Behavior in orca population off coast of US and Canada captured by scientists using drone observation
Killer whales have been observed mutually grooming each other with a type of seaweed, the first known instance of a marine animal using tools in a way that was previously thought to be the preserve of primates such as humans.
A group of killer whales, which are also known as orcas, have been biting off short sections of bull kelp and then rolling these stems between their bodies, possibly to remove dead skin or parasites. The behavior is the first such documented mutual grooming in marine animals and is outlined in a new scientific paper.
The discovery was made in a contained group of 73 killer whales that live in the southern part of the Salish Sea, a section of the Pacific Ocean hugging the coast of Washington state in the US and Canada’s British Columbia.
Researchers were surprised to see a whale remove a 2ft section of bull kelp, balance it on its nose and then approach another whale to wedge the kelp between their bodies and rub it between them. At first, the scientists thought this was a quirky one-off but then noticed this was a widespread behavior within the group, according to the paper, published in journal Current Biology.
