Shell Prison: The Fascinating Dolphin Hunting Technique Captured on Film

Off the coast of Australia, scientists filmed a spectacular hunting technique in large dolphins, illustrating once again the intelligence of these creatures and their highly social nature.

The « shelling »

Documented in the waters of Queensland, in northeastern Australia, this behavior involves the use of a large shell that cetaceans use as a trap. Holding the object in their mouth, they pursue schools of fish, and once their prey is trapped, they surface and swallow it.

As the authors of the new study explain, published in the journal Marine Mammal Science, the first observations of this “shelling” came from Shark Bay, along the west coast of Australia, which suggests transmission within the same group, as well as to other geographically distinct groups.

“We watched a juvenile carefully observe its mother. Re-emerging at the surface with a shell and a fish trapped inside. When the latter escaped from its prison, she dropped this tool and continued her meal,” write the team. “A few minutes later, the juvenile seized the same shell in its mouth, and held it exactly in the same way as its mother.”

According to Alexis Levengood, from the University of the Sunshine Coast, this is probably the first evidence of maternal social transmission of a tool-using hunting behavior among dolphins. “Their use in non-human species helps illuminate our own evolution and its mechanisms,” the researcher says.

Unusual cases of cultural transmission observed in other species

Among the most intriguing cases of cultural transmission in animals, research conducted in Zambia last year revealed a novel craze among chimpanzees described as “fashionistas.” Persisting long after the instigator’s death, named Julie, it involved inserting blades of grass into their ears… and their hindquarters.

About forty years ago, groups of orcas roaming the northeast Pacific were observed wearing dead salmon on their heads as a headdress. If such behaviors have been reported again in recent years, the true reason behind them remains unknown.

Since 2020, these cetaceans have also been making headlines in Spanish waters. In six years, they have sunk no fewer than eight boats, usually by destroying their rudder.