Narwhals: Mysterious Tusked Whales of the Arctic

Narwhals have long been a source of wonderment. Savvy medieval tradesmen made small fortunes selling their spiralled ivory tusks—which they improperly labelled “horns”—telling tales of unicorns and magical healing properties. In fact, these tusks came from a toothed whale, related to the beluga.

Inuit have a long history of trading narwhal tusks with European and Asian traders, especially during the Viking period of southwestern Greenland. Today, this trade is controlled by various national and international accords, and tusks derived from legitimate narwhal subsistence hunts are sold at a good price.

Carving a narwhal tusk takes great skill because the valuable ivory can be easily broken in the process. However, they are still used to create beautiful works of art. One example is the Mace of the Legislative Assembly of Nunavut in Iqaluit, which is a narwhal tusk adorned with a crown and precious and semi-precious jewels, created by artists Inuk Charlie, Paul Malliki, the late Simata Pitsiulak, Mathew Nuqingaq, the late Mariano Aupilardjuk, and Joseph Suqslaq. The Danish throne also has pillars made of narwhal tusks.

Names & Cultural Meanings

The name narwhal comes from the Norwegian words nar, meaning “corpse”—due to their grey and mottled appearance—and hvalr, meaning “whale.” In Inuktitut, depending on a speaker’s regional dialect, narwhals may be called tuugaalik, qilalugaq, or qilalugaq qernertaq.

Different versions of a well-known Inuit legend say that the narwhal tusk came from the twisted hair of an old Inuk lady, who was holding a harpoon line thrust at a beluga. Her hair twisted as she was dragged by the whale into the water and then hardened into a long, spiralled tusk.

Narwhals have long been a favourite food source of Inuit, who especially prize it for its maktaaq: the thick skin and cutaneous fat that is rich in protein, lipids, and vitamins.

Male & Female Characteristics

In general, male narwhals have a tusk growing out of the left side of the upper jaw. These tusks, which grow straight with a spiralled surface, can be as long as three metres. Males also have an imbedded tusk on the right side of the upper jaw, which erupts into a second external tusk only in rare instances.

Most females have two imbedded tusks in the upper jaw, though a small percentage of adult females have a small slender tusk, much like juvenile males, perhaps caused by high testosterone levels. Narwhals of both sexes are otherwise toothless, unlike their beluga cousins, which have many small conical teeth inside their mouths.

Why Do Narwhals Have Tusks?

What is the purpose of this long ivory tusk? If you google that question, you will find a lot of different claims, some pure speculation and others inferred from scientific studies. Some suggest the tusk is used to spear fish, as a sensor, or to swat fish, but none of these explanations have been convincingly demonstrated.

A study by Helen Gerson (who also published under the name Helen Silverman) out of McGill University, published in Nature in 1980, proposed what is thought by most narwhal researchers to be the most plausible explanation. The tusk, she asserts, is a male attribute used to display their dominance over other males and ensure greater access to females during the reproductive season.

Gerson heard accounts from Inuit and observed for herself the behaviour of male narwhals crossing tusks as if jousting. She proposed that these narwhals measured each other’s dominance by comparing tusk size, much like antlers and tusks are used in other mammalian species.

Like other mammals, when the dominance status between two male challengers goes unresolved by size comparison, the narwhal’s tusk may then be used to fight. Gerson sampled Inuit subsistence narwhal harvests and observed that large mature males, with the largest testicles, had more scarring on their melons (bulbous foreheads) than younger males. This suggested to her that mature males had fought with their tusks more often than juvenile males.

The prevalence of broken tusk tips in large male narwhals also supported her hypothesis that it is used for fighting, since smaller males seldom had broken tips. While summer observations of tusk crossing rarely resulted in aggressive behaviour, it is more plausible that male fighting could take place during the winter mating season.

Other Hypotheses

Gerson’s explanation has the support of most narwhal researchers. Yet, your Internet search on the subject will likely yield reference to other studies that have been widely reported in the popular news and social media.

In particular, one such study claims that the narwhal’s tusk is an oceanographic sensor. The study’s leader, Martin Nweeia, found that tusks have many nerve endings in their hollow centers, as well as small tubular channels to the ivory surface. This suggested to him the tusk must act as some sort of oceanographic sensor.

However, it is not clear how narwhals would use such sensor or why males would have sensors when most females do not! Nweeia advanced this explanation on social media well before he published his research results in peer-reviewed literature, and he didn’t consider other hypotheses for the existence of tusk nerve endings and channels.

It is plausible, for example, that these characteristics of the tusk are related to tactile signals during tusk crossing events. Or perhaps this sensitivity is important to navigate icy surface waters or when feeding along deep bottoms, which could help avoid breaking the appendage that is so valuable in demonstrating their dominant status. These alternate hypotheses have not been investigated.

Narwhal Habitat

In winter, narwhals occupy the deep waters of Baffin Bay and Davis Strait, often feeding at depths in excess of 1,000 metres. Along the slopes of these basins, narwhals dive in search of deep-water fish, particularly Greenland halibut. After fifteen or twenty minutes, they must come up to breathe and, despite the heavy ice cover, they manage to find cracks in the ice to surface. While doing winter marine mammal aerial surveys in Baffin Bay, I have been fortunate to see the backs of hundreds of narwhals along pack ice openings.

In summer, narwhals migrate to smaller passages, fjords, and bays in the Canadian Arctic and northwest Greenland, where the complex coastlines may help hide them from their main predator, the killer whale. Herds of hundreds—sometimes thousands—of narwhals can aggregate in these icy waterways.

Summer is also the period when females give birth, a change which makes them more vulnerable to predation. These migratory areas are a refuge from the open seas where killer whales roam, but, on occasion, killer whales will still find these herds and exact their toll.

Local Inuit have shared stories with marine researchers about narwhals hugging the coastline when killer whales were seen, presumably to become less obvious targets to the predator’s echolocation in shallow water. Scientists have also noted that narwhals become stealthily silent in those instances.

As the Arctic's climate warms, the frequency of killer whale sightings around northern Baffin Island has increased. At the same time, the summer ice cover in smaller passages and bays has diminished, meaning that narwhal—along with other species such as belugas and seals—are becoming more vulnerable to predation.

Spotting Narwhals in the Wild

Narwhals are generally a shy, deep-water whale species. Consequently, they are not easily seen, which adds to their mysterious nature. They generally shy away from ships, being able to hear them from a long distance. On occasion, and with some luck, our ship may encounter a pod of narwhals swimming past in the summertime or autumn. It is always an exciting occurrence, however distant the sightings. On rare occasions, one may even surface next to the ship.

In the autumn, Arctic cod form large aggregations in coastal waters around Devon Island. These enormous schools look like oil in the water because of their dark backsides. Narwhals, as well as belugas, many seals, and birds, take advantage of these schools to eat their fill. With luck, we could come across such aggregations in the last few Arctic expeditions of the season.

While there is never any guarantee of seeing these elusive creatures, spending time out on deck greatly increases your chances of seeing this unique animal! Spotting such cryptically coloured shapes at the water’s surface requires sustained observation from the ship’s decks. Binoculars are often essential.

Adventure Canada expedition team members will alert you if narwhals are spotted, but these can be fleeting moments and they may be gone by the time you make your way up on deck. When we are in areas frequented by narwhals, you are best to spend as much time as you can out on deck, where you’ll also have the chance to spot other marine and terrestrial wildlife.

See you there!