Sperm whales live in clans with distinctive cultures, much like those of humans, a study has found.

Using underwater microphones and drone surveys, Hal Whitehead, a sperm whale scientist at Dalhousie University, in Halifax, Canada, examined the sounds the animals made and their feeding habits and found they organised themselves into groups of up to around 20,000.

The paper, published in the Royal Society Open Science journal, said the clans were defined by variations in their vocalisations – distinctive, morse code-like sequences of clicks known as “codas”.

Acting like human dialects, these enabled Whitehead and his colleagues to establish the existence of seven such clans in the Pacific Ocean – with a total of 300,000 sperm whales.