Seals sing ‘otherworldly’ songs structured like nursery rhymes

When male leopard seals dive down into icy Antarctic waters, they sing songs structured like nursery rhymes in performances that may last as long as 13 hours, scientists mentioned Thursday.

The Australian-led staff of researchers in contrast the complexity of the songs composed by the large blubbery mammals to these of different animals — in addition to human musicians just like the Beatles and Mozart.

Lucinda Chambers, a bioacoustics PhD scholar at Australia’s University of New South Wales, instructed AFP that individuals are usually shocked after they hear the “otherworldly” hoots and trills sung by leopard seals.

“It kind of sounds like sound effects from an ’80s sci-fi” film, mentioned the lead writer of a brand new examine within the journal Scientific Reports.

During the spring breeding season, male leopard seals dive underwater and carry out their songs for 2 minutes earlier than returning to the floor for air. They then repeat this efficiency for as much as 13 hours a day, in accordance with the examine.

The researchers decided that each one leopard seals share the identical set of 5 “notes” that are unattainable to tell apart between people.

However every seal arranges these notes in a singular method to compose their very own private track.

“We theorise that they’re using that structure as a way to broadcast their individual identity, kind of like shouting their name out into the void,” Chambers mentioned.

The researchers consider the males use these songs to woo potential feminine mates — and push back rivals.

– ‘Songbirds of the ocean’ –

The staff studied recordings of 26 seals captured by examine co-author Tracey Rogers off the coast of Eastern Antarctica all through the Nineties.

“They’re like the songbirds of the Southern Ocean,” Rogers, who can be from the University of New South Wales, mentioned in an announcement.

“During the breeding season, if you drop a hydrophone into the water anywhere in the region, you’ll hear them singing.”

The staff analysed how random the seals’ sequences of notes had been, discovering that their songs had been much less predictable than the calls of humpback whales or the whistles of dolphins.

But they had been nonetheless extra predictable than the extra complicated music of the Beatles or Mozart.

“They fall into the ballpark of human nursery rhymes,” Chambers mentioned.

This made sense, as a result of the songs have to be easy sufficient so that every seal can keep in mind their composition to carry out it day-after-day, she defined.

She in contrast it to how “nursery rhymes have to be predictable enough that a child can memorise them”.

But every seal track additionally must be unpredictable sufficient to face out from these of the opposite males.

Leopard seals, that are the apex predator in Antarctic waters, swim alone and canopy huge distances. They doubtless advanced their explicit sort of track in order that their message travels lengthy distances, the researchers theorised.

Varying pitch or frequency may not journey as far of their surroundings, Chambers mentioned.

Female seals additionally sing typically, although the scientists have no idea why.

Chambers prompt it might be to show their pups the way to sing — precisely how this expertise is handed down can be a thriller. But she added that this behaviour has by no means been noticed within the wild.

The females might additionally simply be speaking with one another, she mentioned.

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