The narwhal (Monodon monoceros) is a type of toothed whale found in the Arctic. It is the only animal in the genus Monodon and one of two living species in the family Monodontidae. The narwhal has a thick body, a short snout, a large rounded head, and a shallow ridge instead of a dorsal fin. Male narwhals have a long, spiral tusk made of a tooth. This tusk may be used as a weapon, to help find food, to attract mates, or to sense the saltiness of water. Special muscles, flexible neck bones, and the shallow ridge help narwhals move easily through Arctic waters, where they spend long time at great depths. Narwhals share their habitat with beluga whales, and the two species sometimes mate.

Narwhals live in Arctic waters near Canada, Greenland, and Russia. Each year, they travel to summer areas with no ice, usually in shallow waters, and return to the same places each year. They eat Arctic and polar cod, Greenland halibut, cuttlefish, shrimp, and armhook squid. Narwhals can dive as deep as 2,370 meters (about 7,780 feet), making them one of the deepest-diving whales. They usually travel in groups of three to eight, but up to 1,000 narwhals may gather during summer. Narwhals mate near ice from March to May, and their babies are born between July and August the next year. They use clicks, whistles, and knocks to communicate with each other.

There are about 170,000 narwhals alive today. Scientists say the species is not in danger, according to the International Union for Conservation of Nature (IUCN). However, climate change and human activities, such as pollution and hunting, threaten their survival. Inuit people in northern Canada and Greenland have hunted narwhals for thousands of years for food and ivory. This hunting is still allowed in small amounts today.

Taxonomy

The narwhal was first officially named by Carl Linnaeus in his 1758 book Systema Naturae. The word "narwhal" comes from the Old Norse nárhval, meaning "corpse-whale," which may describe the animal's gray, spotted skin and its habit of staying still at the water's surface, a behavior called "logging" that often happens in summer. The scientific name, Monodon monoceros, is from Ancient Greek, meaning "single-tooth, single-horn."

The narwhal is most closely related to the beluga whale (Delphinapterus leucas). These two species are the only living members of the family Monodontidae. Monodontids are known for their large melons (melon-shaped organs used for hearing), short snouts, and lack of a true dorsal fin.

Although the narwhal and beluga are classified as separate genera, some evidence suggests they may mate. In 1990, scientists in West Greenland discovered the remains of a whale with traits between a narwhal and a beluga. This hybrid, called a "narluga," was confirmed by a 2019 DNA study. It is still unknown if this hybrid could reproduce.

A genetic study shows that porpoises and monodontids are closely related, forming a group that split from other dolphins about 11 million years ago. A 2018 study of monodontid fossils suggests they separated from porpoises (Phocoenidae) between 10.82 and 20.12 million years ago. They are considered sister taxa, meaning they are closely related. A 2020 study using mitochondrial DNA found that the narwhal and beluga whale split about 4.98 million years ago.

Fossil evidence includes Casatia thermophila, a species from early Pliocene central Italy, which may be an ancestor of the narwhal. Other extinct genera, such as Bohaskaia, Denebola, and Haborodelphis, are known from Pliocene fossils in the United States. Fossils suggest that ancient monodontids lived in tropical waters and may have moved to Arctic and subarctic regions due to changes in the ocean's food supply.

The following phylogenetic tree is based on a 2019 study of the family Monodontidae:

• Tursiops truncatus (common bottlenose dolphin)
• Phocoena phocoena (harbour porpoise)
• † Haborodelphis japonicus
• † Denebola brachycephala
• † Bohaskaia monodontoides
• † Casatia thermophila
• Delphinapterus leucas (beluga whale)

Description

The narwhal has a strong body with a short, rounded snout, small flippers that curve upward, and tail flukes that are either curved outward or inward. Adult narwhals are 3.0 to 5.5 meters (9.8 to 18.0 feet) long and weigh 800 to 1,600 kilograms (1,800 to 3,500 pounds). Male narwhals reach sexual maturity at 12 to 20 years old and are 3.5 to 4.0 meters (11.5 to 13.1 feet) long. Female narwhals mature at 8 to 9 years old and are about 3.4 meters (11 feet) long. On average, males are 70 centimeters (28 inches) longer and more than 75% heavier than females.

Narwhals have a mottled color pattern, with blackish-brown markings on a white background. When they are born, their skin is light grey. As they grow, white patches appear on their navel and genital area, and this whitening continues throughout their lives, making older narwhals nearly white. Unlike most whales, narwhals have a shallow ridge along their back instead of a dorsal fin. This feature may help them swim under ice or roll more easily. Their neck bones are also separate, not fused like in most whales, allowing greater neck movement. This trait is also found in beluga whales. Male and female narwhals have differently shaped tail flukes: males have flukes that curve inward, while females have flukes that curve backward on the front edges. This difference may help reduce drag caused by the tusk.

Narwhals have strong muscles in their bodies that help them stay active during long dives to hunt for food. These muscles store oxygen, which helps them swim longer and move more easily underwater. They also have a high amount of myoglobin, a protein that helps them dive deeper. Narwhals have a thick layer of blubber, about 50 to 100 millimeters (2.0 to 3.9 inches) thick. This fat makes up one-third of their body weight and helps them stay warm in cold ocean water.

Male narwhals are most easily recognized by their long, spiral tusk, which is a tooth that grows from the left side of the upper jaw. Both males and females have two tusks in their upper jaw, but in males, the tusk on the left side grows through the lip between two and three years of age. The tusk continues to grow throughout the narwhal’s life, reaching lengths of 1.5 to 3 meters (4 feet 11 inches to 9 feet 10 inches). The tusk is hollow and can weigh up to 7.45 kilograms (16.4 pounds). Some males may grow two tusks if the right tooth also grows through the lip. Female narwhals rarely grow tusks, and when they do, the tusks are smaller and less spiral-shaped.

Scientists believe the tusk is a secondary sexual characteristic, meaning it is related to reproduction and helps show social status. Some researchers think narwhals use their tusks in fights, while others believe they help with feeding. The tusk is also a sensory organ with millions of nerve endings that can detect changes in temperature, water pressure, and particle concentration. According to Martin Nweeia, male narwhals may use their tusks to remove encrustations by rubbing them together, rather than fighting. Drone footage from August 2016 in Tremblay Sound, Nunavut, showed narwhals using their tusks to tap and stun small Arctic cod, making them easier to catch. Female narwhals, who usually lack tusks, live longer than males, suggesting the tusk is not essential for survival. It is widely accepted that the main purpose of the tusk is related to sexual selection.

In addition to the tusk, narwhals have a single pair of small vestigial teeth in their upper jaw. These teeth are in open sockets and are surrounded by other teeth. In males, these vestigial teeth are often lost in the palate. The different shapes and structures of these small teeth suggest they are no longer used for their original purpose, showing a path of evolutionary change.

Distribution

The narwhal lives in the Arctic Ocean, specifically in the Atlantic and Russian regions. These animals are often seen in the Canadian Arctic Archipelago, including the northern part of Hudson Bay, Hudson Strait, Baffin Bay, near the east coast of Greenland, and along a strip of land stretching from the northern end of Greenland to eastern Russia (170° east). This area includes places like Svalbard, Franz Joseph Land, and Severnaya Zemlya. The farthest north that narwhals have been seen is near Franz Joseph Land, at about 85° north. Scientists estimate there are about 12,500 narwhals in northern Hudson Bay, while around 140,000 live in Baffin Bay.

Narwhals move seasonally, returning each year to the same ice-free summer areas, which are usually in shallow waters. During summer, they swim closer to the coast, often in groups of 10 to 100. In winter, they travel to deeper waters far from the shore, under thick sea ice. They surface through narrow cracks or larger openings in the ice called leads. When spring arrives, these leads become channels, and the narwhals return to coastal bays. Narwhals in Baffin Bay travel to northern Canada and Greenland from June to September. After this time, they move about 1,700 kilometers (1,100 miles) south to Davis Strait, where they stay until April. During winter, narwhals from Canada and western Greenland travel to the thick sea ice of Davis Strait and Baffin Bay. This area has less than 5% open water and is home to many Greenland halibut.

Behaviour and ecology

Narwhals usually gather in groups of three to eight individuals. These groups can be nurseries where only females and young narwhals are present, or they may include only young narwhals or adult males ("bulls"). Mixed groups can form at any time of the year. In the summer, several groups join together, creating larger groups with 500 to over 1,000 narwhals. Male narwhals have been seen rubbing their tusks together, a behavior called "tusking."

During winter, narwhals make some of the deepest dives ever recorded among whales. They dive at least 800 meters (2,620 feet) more than 15 times each day, with many dives reaching 1,500 meters (4,920 feet). The deepest dive recorded is 2,370 meters (7,780 feet). These dives can last up to 25 minutes and vary in depth depending on the season and the environment. For example, in Baffin Bay, narwhals often dive deep near steep coastlines, typically south of Baffin Bay. This suggests differences in habitat, food availability, or genetic traits between groups. In northern wintering areas, narwhals do not dive as deep as those in the south, even though the water is deeper there. This is likely because food is closer to the surface, which changes how narwhals hunt.

Narwhals have a limited and specialized diet. Because they lack strong teeth, they are believed to feed by swimming close to prey and sucking it into their mouths. A study of the stomach contents of 73 narwhals found Arctic cod (Boreogadus saida) to be the most common prey, followed by Greenland halibut (Reinhardtius hippoglossoides). Large amounts of Boreo-Atlantic armhook squid (Gonatus fabricii) were also found. Male narwhals were more likely to have two additional prey species in their stomachs: polar cod (Arctogadus glacialis) and redfish (Sebastes marinus), both found at depths over 500 meters (1,600 feet). The study also found that the size of prey did not differ between males, females, or age groups. Other items found in narwhal stomachs include wolffish, capelin, skate eggs, and sometimes rocks.

Narwhal diets change with the seasons. In winter, they eat demersal prey, mostly flatfish, under thick ice. In summer, they mainly eat Arctic cod and Greenland halibut, with polar cod making up the rest of their diet. Narwhals consume more food in winter than in summer.

Most female narwhals begin reproducing by the time they are six to eight years old. Courtship and mating behavior occurs from March to May, when narwhals live near offshore ice. It is believed that a dominant male mates with several females. The average pregnancy lasts 15 months, and most births happen between July and August. Female narwhals have a birth interval of about 2 to 3 years. Like most marine mammals, only one calf is born at a time. Newborn calves are about 1.5 meters (4.9 feet) long and have white or light gray coloring. Summer surveys along Baffin Island’s coasts found that calf numbers varied, from 0.05% of 35,000 in Admiralty Inlet to 5% of 10,000 in Eclipse Sound. These results suggest that areas with more calves may be better for giving birth and raising young.

Newborn calves are born with a thin layer of blubber. This layer thickens as they drink their mother’s milk, which is high in fat. Calves depend on milk for about 20 months. This long nursing period allows them to learn survival skills. Narwhals are among the few animals that experience menopause and live for many years after they stop reproducing. Older females may still help protect calves in the group. A 2024 study found that five types of toothed whales evolved menopause to live longer, even though their reproductive periods did not change. Scientists think that calves of these species need help from older females to survive, as raising them alone is very difficult.

Like most toothed whales, narwhals use sound to navigate and find food. They make sounds such

Conservation

The narwhal is classified as a species with low risk of endangerment by the IUCN Red List. In 2017, the global population was estimated to include 123,000 mature individuals out of a total of 170,000. In 2011, about 12,000 narwhals lived in Northern Hudson Bay, and in 2013, around 49,000 were near Somerset Island. Approximately 35,000 narwhals are in Admiralty Inlet, 10,000 in Eclipse Sound, 17,000 in Eastern Baffin Bay, and 12,000 in Jones Sound. In Smith Sound, Inglefield Bredning, and Melville Bay, there are about 16,000, 8,000, and 3,000 narwhals, respectively. Roughly 800 narwhals live in the waters near Svalbard.

In 1972, the United States passed the Marine Mammal Protection Act, which banned importing products made from narwhal parts. Narwhals are listed on Appendix II of CITES and CMS, which limit international trade of live animals and their body parts and promote sustainable practices. In Canada, the species is classified as special concern by COSEWIC, an organization that assesses wildlife risk levels in the country.

In 2025, the United Kingdom protected narwhals under the Ivory Act, which bans trade in narwhal teeth and tusks except for "artistic and cultural artifacts."

Narwhals are hunted for their skin, meat, teeth, tusks, and carved vertebrae, which are sold commercially. About 1,000 narwhals are killed each year: 600 in Canada and 400 in Greenland. Canadian hunts remained steady at this level in the 1970s, dropped to 300–400 per year in the late 1980s and 1990s, and increased again since 1999. Greenland hunts were higher, with 700–900 narwhals killed annually in the 1980s and 1990s.

In Canada and Greenland, narwhal tusks are sold both carved and uncarved. On average, one to two vertebrae and teeth are sold per hunted narwhal. In Greenland, narwhal skin (muktuk) is sold to fish factories, while in Canada, it is sold to other communities. A 2013 study estimated that each narwhal hunted in Hudson Bay in 2007 generated about $6,542 in revenue (equivalent to $6,091 in U.S. dollars). Hunts receive financial support, but they continue mainly to preserve cultural traditions rather than for profit. Economic studies suggest whale watching could provide an alternative source of income.

As narwhals grow, heavy metals build up in their bodies. Ocean pollution is believed to be the main cause of this buildup, which may harm the narwhal population. These metals are found in the blubber, liver, kidney, and muscles. A study found that blubber contained very few metals, while the liver and kidneys had high concentrations. Kidneys had more zinc and cadmium than livers, and lead, copper, and mercury were less common. Differences in metal levels were also observed based on the narwhals’ weight and sex.

Narwhals are among the Arctic marine mammals most affected by climate change, especially in their northern wintering areas like Baffin Bay and Davis Strait. Satellite data shows sea ice in these regions has decreased significantly over time. Narwhals rely on learned foraging patterns from early life to find food during winter, which leads them to return to the same areas repeatedly. This behavior may make them vulnerable to changes in their environment.

Reduced sea ice may increase narwhal exposure to predators. In 2002, hunters in Siorapaluk caught more narwhals than usual, but this increase was not linked to increased hunting effort, suggesting climate change may make narwhals easier to catch. Scientists recommend monitoring population numbers, setting sustainable hunting limits, and ensuring local communities support conservation efforts. Activities like seismic surveys for oil exploration disrupt narwhal migration patterns and may increase the risk of narwhals becoming trapped in ice.

Relationship with humans

Narwhals have lived near people in polar regions for many years. Their long, unique tusks have been a source of interest throughout history. These tusks were believed to have healing powers and were used on staffs and thrones. Artworks like The Lady and the Unicorn often included images of narwhal tusks.

Narwhals have been hunted by Inuit people as much as other sea animals, such as seals and whales. Almost all parts of the narwhal—meat, skin, blubber, and organs—are eaten. Muktuk, which is raw skin and blubber, is considered a special food. Traditionally, one or two vertebrae from each narwhal are used to make tools and art. The skin provides vitamin C, which is hard to find in the Arctic. In some areas of Greenland, like Qaanaaq, hunters use handmade kayaks and harpoons to catch whales. In other parts of Greenland and Northern Canada, hunters use high-speed boats and rifles.

In Inuit stories, a woman who had a harpoon rope tied around her waist was dragged into the ocean after her harpoon caught a large narwhal. She was later turned into a narwhal, and her hair, tied in a knot, became the spiral shape of the narwhal’s tusk.

In Europe, narwhal tusks were highly valued for many centuries. This was because people in the Middle Ages believed the tusks were the horns of the mythical unicorn. These tusks were thought to have magical powers, such as preventing poisoning and treating diseases like measles and rubella. As modern science developed in the late 1600s, belief in magic and alchemy decreased. After scientists proved unicorns did not exist, narwhal tusks were rarely used for magical purposes.

Vikings and Greenland Norse people likely started trading narwhal tusks. These tusks were sent through European trade routes to markets in the Middle East and East Asia. It is not clear if these people hunted narwhals themselves or collected tusks from narwhals killed by orcas. During the 1700s and 1800s, narwhal tusks were given as gifts to European kings and queens. At that time, tusks were worth hundreds of times more than their weight in gold. Ivan the Terrible had a narwhal tusk covered in jewelry on his deathbed, and Queen Elizabeth I received a tusk worth about £10,000 from Martin Frobisher. These items were often displayed in collections of unusual objects.