The Guardian reports:

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.

“This is a huge number for culturally defined entities outside modern human ethnolinguistic groups,” Whitehead said. The clans might meet but they never interbred, he added. Their sense of identity appeared, in human terms, almost tribal, recognising and maintaining their differences while being of the same species.

Sperm whales have the biggest brains on the planet. The animals can reach 15 metres in length, weigh up to 45 tonnes, and are able to dive for up to two hours in search of food, mostly squid. They are present in oceans around the world.

Whitehead noted that the clans appeared to be “almost entirely female-based”. Males visited females occasionally and for only a few hours at a time. Their “only important transfer is of sperm”. Designated females undertook “alloparental” care, looking out for calves while their mothers dived for food.

While underlining how different whales were from humans, the paper suggested intriguing correspondences. Sperm whale society appeared to use consensus, rather than top-down leadership, to reach communal decisions. [Continue reading…]