A dolphin who had lived alone for years off the coast of Denmark was wiretapped. The recorded “conversation” is unprecedented

News JVTech A dolphin who had lived alone for years off the coast of Denmark was wiretapped. The recorded “conversation” is unprecedented

A dolphin not so alone

Previously unpublished sound recordings, made over several months, reveal astonishing vocal behavior and raise fundamental questions about solitude, adaptation and animal communication. Delle, aged 17, was spotted five years ago in the Svendborgsund canal, an unusual environment for his species. What immediately intrigued scientists was its total isolation. Nariz de botella dolphins are indeed extremely social animals, usually living in complex groups. The absence of conspecifics around Delle presented a puzzle and a unique opportunity for researchers at the University of Southern Denmark.

Between December 2022 and February 2023, they equipped Delle with a hydrophone

an underwater microphone, in order to record its sound emissions. The result exceeded all expectations: more than 10,800 distinct sounds were captured, including whistles, low tones, percussive sounds and series of rapid pulses. The latter are generally associated with aggressive behavior within groups of dolphins. However, Delle being alone, the interpretation of these sounds took on a whole new dimension.

The most surprising hypothesis put forward by the researchers is that of a form of “self-conversation”. This behavior, although documented in humans, particularly in situations of prolonged isolation, has never been observed in dolphins. Could Delle have developed this strategy to compensate for the lack of social interactions? Scientists remain cautious, but this avenue opens fascinating perspectives on the capacity for adaptation and cognitive complexity of these marine mammals.

Schizophrenic loneliness

Another element intrigues researchers: Delle uses three “signature whistles”, a sort of individual name allowing dolphins to recognize each other. However, each dolphin generally only has one. Creating these extra whistles could be another manifestation of its need to communicate, even in the absence of receptors. As if he were speaking to imaginary interlocutors, thus populating his sonic solitude.

Several hypotheses have been considered to explain Delle’s isolation. Was he rejected by his group? Did it get lost and drift away from its natural habitat? The reasons remain obscure, fueling the mystery around this solitary dolphin. What is certain is that Delle was able to adapt to this extreme situation, developing unique vocal behaviors.

The dolphin is finally close to humans

Delle’s case study highlights the complexity of social life in animals and the coping mechanisms implemented in the face of isolation. It also highlights the importance of communication for these highly social creatures. While we cannot say with certainty that Delle “talks” with himself in the human sense of the term, his sound emissions demonstrate a rich cognitive activity and a remarkable adaptation to a socially deprived environment.

Delle’s story reminds us how much remains to be discovered about the lives and behaviors of marine animals. It calls for greater humility in the face of the richness and complexity of the animal world, and underlines the importance of continuing research to better understand and protect these fragile ecosystems. Beyond the anecdote, Delle becomes a symbol of the resilience of life and a formidable subject of study for scientists. His underwater “monologue”, far from being simple background noise, could well reveal to us unsuspected secrets about the intelligence and adaptability of dolphins. Maybe even teach us something about ourselves and our own relationship with solitude. One thing is certain, Delle will continue to intrigue and inspire researchers for a long time to come. And each new recorded sound will be an additional piece of the puzzle of his mysterious and lonely life.