Narwhal Diet Up Close
Deep Dives and Seasonal Food Sources
Narwhals (Monodon monoceros) are among the Arctic’s most mysterious marine mammals—and their feeding habits are no exception. The narwhal is a type of whale and belongs to the group of toothed whales. Its scientific name is Monodon monoceros, which is the formal scientific name used in taxonomy. Narwhals are closely related to belugas and other Arctic whales. One of their most distinctive features is the spiral tusk, which is typically a single tusk that protrudes from the upper lip of males. This single tusk, with its unique spiral shape, has inspired unicorn legends and is often associated with the mythical unicorn. From deep-water dives in the dark polar winter to seasonal shifts in diet dictated by ice cover, understanding what narwhals eat is key to protecting them in a changing climate.
In this article, we explore how narwhals hunt, what they eat throughout the year, and why their feeding strategies are uniquely adapted to the extreme Arctic environment.
Hunting in the Deep: How Narwhals Find Their Prey
Narwhals are exceptional divers, capable of plunging more than 1,500 meters (4,900 feet) below the surface in search of food. These dives often last 25 minutes or more, allowing narwhals to reach deep-water prey inaccessible to many other marine mammals. Narwhals are known for their ability to dive to great depths, a remarkable adaptation for life in the Arctic.
Narwhal groups can include adult males, and narwhals tend to form social groups based on age and sex. Narwhals tend to hunt in coordinated groups, which helps them locate and capture prey more efficiently.
They rely on echolocation—a biological sonar system—to navigate in the darkness and locate prey such as Greenland halibut and Arctic cod. Narwhals use specialized echolocation clicks to detect prey and avoid obstacles, with these clicks being reflected within the whale's skull to aid in precise environmental sensing. This technique works even in complete darkness under thick sea ice.
Learn more about their tusk adaptations that may aid in hunting in our Narwhal Tusk Research page. The tusk is a long tooth that protrudes from the upper jaw, playing a significant role in the morphology and biological functions of narwhals.
Winter Diet: Surviving the Polar Night
During the long Arctic winter, sea ice and dense pack ice cover much of the narwhals’ habitat in Arctic waters. Narwhals survive beneath the pack ice by relying on breathing holes—openings in the ice that allow them to access air and avoid drowning when the ice cover becomes too thick. Prey is scarcer, and narwhals adapt by targeting deep-water species.
Typical winter diet includes:
Fish such as Greenland halibut (Reinhardtius hippoglossoides) and polar cod (Boreogadus saida)
Shrimp and squid species found at depth
Because food is harder to find, narwhals reduce their activity to conserve energy, relying on specialized diving skills to find enough prey to survive until spring.
Dive deeper into their survival strategies in Narwhal Facts.
Summer Diet: Following the Ice Edge
In summer, the Arctic ice retreats, exposing coastal waters rich in marine life. Narwhals migrate closer to shore, where their diet shifts to take advantage of seasonal abundance. Migration narwhals are characterized by their seasonal movements between key Arctic regions, traveling from deep offshore wintering grounds to shallower summer habitats. Key summer habitats and migration destinations for narwhals include northern Canada, West Greenland, Baffin Bay, Davis Strait, Northern Hudson Bay, and Lancaster Sound. Common summer prey includes:
Arctic cod
Capelin (Mallotus villosus)
Small crustaceans such as krill
This seasonal bounty allows narwhals to build up fat reserves for the coming winter.
See their summer feeding grounds in our Narwhal Photo and Media Collection.
Seasonal Shifts and Climate Change Threats
Narwhals are highly adapted to specific prey types and habitats. Climate change, however, is altering ice cover and ocean temperatures, disrupting the timing and availability of their food sources. In addition to climate change, pollution in Arctic waters has led to the accumulation of heavy metals in narwhals, particularly in their liver and kidneys, raising concerns about bioaccumulation and potential health impacts on the population.
Research shows that warming waters may reduce populations of Arctic cod, one of the narwhals’ staple foods (NOAA Fisheries). The shift in ice conditions could also force narwhals to change migration routes, increasing the risk of energy loss and reduced survival rates. Marine science research is crucial for understanding how these environmental changes affect narwhal behavior, habitat use, and population dynamics. Oceans Canada plays a key role in monitoring and managing narwhal populations within Canadian waters and surrounding oceanic territories. Narwhals are also listed under CITES Appendix II, which regulates international trade to protect the species from overexploitation. Notably, the work of Peter Heide Jørgensen has significantly advanced our understanding of narwhal ecology, population assessments, and conservation in the Arctic region.
Why Understanding Narwhal Diet Matters
Narwhal populations are considered near threatened, and their survival depends on stable prey availability. As Arctic animals and arctic whales, narwhals play a crucial role in the ecosystem. By studying their feeding habits and narwhal research, scientists and Inuit communities can better predict how environmental changes will impact these unique animals. Narwhal tusks, which are actually elongated teeth, hold significant cultural and biological importance; while most male narwhals have one tooth forming a tusk, some individuals can have two tusks, and females may have a small tusk or none at all.
Research on narwhals often includes comparisons with related species such as beluga, belugas, and bottlenose dolphins, which helps broaden our understanding of marine mammals in the Arctic. Polar bears are key predators of narwhals and other animals in the region, highlighting the interconnectedness of the Arctic food web. The narwhal is sometimes called the 'corpse whale' due to its mottled skin coloration, which features white patches and gives older individuals a look reminiscent of a drowned sailor; newborn calves are light grey before developing these distinctive markings.
Identification and sexual dimorphism in narwhals involve differences between male and female narwhals. Males typically have prominent tusks, while females may have a small tusk or none, and these differences in tusks and teeth are important for understanding their roles and behaviors. Males are generally larger, and both males and females contribute to the species' survival in different ways.
Local knowledge, such as that shared in Inuit Wisdom: The Narwhal and in Inuit knowledge, offers vital context for scientific research, bridging traditional observation with modern data.
Key Takeaways
Narwhals are deep-diving specialists, capable of hunting over 1,500 meters below the surface.
Their diet shifts seasonally from deep-water halibut in winter to coastal cod and capelin in summer.
Climate change threatens the availability of their primary prey, posing a serious risk to population health.
