Narwhal

Introduction

The narwhal is one of the most unusual and mysterious whales in the ocean. It belongs to the same family as the beluga whale, and the two species are each other’s closest relatives. Narwhals are medium-sized toothed whales that spend their entire lives in the frigid waters of the Arctic. They are sometimes called the “unicorn of the sea” because of the long, spiral tusk that juts forward from the heads of most males. Scientists are still learning new things about narwhals because they live in such remote, icy places that are difficult for researchers to reach.

The Tusk

The narwhal’s famous tusk is not actually a horn at all — it is a tooth. Specifically, it is the left upper canine tooth, which grows outward through the lip in a counter-clockwise spiral that can reach lengths of up to three meters (about ten feet). Almost all male narwhals grow a tusk, but females rarely do, and on very rare occasions a male will grow two tusks. What makes the tusk so unusual is that it contains up to ten million tiny nerve endings, which allow the narwhal to sense changes in water temperature, pressure, and salt levels. Scientists believe the tusk works as a sensory organ, helping narwhals gather information about the ocean around them. Males have also been observed crossing their tusks above the surface in a behavior called “tusking,” which may be a way of communicating or establishing dominance.

What They Look Like

Narwhals are stocky, muscular whales that grow to about four to five and a half meters long (13 to 18 feet), not counting the tusk. Adults weigh between 800 and 1,600 kilograms (roughly 1,800 to 3,500 pounds), with males being larger than females. Their skin is mottled gray and white, with dark patches on the back and lighter coloring on the belly, and older narwhals become increasingly pale as they age. Unlike most whales, narwhals do not have a dorsal fin on their backs — instead, they have a low, bumpy ridge, which may help them swim beneath sheets of sea ice. Their rounded, bulging foreheads and small mouths give them a distinctive appearance that sets them apart from other Arctic whales.

Where They Live

Narwhals are found only in the Arctic waters of the Atlantic Ocean, mainly around Canada, Greenland, Norway, and Russia. They prefer deep fjords and coastal areas where pack ice covers the surface for much of the year. During winter, narwhals move offshore to areas of dense pack ice where small cracks and openings called “leads” give them space to breathe. In summer, they migrate to shallower coastal waters where the ice has retreated. Their entire range stays within Arctic and sub-Arctic latitudes, making them one of the most northerly-living mammals on Earth.

What They Eat and How They Dive

Narwhals are impressive deep divers that can plunge to depths of over 1,500 meters (nearly 5,000 feet), making them among the deepest-diving marine mammals. They feed mainly on Arctic cod, Greenland halibut, squid, and shrimp, often hunting near the ocean floor in complete darkness. Rather than chasing prey at high speed, narwhals use suction to pull food into their mouths — they have only two teeth (one of which becomes the tusk in males), so they swallow their prey whole. A single dive can last up to 25 minutes, and narwhals may make dozens of deep dives each day during the winter months. Their flexible rib cages allow their lungs to compress under the intense pressure of the deep ocean without injury.

Narwhals are social animals that typically travel in groups called pods, which usually contain between five and twenty individuals. Pods are often organized by age and sex — groups of females with calves travel separately from groups of young males, while older males may travel alone or in small bachelor groups. During summer migrations, many pods come together and can form enormous gatherings of hundreds or even thousands of narwhals. Mothers give birth to a single calf about every three years after a pregnancy that lasts around 14 months, and calves stay close to their mothers for more than a year. Narwhals communicate with each other using a variety of clicks, whistles, and knocking sounds, which travel well through the cold Arctic water.

The Unicorn Legend

For centuries, narwhal tusks that washed ashore or were brought to Europe by Viking traders were believed to be the horns of unicorns. In medieval Europe, these “unicorn horns” were considered incredibly valuable — they were thought to have magical powers, including the ability to cure poison and disease. Kings and queens paid enormous sums of gold for narwhal tusks, and some were even made into royal scepters and thrones. It was not until the 1600s that European scientists finally realized these “horns” actually came from an Arctic whale. The narwhal’s name itself comes from Old Norse, where “nar” means “corpse” and “hval” means “whale” — a reference to the animal’s pale, mottled skin, which Norse sailors thought looked like a drowned body.

Conservation

Scientists estimate that there are roughly 80,000 narwhals living in the wild today. They are currently listed as “Least Concern” by the International Union for Conservation of Nature, but climate change poses a growing threat to their survival. As Arctic sea ice melts, narwhals lose the icy habitat they depend on, and warming waters may allow new predators and competitors — including orcas — to move into their range. Indigenous Inuit communities in Canada and Greenland have hunted narwhals for thousands of years, and this traditional harvest continues today under regulated quotas. Noise pollution from increased Arctic shipping also concerns scientists, because the sounds from engines and sonar can interfere with the clicks and calls narwhals use to navigate, find food, and communicate with one another.