When you are alone, especially for long periods of time, do you talk to yourself? If so, you’re in interesting company because a male Atlantic bottlenose dolphin who has been living alone in the Baltic Sea for more than three years, appears to be talking to himself.

Affectionately named Delle, a male bottlenose dolphin, has become an unexpected resident of the Baltic Sea, far from his species’ usual warm and bustling habitats. His unusual presence near Denmark’s Svendborgsund channel has intrigued marine biologists and captivated local communities,

What happens when a highly social creature like a bottlenose dolphin is left utterly alone? Delle, a solitary dolphin in Denmark, may be showing us.

The only dolphin in the Baltic Sea seems to like muttering to himself. Researchers are trying to figure out why.

Marine biologists are perplexed by the lone bottlenose dolphin's vocalizations, because some resemble sounds typically used for communication