Clicks instead of words
Sperm whales communicate with sequences of clicks called codas: usually 3 to 12 clicks in fixed patterns. They exchange them when socialising or between long dives. Until now, it was mainly known that some codas reveal who is calling.
Your guess
The data had been sorted into 21 coda types. How many common combinations were found?
Rhythm, tempo – and ornaments
A team from MIT and Project CETI found two new features, "rubato" and "ornamentation". They change with the flow of the conversation, and the whales imitate them from each other. Together with rhythm and tempo they make up a large repertoire – the team calls it a "sperm whale phonetic alphabet".
What's still open
What many codas mean is still unknown. The recordings come from a clan in the eastern Caribbean, collected by the Dominica Sperm Whale Project. Sperm whales, by the way, have the largest brain on Earth, more than five times as heavy as ours.
