Sperm whale 'dialects' linked to distinct cultures

Sperm whalesspeak indistinct regional dialects that appear closely linked to different "cultural groups," a Canadian researcher says.

"The animals in the Caribbean sound different than the animals in the Pacific even the Gulf of Mexico, which is right beside the Caribbean," said Shane Gero, a researcher at Dalhousie University in Halifax. "In a lot of ways, that's very similar to us. We can identify someone from the U.K. versus Canada because they say 'lorry' and not 'truck.'"

Sperm whales from many different regions meet in some "multicultural" areas of the ocean but tend to associate with whales that speak their own dialect, Gero told CBC'sQuirks & Quarks in an interview that airs Saturday.

"Their society really is divided based on culture," he said. "Animals that have different dialects behave differently. They feed on different things. They raise their babies differently."

Gero has been studying sperm whales in the Caribbean for his PhD thesis. He and his collaborators in Canada and Scotland have been trying todecode sperm whale language by recording the voices of pairs of animals talking to one another and noting differencesamong the sounds they make.

Female sperm whales spend all year in family groups in subtropical regions of the ocean, while males roam all over the world. When two whales encounter each other, they make patterns of clicks called codas.

Unique individual voices

Some codas are spoken by all whales, but each in a different way, so that they can be told apart from one another.

"They actually have one particular coda that seems to function in telling individual identity," Gero said.

Other codas are unique to particular cultural groups. For example, in the Caribbean, whales make a coda that consists of two slow clicks and then a faster triplet.

Gero noted that humans tend to co-operate with others from the same cultural group, and he suspects that sperm whales have developed different cultures and dialects to bond groups together because co-operation is so important to their survival.

Sperm whales are the deepest diving whales, routinely diving to 1,200 metres and occasionally as deep as two kilometres as they hunt.

"Mom always has to dive down for food and baby can't dive with her," Gero said.

Because of that, babysitters are crucial.

"It takes a village to raise a sperm whale baby."