It's a first: orcas caught creating tools to...massage themselves

In a recent study published in Current Biology, scientists from the University of Exeter and the Center for Whale Research shed light on a rather surprising behavior observed in killer whales.

For the first time, killer whales from the same population and across all age groups have been observed making massage tools using stems of giant brown seaweed in the Salish Sea, Washington.

These are not hunting tools, as is often seen among cetaceans, but rather a completely different system fashioned from seaweed to massage each other: in pairs, the killer whales roll these tools over their bodies for a certain period of time. This is a unique discovery in a population of marine mammals that has been studied for 50 years.

To alleviate stress

As Michael Weiss, CWR Research Director, explains, orcas do more than just "find a piece of seaweed" and "use it," they "modify it to make something truly different." He adds, "That's why we say they make or shape a tool." A practice that, according to researchers, helps reduce stress, strengthen social bonds, and also preserve the health of the orcas' skin.

And according to Darren Croft, a professor at the University of Exeter, this technique is "very rare" among cetaceans, which are limited to using specific tools solely for food. He points out that, for orcas, "it could be a health issue or […] related to the skin, but it seems very likely that it's related to a social challenge, a need for intense and meaningful social interactions."

A threatened population

The scientists behind the study explain that this may be a "unique" cultural trait specific to this population of orcas, the so-called "Southern Residents," which numbered only 73 by 2024. A population whose future remains "very bleak" due to the various threats facing them: marine pollution, disappearing prey, and declining brown algae due to climate change.

(MH with Raphaël Liset - Source : 20 Minutes - Illustration : ©Unsplash)