual and chorus grunts from 84 wild elephants belonging to 39 families in Amboseli National Park. The sounds were collected during three periods spanning roughly four decades: 1986–1990, 1998–2009, 2020 and 2022.
Using machine learning, the researchers were able to show that elephant choruses transmit multiple layers of information at once, including data about the actions that family members are carrying out together.
¿En qué contexto social se producen estos gruñidos?
In total, they examined the roars associated with six different social contexts: roars of contact between separated elephants, roars of ‘let’s go’ associated with attempts to start a group movement, cadence-like roars exchanged during feeding or resting, roars mothers’ cooing to calves, small roars greeting very closely bonded individuals, and roars greeting when they reunite.
First, they found that the behavioral context, both for the individual roars and for the choruses, could be predicted from their acoustic characteristics.
The models trained on individual roars could also predict the context of the chorus roars, which would indicate the existence of common acoustic traits specific to each social situation, such as which frequencies have higher power.
One of the most surprising findings for the researchers was to see that elephant roars became acoustically more similar as the cadence-based exchanges progressed, during feeding or resting, and the contact and greeting roars.
¿Para qué sirve esta convergencia vocal?
Given that cadence-based and contact exchanges typically involve several elephants, the authors suggest that this vocal convergence could help the group decide what to do next.
“For me, this is one of the most exciting outcomes of our study. We have known for years that elephants are capable of learning to emit sounds, which means they can learn to modify their vocalizations in response to what they hear,” says one of the authors, Michael Pardo, senior researcher at ElephantVoices in a statement from the organization.
“Our finding of rapid vocal convergence during certain choruses offers an example of on-the-fly vocal learning among wild elephants,” he adds.
The study, however, has not included playback experiments to test how elephants respond to convergent calls.
“We have shown that elephant choruses, far from being a muddle of sounds, contain information about the social context and, during some exchanges, the voices of the participants become acoustically similar,” concludes another author, Joyce Poole, Chief Scientist of ElephantVoices.
The methods of this research, according to the authors, offer a way to listen to the chorus as a whole, opening a new avenue to study coordinated vocal signals in elephants and in other social species that communicate in a similar way, such as chimpanzees or sperm whales.
