Mediterranean sperm whales. Pelagos Institute

Much like human languages, the vocalizations of sperm whales evolve over time, as disparate populations of whales develop distinct dialects. A new study shows how an isolated population of sperm whales in the eastern Mediterranean developed its own dialect based on vocalizations used by other whales.

The patterns of clicks issued by sperm whales identify them as part of different “vocal clans.” Scientists previously thought that all Mediterranean whales were part of the same clan, which was distinguished by a repeated vocal pattern: three clicks, a short pause, and then a fourth click.

Analyzing 20 years of audio recordings of whales across the Mediterranean, scientists found that sperm whales in the Hellenic Trench, near Greece, produced a faster form of this call than did whales around the Balearic Islands, between Gibraltar and Italy. However, researchers found, the eastern whales would sometimes revert to the older, western dialect.…