Orcas scrub each other clean with bits of kelp

Orcas off the west coast of North America have been observed engaging in a fascinating behavior – grooming each other with kelp, showcasing a rare instance of marine mammals using tools. This behavior was captured by scientists studying 80 endangered killer whales in the Pacific Ocean region between British Columbia and Washington state, utilizing drones for a comprehensive view of the whales’ activities.

Analysis of footage from the summer of 2024 revealed the orcas manipulating strands of kelp in a peculiar manner. The whales were seen breaking off kelp stalks near the rock bed, grabbing them with their teeth and moving their heads back and forth. They then proceeded to use these kelp segments to groom each other, rubbing and rolling them onto each other’s bodies in a coordinated fashion.

According to Rachel John from the Center for Whale Research in Washington state, this behavior is intriguing as it showcases the whales’ ability to use tools without having hand-like appendages. The orcas seemed to target specific segments of the kelp for grooming, indicating a deliberate and purposeful action.

This unique behavior, termed “kelping”, could be a social activity for the orcas to strengthen their bonds. The whales, irrespective of age or sex, participated in this grooming ritual, with closer relatives and similar-aged individuals showing a higher propensity to engage in kelp grooming. Additionally, the researchers found that orcas were more likely to clean each other with kelp when shedding skin, suggesting a possible hygiene aspect to this behavior.

Olaf Meynecke from Griffith University in Australia highlighted the potential health benefits of kelp grooming for the orcas, particularly in reducing skin infections. Further research to analyze the correlation between the whales’ skin bacteria and the properties of kelp could provide valuable insights into the advantages of this behavior.

Overall, the observation of orcas using kelp for grooming highlights the complex social dynamics and adaptive behaviors of these marine mammals. It opens up avenues for future studies on the health benefits and evolutionary significance of such interactions within whale populations.