Bowhead Whales Rub their Backs on Rocks to Molt and Exfoliate their Skin (Study)

Researchers noticed an interesting behavior among a species of whales, which makes them swim a long distance just to scratch their backs. Bowhead whales migrate every summer to the waters of the Canadian Arctic just to rub on rocks. This process helps them exfoliate and get rid of old skin.

Bowhead whales exfoliate their skin by rubbing it on the rocks

Just like reptiles, the majority of whales and dolphins shed their skin and replace it with a new one. However, they cannot do it on their own, so they need a little help to remove that old skin. Therefore, they choose the same spot each summer, where they can rub against some rocks, exfoliate the skin on their backs, and remove all the parasites and dead cells.

Researchers didn’t quite understand this process in Arctic species. Narwhals and beluga whales, for instance, choose warmer regions to live during summer, and this helps them change the texture of their skin. However, a lot less was known about bowhead whales. Therefore, they decided to take a look at a population migrating in Nunavut during summer.

Molting helps them get rid of parasites and of old skin

Therefore, they took still photos of 81 bowhead whales, and recorded four of them. This is how they observed these shed their skin as well, as 40 percent of the specimens still carried molting skin on most of their body surface. Also, the videos captured them rubbing against rocks on the coast. This behavior was quite common among bowhead whales during summertime.

This is how they discovered why these whales return to this area in the warmer season. Rubbing helps them exfoliate their skin, facilitating the molting process. This way, they get rid both of the parasites which might have gathered on their backs, and of the dead and sunburnt skin. All the other details on the behavior of the bowhead whales has been published in the journal PLOS One.
Image Source: Wikimedia Commons