A Spa Day for Bowhead Whales

By Jacqueline Katz

In the summer of 2014, Ph. D. candidate at the University of British Columbia, Sarah Fortune, set out to study the feeding habits of Bowhead Whales and the role that climate change has played in their behaviors. But, her failure in this investigation spurred a new line of research.

Fortune had attached sticky tags on the whales’ backs to track their movement, and when the transmitter’s signal died on the second Bowhead she had tagged, Fortune thought nothing of it… until she noticed a group of whales “rolling onto their sides, lifting their flippers out of the water, doing headstands, lifting their tails out of the water” in the shallow, rocky waters of Cumberland Sound off the shore of Canada. And, she wasn’t the first; such observations were recorded by the Inuit and Whalers in the mid-1800s.

Upon closer investigation and with the help of drones, which provided an aerial view, Fortune determined that the whales had been molting. This shedding is not unheard of in whales – the beluga is known for the habit – but the behavior was never associated with Bowheads.  

It now makes sense why the Bowhead Whales migrate to the rocky bluffs off Baffin Island each year; scientists speculate that the warmer water boosts the metabolic activity in the whales, “speeding up the molting process and stimulating the growth of new hair and skin.”

Fortune hypothesizes that the Bowheads molt to remove the outer layer where harmful parasites, such as whale lice and diatoms, live or to rid themselves of unhealthy, sun-damaged skin. It is also a well-respected theory that the process may also help improve the whales’ hydrodynamic efficiency; removing the rough skin allows the Bowhead’s to move more rapidly and without as much effort.


Arnold, C. (2017, November 22). See What Happens at a 'Day Spa' for Whales. Retrieved November 27, 2017, from https://news.nationalgeographic.com/2017/11/whales-skin-spa-oceans-animals-science/#close

Quenqua, D. (2017, November 22). Even Whales Have to Exfoliate. Retrieved November 27, 2017, from https://www.nytimes.com/2017/11/22/science/whales-rocks-exfoliating.html?rref=collection%2Fsectioncollection%2Fscience