The unicorn of the sea: Ten facts about narwhals

The narwhal has brought wonder, curiosity and speculation for centuries. Unlike some whale species that migrate, narwhals spend their lives in the Arctic waters of Canada, Greenland, Norway and Russia. Here’s ten facts you may not have known about this remarkable Arctic species:

1. Naming

Narwhal or Monodon monceros in Greek means “one-tooth-one-horn.” In Inuktitut, narwhal is Qilalugaq gernertaq which translates to “the one point to the sky.” I think I know why…

Narwhal crossing tusks above water surface. Baffin Island, Nunavut, Canada. © / Eric Baccega / WWF

2. Closest relatives

The Narwhal is most closely related to the beluga. Like the beluga it evolved without a dorsal fin, allowing the narwhal to break thin sea-ice if necessary in order to breathe.

3. A tusk or a tooth?

The Narwhal tusk is a modified tooth in the upper left side of the jaw. Male narwhals commonly have a single tusk though a few may also have two tusks.  Up to 2 per cent of females have an erupted tusk.

Close up of Narwhal (Monodon monoceros) in water showing its spiralled tusk, Northwest Greenland. © / Bryan and Cherry Alexander / WWF

4. Eating

Narwhals have no actual teeth protruding inside their mouth, but that’s okay because they are suction feeders swallowing their prey whole.

5. Diet

Narwhals feed mainly on Greenland halibut, Arctic and polar cod, squid and shrimp. It appears that narwhals find their winter food supplies down towards the seafloor (down to 1 mile depths even!) and in the spring, find their food near the ice edge.

Aerial photo of Narwhals  in Arctic Canada. © Janet FOSTER / WWF-Canada
Aerial photo of Narwhals in Arctic Canada. © Janet FOSTER / WWF-Canada

6. Sensory capabilities

The tusk isn’t just an elongated highly modified tooth, but a complex sensory organ. Research has shown that the narwhal tusk has some remarkable sensory capabilities, with up to 10 million nerve endings inside, perhaps to help in detecting small changes in water quality, and in locating food.

7. Changing colours

Narwhals change colour with age. Newborns are mottled blue-grey, juveniles are completely blue-black, adults are spotted grey and old narwhals are nearly all white.

Female narwhal (Monodon monoceros) Canadian Arctic. © / Doug Allan / WWF

8. Great divers

Narwhals commonly dive to 500 metres, though they can dive in excess of 1,500 metres for more than a 25 minute period.

Aerial view of Narwhal (Monodon monoceros) group migrating, Lancaster Sound, Canadian Arctic, © / Doug Allan / WWF

9. They are pretty big

They can weigh up to 1.5 tonnes and adult males can be about five metres long.

10. Affected by climate change

Like polar bears, narwhals depend on sea ice and are directly impacted by rapid climate change –studies have shown that they are one of the species most vulnerable to the ecological effects of climate change because of increased predation by killer whales, changes to their prey base, and likely increased risks of entrapment in unpredictable ice conditions.
As summer home to over 80,000 narwhals (about three-quarters of the world’s total population), Canada is in a unique position to keep narwhal populations healthy by ensuring that their habitat remains intact and not significantly impacted by human activities.
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