Song of blue whale reveals a new ‘tribe’

New population of blue whales found after marine researchers stumbled upon unique song.

Each region’s blue whales have a unique style.

A new population of blue whales has been found in the Indian Ocean after marine researchers stumbled upon their unique song.

Blue whales are the largest creatures ever to have lived, with hearts the size of Volkswagen Beetles and stomachs that can hold at least a tonne of krill.

Little is known about how the species is faring but it now seems that this one population, which may include scores of individuals, had escaped detection. The group was found thanks to their low-pitched calls, which can travel underwater for just under 1000km.

Only the males sing but their drone is as loud as a large ship. It is unclear if this extraordinary communication, at the farthest reach of human hearing, is ­intended to repel rivals, attract a mate or achieve something else.

Conveniently for researchers, each region’s whales have a unique style. Its particular tune has been heard in the northernmost reaches of the Arabian Sea, as far south as the Chagos Islands and in the Mozambique Channel, west of Madagascar.

It has been added to the list of a dozen or so blue-whale songs.

Salvatore Cerchio, a marine mammal biologist at the African Aquatic Conservation Fund, was the first scientist to hear it.

His team was recording off Oman as part of research into the Arabian humpback whale when the scientists realised the music came from an unrecognised group of blue whales.

“It was remarkable to find a whale song in your data that was completely unique and to recognise it as a blue whale,” Dr Cerchio said.

The species has been studied for decades.

“With all that work on blue whale songs, to think there was a population no one knew about — it kind of blows your mind,” Dr Cerchio said.

His team notified the scientific committee of the International Whaling Commission. Their report was read by University of NSW researchers, who ­realised they’d heard the same song off the Chagos Islands.

It had previously been assumed the blue whales of the Arabian Sea belonged to a population off Sri Lanka, but the music told a different story.

“Before our recording off Oman, there was no acoustic data from the Arabian Sea, and so the identity of that population of blue whales was initially just a guess,” Andrew Willson, a member of the research team, said.

The Times