Sperm whales, known for their intricate social structures and communication abilities, have recently been the focus of groundbreaking research shedding light on the complexity of their vocalizations. Traditionally recognized for their clicks, termed codas, scientists have delved deeper into understanding the structure and nuances of these sounds.
Living in pods of around 12-20 animals, and relying on communication for various social interactions, sperm whales employ codas to convey messages within their groups. Previous knowledge suggested that these clicks facilitated identification of the speaker and showcased dialectical differences among whale clans. However, recent studies have uncovered a much richer layer of complexity within sperm whale communication.
“Investigating a dataset collected across over a decade of nearly 9,000 codas from the sperm whale families of the Eastern Caribbean clan, our results show that these whales have a more complex combinatorial communication system that demonstrates rubato and ornamentation, in which whales make sub-second adjustments to match one another as they converse and add extra clicks to known coda types depending on the context within their conversations,” said Dr Shane Gero, Biology Lead of Project CETI and co-founder of the Dominica Sperm Whale Project, in statement sent to IFLScience.
Researchers, led by Dr. Shane Gero, analyzed a vast dataset spanning nearly a decade and comprising nearly 9,000 codas from the Eastern Caribbean clan of sperm whales. Through meticulous examination, they identified distinct variations in coda structure, incorporating musical concepts such as rubato and ornamentation, alongside rhythm and tempo. This discovery led to the formulation of a “sperm whale phonetic alphabet,” elucidating the intricate combinations through which these creatures convey information.
The team found that sperm whale communication involves a sophisticated system of turn-taking and simultaneous production of codas, with whales exhibiting control over coda length and the incorporation of additional clicks or modifications to suit conversational contexts. This intricate web of communication suggests a much deeper level of complexity than previously understood, with potential implications for the whales’ social dynamics and cognitive abilities.
“This study defines previously unknown structures in their coda exchanges. It greatly expands the potential ‘encoding space’ or ‘expressivity’ within their coda exchanges. While we don’t know the function or meaning of these new features, it opens up the possibility that we might start to find structures and features that were once thought to only belong to humans,” Gero told IFLScience.
“We have not yet looked for these features in other clan’s coda exchanges. However, what we have documented here appear to be structures that are likely to be a part of the communication system for all sperm whales,” Gero said. “It may be that one clan makes more dramatic rubato, or perhaps only rarely uses ornaments compared to other clans; but we don’t yet know.”
While the study primarily focused on the Eastern Caribbean clan, researchers speculate that similar communication structures likely exist across different clans of sperm whales. However, further investigation is required to ascertain the universality of these findings.
“Understanding structure is the first step, the next would be to combine this with an understanding of context, both behavior (what they are doing when we find ornaments, for example) and social context (who they are with when rubato varies the most? Is it with mom-calf, or two sisters, or correlated with kin relatedness, for example),” Gero told IFLScience.
The significance of this research extends beyond mere understanding of whale communication. It opens avenues for exploring the parallels between sperm whale vocalizations and human language. The presence of a combinatorial coding system akin to human speech suggests a potential convergence in communication patterns between species. This phenomenon, known as duality of patterning, wherein meaningless elements can be combined to form meaningful utterances, has previously been exclusive to human language.
“We do suggest that this combinatorial system we document in sperm whales opens up the possibility that sperm whale communication might provide our first example of duality of patterning in another species outside of humans. The phenomenon that small meaningless parts can be combined into meaningful wholes, which could then be combined into meaningful utterances like sentences,” he said.
The research team’s next step involves connecting the identified features of coda communication with behavioral contexts, thus unraveling the meaning behind these intricate vocalizations. By decoding the nuances of sperm whale communication, scientists aspire to delve deeper into the social dynamics and cognitive capacities of these mysterious beings.
Essentially, this research sheds light on the previously unknown complexity of sperm whale vocalizations, revealing a sophisticated communication network that mirrors the structural intricacies of human language.