Sperm whale chatter is so complex they have their own alphabet
Sperm whales have the biggest brain on the planet and, it seems, they are putting it to good use.
Scientists have discovered that their communication may be much more complex than initially thought, and they can have a range of different conversations using their own ‘alphabet’ of clicks.
Communication is important for the social animals to help make group decisions and coordinate joint tasks, such as foraging and rearing young.
Sperm whales combine and modulate different clicks and rhythms, known as codas, to create complex calls, similar to human language.
Previous research suggests that sperm whale codas help them communicate their identity, but little else was understood about their communication system.
Now, Pratyusha Sharma and her colleagues have used data from the Dominica Sperm Whale Project to analyse recordings from 60 different whales from the Eastern Caribbean sperm whale clan to create a ‘sperm whale phonetic alphabet’.
They found that the whales’ communication system is more complex and has a greater capacity for sharing information than previously thought, as the combination and structure of the sequences depended on the conversational context of the individuals.
The researchers also managed to identify a ‘combinatorial structure’ to the whales’ language, where they can combine and modulate different clicks and rhythms to create complex vocalisations. This greatly increases their range of conversation – like putting different letters together to form different words, or adding extra letters to change the meaning, such as content and discontent.
The researchers wrote: ‘Sizable combinatorial vocalisation systems are exceedingly rare in nature.
‘However, their use by sperm whales shows that they are not uniquely human, and can arise from dramatically different physiological, ecological, and social pressures.’
So far, this duality of patterning – where speech can be analysed on two levels, both the sounds of the letters individually and combined into full words or added as prefixes or suffixes – has only been found in human communication.
However, while the functions and meaning of the click commendations are still unknown, the researchers suggest that the sperm whale language is capable of representing a large number of possible meanings.
The research is published in the journal Nature Communications.