Tomorrow is April Fool’s Day! And what better way to celebrate than with an animal that I always forget exists: the narwhal.
In my defense, narwhals look fake. What other animal has a giant tusk coming out of its head? I mean, besides a unicorn, and I’m pretty sure unicorns aren’t real.
Narwhals are known, though, as ‘unicorns of the sea.’ In fact, Medieval Europeans thought that narwhal tusks were unicorn horns. Hunters would sell narwhal tusks for large amounts of money to European rulers, wealthy citizens, and even the church.
But I’m here to tell you: even if unicorns aren’t real, narwhals most certainly are.
What is a narwhal?
Narwhals (Monodon monoceros) are large, carnivorous porpoises with a prominent tusk. They are cetaceans, the same family that includes dolphins and whales. Their scientific name means “one tooth, one horn” (more on their horn in a second).
[A quick note on porpoises vs. dolphins: while both are marine mammals, they don’t look similar. Dolphins are more streamlined, with longer noses, more curved dorsal fins, and leaner bodies than porpoises.]
If you wanted to color a picture of a narwhal, you’d first need to know its age since its color changes based on age. They go from blue-gray as newborns to blue-black as juveniles. Adults are a mottled gray that shifts to nearly all white with age.
This coloration is actually where we get the name ‘narwhal.’ In old Norse, ‘nar’ means ‘corpse,’ and ‘hval’ means whale. So, narwhals are ‘corpse whales,’ with skin the color of a drowned sailor.
Why haven’t I seen a narwhal?
There are a few reasons. First, narwhals don’t do well in captivity. People tried to catch and keep them in zoos and aquariums in the 1960s and 1970s, but all captive narwhals quickly died.
And if you want to try to see a narwhal in nature, you’ll have to travel to the Arctic. Narwhals are found almost exclusively in the Arctic, with their range reaching the polar ice cap. During the winter, narwhals will even spend entire months under the sea ice – they survive by breathing through tiny cracks in the ice. You might be able to see them during the summer when they migrate to slightly warmer waters. However, you’ll still have to travel to the fjords and coastlands of Greenland and Canada for the chance of a glimpse.
What’s with the tusks?
A narwhal’s tusk is actually a tooth. In fact, it’s one of just two teeth that narwhals have.
In males, this tooth grows into a counterclockwise spiraling tusk that juts straight through their upper lip. And not a puny-sized tusk, either: this spiral tusk can grow up to 10 feet long in males. Females also sometimes grow a tusk (around 3%), but it remains much smaller.
Like human teeth, this tusk isn’t just bone – it contains blood vessels, sensory tissue, and nerves. But unlike human teeth, this material is on the outside of the tusk. This means that narwhal tusks could help sense things in the surrounding ocean, like ice formations and saltiness.
Why do narwhals have tusks? They may be used in mating rituals to impress potential female mates or battle rival males. The tusk could also be used to establish dominance within narwhal groups. Support for this idea comes from the fact that males are the ones who usually have a tusk.
How do they eat with only a tusk and a tooth?
Great question. Obviously, with only two teeth (one of which is a tusk in males), it would be difficult for narwhals to chomp on their food!
So instead of biting, narwhals create a vacuum with their mouths to suck up their prey. This mouth vacuum lets narwhals suck up fish and crabs living on the seafloor. And since it’s pretty hard to chew with just one tooth, narwhals usually eat their food whole.
What else do narwhals do?
While their tusk is striking, narwhals act and behave very similarly to other species of porpoises, dolphins, and whales.
For example, they live in groups of 10 to 20 individuals that travel together and hunt via echolocation.
Narwhals can also spend a lot of time underwater. As one of the deepest diving whales, they can hold their breaths for up to 25 minutes! They also have high concentrations of myoglobin in their muscle tissue, which helps them use oxygen effectively.
One last fact: to deal with the cold Arctic waters where they live, narwhals are about 40% blubber!
Is anyone down for an Arctic cruise?