By W. Scoresby. [Public domain], via Wikimedia Commons.

The Curious Case of the Narwhal’s Tusk

For centuries, the purpose of a narwhal's long, spiralling tusk has been a mystery. Now, with the help of some drones, we have an answer.


Narwhals may be one of the strangest creatures you’ll ever see. Like a beluga whale, but with a long, spiralling tusk protruding from their heads, it’s no wonder the narwhal is nicknamed the “unicorn of the sea”. For centuries scientists have been speculating about the purpose of these mysterious tusks.

Now, thanks to some drone-captured camera footage, we may have a clearer picture.

Scientists working with the Department of Fisheries and Oceans Canada have analyzed the video footage and determined that the narwhals appear to be using their tusks to club and stun fish before eating them.

Dental check-up

The narwhal’s tusk is actually an enlarged canine tooth that protrudes out of its mouth, most often on the left side and usually only in males. The tusk grows throughout the narwhal’s life and can reach over three metres in length!

People have been wondering about the purpose of the narwhal tusk since at least 1495, suggesting they serve as a digging tool, a tool to break up ice, a breathing organ, a self-defense weapon, or a symbol of prowess to impress females and establish hierarchy.

Three years ago, analysis of narwhal tooth composition revealed over 10,000 nerve endings, leading researchers to test its sensory ability. By capturing narwhals (don’t worry, the animals were released unharmed), putting plastic cones full of different water solutions over their tusks, and measuring heart rate, researchers found that the animals could indeed sense changes in salt content of water.

This ability is hypothesized to help the narwhals predict when ice is forming or melting – important to make sure they don’t get trapped beneath it. Yet these types of studies, although interesting and informative, can’t reveal how the animals behave in their natural habitat. That’s where the drones come in.

Narwhal surveillance

Drones are becoming increasingly useful in many applications including emergency healthcare and geography. In this case, they were let out to catch footage of narwhals swimming near the surface of Tremblay Sound – an area that they go to feed in during the summer.

Though short, the video shows a narwhal flicking its head as it approaches a fish, apparently stunning it before going in for a snack. The researchers claim this type of footage could never have been captured from shore or a boat.

The clubbing method also apparently varies depending on the number and type of fish the narwhals are hunting. Full details will hopefully be revealed in a research paper that is currently being prepared.

In the meantime, the narwhal will continue to be a strange and magical creature.

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Malgosia Pakulska is a freelance science writer, speaker, and blogger. She completed her PhD in Professor Molly Shoichet’s lab studying drug delivery systems for spinal cord regeneration after injury. She is still passionate about research and wants to share that excitement with the public. When she is not in the lab, she is experimenting in the kitchen and blogging about it at Smart Cookie Bakes.