In a remarkable discovery, researchers have observed killer whales (Orcinus orca ater) in the Salish Sea engaging in what appears to be tool-making behavior, a first for marine mammals. These whales have been seen biting off short stalks of bull kelp (Nereocystis luetkeana) and using the pieces to groom one another. Published in Current Biology, this behavior may represent not only the first recorded instance of tool use among marine mammals but also a form of social interaction that benefits two individuals simultaneously. Michael Weiss, a behavioral ecologist at the Center for Whale Research in Friday Harbor, Washington, remarked on the initial surprise of witnessing this behavior through drone footage, which became more frequent upon focused observation.
The grooming behavior was initially considered an anomaly; however, the research team later recognized it as a regular occurrence. They recorded high-resolution footage during the spring and summer of 2024, revealing that the whales press the kelp against each other and roll it between their bodies. The method of tool use involves biting the kelp and shifting their heads, taking advantage of the buoyancy and structure of the kelp—its large bulb and fronds assist in breaking off stalks. Such a practice highlights the whales’ intelligence and adaptive strategies for maintaining their health and social bonds.
The observational study found that partnerships tend to form between closely related or similarly aged whales, suggesting that the grooming not only serves a harborage for hygiene—potentially helping to remove dead skin—but also reinforces social connections. Interestingly, whales exhibiting more dead skin had greater participation in these grooming sessions, hinting at the practical benefits of their kelp tools. The team’s research aims to continue over several years to ascertain the primary function of the kelp tool use and its implications for social bonding within whale pods.
While other marine mammals, like dolphins, utilize tools such as sea sponges and coral for grooming or foraging, the killer whales’ behavior stands out as a unique display of crafting tools in a marine environment. If confirmed, this behavior provides a significant insight into the cognitive capabilities of these cetaceans. The team acknowledges that, while killer whales may be some of the most extensively studied marine mammals, much about their behaviors remains unexplored, indicating a wealth of knowledge yet to be uncovered.
The broader implications of this behavior could influence our understanding of marine mammals’ social structures and their interactions with their environments. The ongoing research could reveal crucial aspects of the whales’ lives, encompassing everything from their grooming practices to how these behaviors contribute to their social dynamics and overall well-being. As the study unfolds, we can anticipate a deeper understanding of both the species and the ecological roles they play in the Salish Sea.
Erin I. Garcia de Jesus, a staff writer for Science News, emphasizes the importance of science journalism in disseminating critical findings to the public. By supporting platforms that enhance scientific literacy, we can foster a culture of informed decision-making that integrates scientific knowledge into societal issues. As research into these killer whale behaviors continues, the connection between science communication and public engagement becomes ever more significant.
