Photo: Whale Watch Western Australia
There is so much that we do not understand about the social behaviors of whales and dolphins. Dolphins off the Australian coast, for example, have been observed wearing sponges as hats in what is believed to be an attempt, though not often necessarily successful, to attract a mate. Likewise, in 1987 off the coast of Washington, at least three groups of teenaged orcas inexplicably began wearing dead salmon as hats. The behavior spread in what appeared to be a “fad” for a few months before disappearing again.
Humpbacks and other baleen whales have been observed “kelping”, balancing seaweed on their rostrum — their flat upper head. In a recent study from Griffith University in Australia, researchers have observed that this behavior is far more common than previously appreciated. Also, while the activity appears playful, it may have other benefits for the whales.
The researchers collected over 100 examples on social media of whales playing with seaweed, known as “kelping”. They note that it’s not just one species – gray whales, southern and northern right whales, and humpback whales all do it.
They observed that, to date, there are far more social media and news reports on whale play with seaweed than scientific literature. A 2011 study in New South Wales described these interactions as playful behavior. Other researchers have documented instances of whales moving logs through the water in Colombia or interacting with jellyfish on the United States East Coast.
From their new research, they deduced two things. First, the behavior is playful. And second, it’s likely to have a useful component, such as using the seaweed to scratch an itch (hard without hands), brush off baby barnacles, or flick away whale lice – parasites that drive the whales mad.
In short, kelping might be more than just play. Toying with seaweed might have benefits other than just being fun. Some of us enjoy seaweed wraps at a spa or as a facial mask.
It might be the same for whales. Some seaweed species have been found to reduce bacterial growth, which could be useful for whales, as their skin hosts a range of viruses and bacteria. Whales have to constantly shed their skin to keep on top of bacterial growth.
There are other possibilities. Pushing through seaweed again and again could also help whales rid themselves of unwanted guests, such as the early life stages of barnacles and sea lice. Because whales are so large, many species of invertebrates hitch a lift or spend their lives on these creatures – and often to the whale’s annoyance. Grey whales off the coast of Mexico have repeatedly approached humans for help in keeping down numbers of itchy whale lice, which are actually more closely related to a shrimp or small crab than to lice.
Here is a short video of a humpback kelping captured by Mark Girardeau while aboard Newport Coastal Adventure.
Thanks to Dick Kooyman for contributing to this post.