Lonely dolphin has highly vocal conversations with himself, surprised researchers say

He’s really blubbering.A dolphin living in isolation in the Baltic Sea seems to be talking to himself, according to new research in the journal “Bioacoustics.” The marine mammal, nicknamed Delle by locals near the island of Funen in Denmark, has been sighted in solitary confinement around the area since 2019.Researchers began to use underwater recording devices on Delle, a bottlenose dolphin who lives out of the social species’ typical range, to see how his solo presence affected porpoises near the harbor.However, contrary to the notion that Delle would be quiet under the circumstances, “we found the dolphin to be highly vocal,” according to the paper.“I thought we might pick up a few distant whistles or something along those lines,” biologist and University of Southern Denmark researcher Olga Filatova told Live Science.“I certainly didn’t anticipate recording thousands of different sounds.” Just over three months, from December 2022 to February 2023, 10,833 different sounds were detected.

Several noises — like whistles, clicking and burst pulsing — are associated with communication.“Bottlenose dolphins have what are known as signature whistles, believed to be unique to each individual, much like a name,” Filatova said.

“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.”The team even thought Delle was trying to speak with a local paddleboarder, but that was ruled out — as was the idea he was sending an SOS to any potential pods in the region.Filatova likened Delle’s cries potentially to that of “much like how we sometimes laugh when we read something funny, even if no one else is around to hear.”...