Narwhal
Monodon monoceros
The unicorn of the sea — except the horn is a tooth, and it can feel.
Narwhals spend their whole lives in freezing Arctic water, diving under sheets of sea ice in the dark of polar winter. And sticking straight out of the male's face is a three-metre spiral tooth that nobody fully understood until recently.
On the conservation status
Currently stable, but narwhals depend completely on Arctic sea ice — which makes them one of the most climate-vulnerable whales on Earth.
- Length
- 4–5.5 m, not counting the tusk
- Weight
- 800–1,600 kg
- Lifespan
- Up to 50 years
- Diet
- Halibut, cod, squid, shrimp
- Tusk length
- Up to 3 m (10 ft)
- Dive depth
- 1,500 m under sea ice
The good stuff.
The tusk is a tooth turned inside out
It's the left canine, pushed straight through the upper lip, spiralling counter-clockwise. On a normal tooth the hard enamel is outside and the sensitive part is inside. A narwhal tusk is the opposite — soft and sensitive on the outside.
It's a sensor, not a sword
Around ten million nerve endings connect the tusk's surface to the brain. Narwhals can likely taste the water with it — sensing saltiness, temperature and possibly where the fish are.
They also use it to hunt
Drones have filmed narwhals tapping and stunning Arctic cod with quick flicks of the tusk before eating them. Before that footage existed, this was only a guess.
Mostly the males have one
About 15% of females grow a tusk too, and roughly one narwhal in 500 grows two. Males also cross tusks in a behaviour called tusking, which may be a way of comparing size without fighting.
No dorsal fin, on purpose
A tall fin would be a problem for an animal that spends winter swimming under solid ice. Narwhals have a low ridge instead — and so do belugas, for exactly the same reason.
They funded castles
Medieval traders sold narwhal tusks across Europe as genuine unicorn horns, at many times the price of gold. Queen Elizabeth I is said to have received one valued at the price of a castle.
Wait, really?
- ✦
Narwhals can hold their breath for around 25 minutes under solid ice.
- ✦
Their skin, called muktuk, is an important traditional Inuit food and is unusually rich in vitamin C.
- ✦
Monodon monoceros means one tooth, one horn.
What it sounds like
Whistles, pulsed calls and knocking click trains that bounce off the underside of the ice.
Where you might see one
Baffin Bay, Lancaster Sound in Canada, and the fjords of northwest Greenland. Almost nowhere else on Earth.
The trouble
- Sea ice loss
- Increased Arctic shipping noise
- Killer whales moving north into newly ice-free water
- Ice entrapment when leads freeze over
One real thing
Narwhals need a cold Arctic. Learn where your household energy comes from — that's the lever that actually matters here.
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