Sperm Whales in Eastern Mediterranean Develop Distinct Dialect

A study published in June in Proceedings of the Royal Society B: Biological Sciences reveals that sperm whales in the eastern Mediterranean have developed a distinct dialect from those in the west. Researchers analyzed 5,291 codas recorded between 2003 and 2021 and found that whales near the Hellenic Trench off Crete, Greece, use a faster version of the typical "3+1" coda (three clicks, pause, fourth click) used by whales near Spain's Balearic Islands. The western dialect is used exclusively by western whales, while eastern whales mostly use their own dialect but occasionally switch to the western one. Sperm whales entered the Mediterranean via the Strait of Gibraltar about 20,000 years ago and are now a genetically distinct, endangered subpopulation with 250 to 2,500 mature individuals. The eastern dialect likely evolved slowly over hundreds or thousands of years. Study co-author Txema Brotons of the Tursiops Association notes that this shows cultural traditions are passed down among whales, similar to human cultures. The findings offer insights into language evolution in non-human animals.