Dilara Hamit
24 June 2026•Update: 24 June 2026
Sperm whales living on opposite sides of the Mediterranean have developed distinct vocal "dialects" similar to regional accents in human speech, according to a new study.
Researchers found whales in the eastern and western Mediterranean communicate using different rhythmic patterns of clicks, known as codas, suggesting vocal traditions can evolve as populations become separated over time.
The findings, published in the journal Proceedings of the Royal Society B, provide rare insight into how new dialects emerge within animal societies.
Sperm whales communicate through sequences of clicks, but the timing and rhythm of those clicks can vary between social groups. These dialects help define so-called "vocal clans," with whales typically associating and cooperating only with others that share the same vocal patterns.
"The dialect is used to form social structures, within which these animals will cooperate," said Luke Rendell of the University of St Andrews, a co-author of the study.
The researchers analyzed underwater recordings collected over 112 days between 2003 and 2021 near the Hellenic Trench off Greece and around Spain's Balearic Islands.
While whales in both regions commonly used codas consisting of four clicks, the study found clear differences in their rhythm. Western Mediterranean whales favored a pattern featuring three evenly spaced clicks followed by a pause and a final click, while eastern whales tended to produce a faster variation of the same sequence.
Researchers also found some overlap, with eastern whales occasionally using the western dialect.
The team believes the findings support the idea that sperm whales first established themselves in the western Mediterranean before spreading eastward, where their vocalizations gradually evolved into a distinct dialect.
According to the study, the results suggest dialect formation is a slow process that requires at least some degree of separation between populations. Similar patterns have been observed in human language and birdsong.
Scientists said the discovery offers one of the clearest examples yet of how new whale dialects may emerge.
The Mediterranean sperm whale population is considered endangered and is estimated to number only a few thousand individuals. Researchers believe the whales first entered the Mediterranean around 20,000 years ago and have remained largely isolated from other sperm whale populations.
The study adds to growing evidence that sperm whale communication shares important similarities with human language, reinforcing the view that culture and learned behaviors play a significant role in the social lives of the ocean's largest predators.
