Researchers have discovered that sperm whales in the eastern and western Mediterranean use distinct click patterns, or dialects, to communicate. The study, published in Proceedings of the Royal Society B, analysed recordings from 2003 to 2021 around the Hellenic Trench near Greece and the Balearic Islands off Spain.
Sperm whales communicate using sequences of clicks called codas, with rhythmic patterns varying between matriarchal groups. These dialects help form social structures, as whales only associate with others sharing the same dialect. The findings suggest that Mediterranean sperm whales, an endangered population of a few thousand, first settled in the west before spreading east and developing a faster dialect.
Dr Luke Rendell of the University of St Andrews, a co-author, noted that the study provides the first clues into how new sperm whale dialects arise. The process appears slow and requires isolation between populations, similar to cultural evolution in human languages and birdsong. While whales in the west favoured a 3+1 coda pattern, those in the east used a faster version, though some overlap occurred.
