Play is an important part of animal behavior, helping different species form social structures and bonds, develop cognitive functions, and enhance physical fitness. However, humans don't know much about how other animals play. Now, scientists have discovered that baleen whales like to toss seaweed around, which may not just provide props for social playtime between whales, but provide a more specific service.
"Object use by cetaceans such as baleen whales is well known, and their ability to interact with their environment in complex behaviors has been reported before," said Olaf Meinecke of Griffin University's Center for Coastal and Marine Research. "But baleen whales, including humpback whales, are less frequently observed engaging in object use, and this behavior may be more common than previously thought."
The "kelping" behavior of whales (mainly humpback whales) has been observed off the coasts of Australia, the United States and Canada by lifting seaweed to their beaks. Drone footage also shows migrating whales searching for patches of seaweed and "playing" with them for up to an hour. Researchers believe that play may have other uses: For example, the rough and tough seaweed can be used to scrape dead skin cells, lice, barnacles and other parasites from the body, which can easily hitchhike on the body of large migratory mammals.
Scientists have previously documented whales wallowing in sandy bottoms, possibly as a way for them to shed dead epidermal cells and parasites during migration. Whales shed dead epidermal cells as they swim until they reach the waters near Antarctica. Here, their skin regeneration slows down and harmful bacteria have the potential to accumulate here. When they return to warmer waters, getting a beneficial scrub from some handy seaweed will be an effective way to speed up nature.
"There are two plausible theories: play and/or self-medication with seaweed," Meynecke said. "This behavior may be playful, but may also have additional benefits in terms of learning and socialization, as well as harnessing the antibacterial properties of brown algae to clear ectoparasites and treat skin."
The team analyzed more than 100 records of interactions with seaweed, involving 163 baleen whales. Humpback whales are the biggest "fans", participating a total of 95 times, followed by gray whales (2 times), southern right whales (2 times) and northern right whales (1 time).
Interestingly, adult whales came into contact with seaweed more than calves; of the interactions that could be identified, adults accounted for 53% and calves only 14%. This also provides some clues as to how this behavior serves another purpose. And this behavior is strikingly similar across species and geographical regions.
Seaweed is at the heart of a booming field of scientific research, with potential for use as fuel, new materials, sustainable methane-fighting feed and skin health.
It has to be said that compared to humans, whales seem to have already taken the lead in utilizing the skin care properties of algae.
The research was published in the Journal of Marine Science and Engineering.