Researchers have captured drone footage of killer whales using kelp to groom one another — an extraordinary first in marine tool use.
In the remarkable footage, killer whales, also known as orcas, were seen grooming each other with strands of kelp, a type of seaweed. This marks the first known instance of marine animals using tools in a way previously believed to be exclusive to primates like humans.
According to a report by CNN, behavioral ecologist Michael Weiss from the Center for Whale Research in Washington state, was reviewing drone footage of orca pods in the Salish Sea in the inland waters of Washington state when he noticed something unusual. One of the killer whales appeared to be holding something green in its mouth, and several were rubbing against each other for as long as 15 minutes at a time.
“At first, I didn’t think much of it because whales do weird things,” Weiss tells CNN. But as he continued reviewing the footage, he noticed the same behavior happening again and again.
“I zoom in, and sure enough, there’s clear as day this piece of kelp that they’re using to rub on each other,” he adds.
Over the following two-week period in 2024, Weiss and his team captured 30 high-resolution examples of this curious behavior using drone footage. They observed southern resident orcas, a distinct population of killer whales, breaking off the short ends of bull kelp stalks. The whales would then press the kelp against a partner and roll it between their bodies for extended periods.
This behavior, which the researchers have dubbed “allokelping,” involves orcas rubbing kelp on one another, possibly to remove dead skin or parasites off each other’s bodies or as a form of social bonding. In a paper published in Current Biology on Monday, the researchers explain that the drone footage captured are the first-ever documented cases of mutual grooming in marine animals.
In the paper, the researchers also describe how the whales acquired kelp and used their teeth to shorten and shape the seaweed for grooming. This appears to be an example of tool use in killer whales, with the animals deliberately fashioning a tubular piece of kelp for a specific purpose.
Scientists have used drones for nearly a decade to study killer whales, and the aerial perspective has now helped uncover a previously unknown behavior in these marine mammals.
“What I find most remarkable is that despite this apparently being a common behavior [allokelping] — we see it most days we fly our drone over these whales—it hadn’t yet been discovered in this population despite nearly 50 years of dedicated observation,” Weiss says in a news release. “To me, this demonstrates not just the power of new observation methods but also how much we still have to learn about these animals.”
Image credits: All photos by Center for Whale Research, NMFS NOAA Permit 27038.
Source link