Researchers studying a wild solitary dolphin named Kylie found that she might very well be speaking porpoise. Photo: Unsplash
Dolphins are intelligent creatures. They can solve complex problems. They enjoy social interaction. They play for the sake of playing. There’s a lot of evidence that could prove they have their own language, and although that last part’s not a sure-thing, it’s entirely clear that dolphins ain’t dumb. And recently, a wild dolphin has been observed doing what looks a lot like “talking” with harbor porpoises.
Swimming around in the cold waters off the west coast of Scotland is a dolphin named Kylie. She’s been thought of as a somewhat solitary creature — she hasn’t been observed with other dolphins in 14 years — but as it turns out, she’s been palling around with harbor porpoises.
According new research published in Bioacoustics and reported on by National Geographic, Kylie doesn’t make the normal sounds we often think of as dolphin noises – the whistles and pulse calls. Instead, she sounds a lot more like a harbor porpoise, using high-pitched bursts of clicks to communicate.
“The study suggests that she may be communicating with the porpoises, or at least attempting to,” wrote Elizebeth Ann Brown. “It’s part of a growing body of work that illuminates a rich world of interactions between different cetacean species.”
While it’s not known how much, exactly, different animals engage vocally with each other in the wild, researchers are taking Kylie’s example as proof that they can and do.
“Clearly,” said dolphin behavior expert Denise Herzing, “species in the wild interact much more than we thought.”
Kylie’s home waters, the Firth of Clyde, is a large saltwater inlet that’s home to thousands of harbor porpoises. Years ago, residents in the area noticed that Kylie liked to spend time around a buoy near a loch called Kyles of Bute, which is where her name came from. Nobody, however, knows where she came from or why she might have ended up outside the company of other dolphins.
It’s been documented in the past that dolphins can be separated from their pods by things like storms, human activity, or being orphaned, but researchers also believe that some solitary dolphins just prefer to be left alone.
The founder of a Scottish organization called Clyde Porpoise that is devoted to the protection of marine mammals in the area spent a few years learning about Kylie’s unique relationship with the porpoises. David Nairn used a hydrophone attached to the back of a sailboat to record her calls between 2016 and 2018. “She definitely identifies as a porpoise,” he said.
Most porpoises, unlike dolphins, don’t actually whistle too often. They’re more partial to using different clicking sounds, almost exclusively with “narrow-band, high-frequency (NBHF) clicks,” with eight to 15 amplitude peaks at around 130 kilohertz.
Due to their high-frequency, these clicks are difficult for us to hear. “To hear an NBHF click,” Mel Cosentino, Ph.D. candidate at the University of Strathclyde in Glasgow told Nat Geo, “you have to play it about one hundred times slower.”
After listening to recordings from Kylie, Costentino found that she was using more clicks at a porpoise frequency than a normal dolphin. Interestingly, she did this even when no other dolphins or porpoises were in the area. Kylie, according to the researchers, never whistles, which is almost unheard of in dolphin populations.
In the course of Cosentino’s research, they noticed that when Kylie was around porpoises, the exchanges of clicks mimicked a conversation. Kylie would click, then pause and let the porpoises click back. Then she would do something that could be interpreted as a response. Rarely would the different species interrupt each other, although the researchers are quick to point out that they don’t know for certain whether what they’re hearing constitutes an actual exchange of ideas.
“It might be me barking to my dog and him barking back,” Cosentino said.
Still, though, even if a dog is only barking because it’s being barked at, that’s a close thing to a conversation — and the fact that Kylie is making porpoise sounds is an astounding bit of information from the natural world that might just mean that dolphins are able to learn a different language. And if they can do that, it could mean that we might be able to communicate with them at some point in the future, too.
