Dolphins Are Learning A Strange New Hunting Technique Using Shells And Seem To Be Teaching It To Others: Watch The First-Ever Footage

The behavior was caught on camera (footage below) near the Great Sandy Marine Park off Hervey Bay in Queensland, northeastern Australia. 

What is shelling?

It goes a little something like this: the bottlenose dolphin will first chase fish into a large empty shell. Then, they bring it to the water's surface in their mouth, shake it around, and slurp up the trapped prey.

Known as shelling, it had previously been documented in a group of dolphins in Shark Bay on the other side of Australia, along the west coast.

So, when another team of scientists saw it on the east coast of Australia, they knew exactly what they were looking at. 

“We were on a research boat off Hervey Bay when we spotted a dolphin raising something large out of the water. I started screaming because I know what shelling looks like,” Dr Alexis Levengood, the study’s lead author and marine mammal expert at the University of the Sunshine Coast, said in a statement. 

“We were able to record footage and take photographs of dolphins shelling in the Great Sandy Marine Park, which is the first published record of it on the east coast of Australia,” she added.

Big implications for dolphin brains

These shenanigans raise some big questions about animal behavior. In their new study, the researchers explain that it’s possible that shelling emerged in both populations through independent innovation. Perhaps by trial and error, both groups coincidentally stumbled across the same method for hunting fish. It worked well, so it stuck. 

However, it’s also plausible that shelling was taught to other dolphins through social transmission. Affirming this idea, the team saw one calf closely watching its mother as it was shelling.  

“We saw the mother surface with a shell, the fish inside escaped, and the dolphin dropped the shell to chase the fish. Then, minutes afterwards, the dolphin calf picked up the shell and held it the same way as its mother,” explained Dr Levengood.

“Our footage provides the first potential evidence of maternal social transmission – a process by which offspring learn behaviour by observing the actions of its mother. It challenges the belief that dolphins learn this tool use from their peers,” she continued. 

“These findings highlight how smart, clever, and innovative dolphins are.”

Animals are very cultured beings

This type of cultural transmission is seen in a bunch of animals. Research in Zambia showed that chimpanzees would copy “seemingly pointless behaviors” from one another, just like humans do with fashion trends and fads. 

One of the strangest appeared to be a female chimpanzee named Julie who was regularly seen poking grass into her ear and leaving it there. The behavior did not appear to serve any practical function, but it was later adopted by seven other chimps in the same group and persisted even after Julie’s death.

There was also that strange episode when numerous orcas in the northeast Pacific started wearing dead salmon as hats – yeah, no clue.

It's no secret that dolphins are incredibly smart creatures, so the theory that shelling was passed on through cultural transmission isn't far-fetched at all. Still, the researchers are keen to follow up with more studies before drawing any bold conclusions.

“There’s still a lot we don’t know and many questions we will hopefully ask and answer with time. But better understanding shelling, and other tool use in non-human animals, will continue to teach us more about ourselves and how and why we evolved the way we did,” Dr Levengood concluded.  

The study is published in the journal Marine Mammal Science.