Mother and calf sperm whales (Photo by Gabriel Barathieu, CC BY-SA 2.0 <https://creativecommons.org/licenses/by-sa/2.0>, via Wikimedia Commons)

Dear Readers, after my sperm whale adventures a few weeks ago I was very excited to read an article in New Scientist which suggested that the language of sperm whales could be the closest yet found to human language. But how so?

Sperm whales are long-lived, social animals, who communicate with one another using clicks. They also use these clicks to echolocate, much as bats do – they dive down into the blackness of the deep abyss (up to 2 km down) to hunt their prey, the giant squid. However, until recently scientists were bemused as to how the clicks were used. A study by Daniela Rus at Massachusetts Institute of Technology recorded over 9000 calls from a population of sperm whales in the Eastern Caribbean (small devices were attached to the whales using suction cups).

Here is the sound of a sperm whale hunting for prey. Note the regularity of the clicks.

And here is a sperm whale homing in on its prey – note how the clicks merge together to form what’s known as a ‘creak’.

Incidentally, the clicks of a sperm whale can be up to 230 decibels, making the sperm whale the loudest animal in the world. Some people believe that sperm whales might stun their squid prey, just as some bats ‘shout’ at moths in order to knock them out. There seems to be no truth to the idea that a sperm whale ‘shout’ has ever damaged a human diver, however, in spite of some stories about such things.

The scientists, however, are interested in the social calls that sperm whales make. These are called ‘codas’ – there are 18 of them, each comprising a particular click pattern.

What fascinated the scientists was that these basic codas can be amended by adding an extra click to the beginning or end – this seemed to be a signal to the listening whale that it was time to ‘speak’. The codas can be combined and recombined in different ways, and can also be sped up or slowed down. The  scientists have actually drawn up a ‘sperm whale phonetic alphabet’, though we are a long way from understanding exactly what a particular combination of codas means.

It’s clear that there is much yet to be discovered about sperm whale communication, but this is a fascinating insight into the sheer complexity of the sounds that they make, and the possible meanings that might be encoded. What conversations are they having, I wonder? I cannot begin to imagine how different the undersea world of the sperm whale is, but learning about their language makes me think that there are dimensions that we haven’t even begun to contemplate.

Sperm Whale off the coast of the Azores, Portugal (Photo by Szecska at https://www.flickr.com/photos/szecska/8986104296)