This Solitary Dolphin in the Baltic Sea Is Really Going Through It Right Now

A dolphin dubbed Delle appears to be talking to himself in the Baltic Sea’s Svendborgsund channel off the coast of Denmark. According to a team of researchers that recorded Delle, the solitary dolphin may be so desperate for social connection that he’s thinking out loud.

The researchers aren’t entirely sure why the animal produced “sounds typically considered communicative,” as they note in research published last month in Bioacoustics. But that makes Delle’s situation all the more compelling. Dolphins are very social animals, and chatter in a diverse array of clicks, squeaks, and other sounds. In lieu of other dolphins, Delle resorted to what the researchers call “self-talk.”

Delle was first spotted in the Baltic channel five years ago, and was noticeable because he was the sole dolphin in the area and didn’t belong to a pod. The researchers lowered a microphone into the water and recorded Delle’s sounds from December 2022 to February 2023—a total of 10,833 voicings. The noises included clicks, whistles, and bursts of sound often linked to aggressive interactions among dolphins.

“These sounds may be emitted unintentionally as emotional signals, serve functions other than direct communication, or simply be a byproduct of dolphins’ intrinsic need for social interaction,” the team wrote in the paper.

Bottlenose dolphins are very smart animals, continually surprising researchers with their skills. Last year, scientists discovered that the mammals can sense electricity, and may use that sense to find hidden prey or navigate using Earth’s magnetic field. The nature of Delle’s sounds was not clear but there are a handful of examples of other solitary dolphins and even whales making sounds without any companions of the same species to hear them.

Though those sounds are sometimes made to reconnect with other individuals, the research team doesn’t think it was the case with Delle; the animal had already been in the channel for about three years when it was recorded, more than enough time to determine that there were not other dolphins in the area.

Lonely dolphins can be more hazardous than Delle, who appears to simply be keeping himself entertained. In August, the Japanese Coast Guard had to put out a warning after several beachgoers were bit by a dolphin in Fukui Prefecture; experts suggested the animal was nipping to get attention, adding that if it wanted to cause harm, the bites would have been much more serious.

Loneliness in humans can result in similar behavior—talking to oneself and lashing out at others—but the research team stressed that “we should be particularly cautious in drawing conclusions about other species with complex communicative systems.”

Delle could be a rare example of how dolphins deal with loneliness, though the exact nature of the animal’s clicks and brays remains unclear. Maybe Delle is laughing, maybe he’s screaming. Maybe he’s just distracting himself from the intractable sorrow of solitude. Either which way, he’s a dolphin talking to himself.