Scientists record 'lonely' bottlenose dolphin talking to himself in the ocean

A dolphin who scientists believe could be “lonely” has been recorded talking to himself in the Baltic Sea.

Dolphins are very social animals that scientists have observed “smiling” while playing with one another.

But a solitary bottlenose dolphin, known by the name Delle, has been observed near the Svendborgsund channel in Demark and scientists think he could be lonely.

Because the channel is not commonly occupied by bottlenose dolphins, experts went about researching how the presence of Delle may be affecting other inhabitants of the waters.

A recording device was used to pick up sounds. But, heartbreakingly, experts soon realised Delle appeared to be talking to himself.

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“Out of curiosity, I decided to add a recorder that captures actual sounds,” Olga Filatova, cetacean biologist at the University of Southern Denmark and lead author of the study, told Live Science.

“I thought we might pick up a few distant whistles or something along those lines,” she added. “I certainly didn’t anticipate recording thousands of different sounds.”

They picked up thousands of whistles, bursts of clicks and other sounds of varying frequencies. In total, 10,833 sounds were picked up over 69 days of recording.

The recording picked up three different distinct whistles, all of which were produced by Delle.

“Bottlenose dolphins have what are known as signature whistles, believed to be unique to each individual, much like a name,” Filatova explained.

“If we hadn't known that Delle was alone, we might have concluded that a group of at least three dolphins was engaged in various social interactions.”

She continued: “These sounds are traditionally considered communicative, meaning there should be at least two dolphins 'talking' to each other. But Delle was completely alone.”

Along with the loneliness theory, the researchers also reasoned he could be vocalising in the same way that humans might laugh out loud when reading something funny, even if no one else is around.

It comes after scientists found that dolphins “smile” during play. Researchers have found bottlenose dolphins (Tursiops truncates) have an “open mouth” expression that they use to communicate with each other during play, much like a smile in humans. Read more here.

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