Orcas Use Kelp Tools Cooperatively for Grooming

Southern resident killer whales have been observed using bull kelp cooperatively for grooming in a behavior termed 'allokelping,' the first documented case of tool-making and cooperative tool use in marine mammals. Researchers used drone footage to witness orcas deliberately detaching and shaping kelp, then rolling it between each other's bodies, likely promoting skin health and reinforcing social bonds. This behavior differs from previously known solo 'kelping' and was seen across all ages and pods, indicating it is widespread in the critically endangered population. The practice appears to serve hygienic and cultural functions, with evidence suggesting it may be most common among closely related individuals. The discovery highlights orcas' advanced intelligence and social complexity, paralleling grooming behaviors in primates. It also shows the importance of drone technology in revealing otherwise hidden animal behaviors.