The narwhal, often called the “unicorn of the sea,” is an Arctic whale known for the long, spiraled tusk protruding from its head. This marine mammal inhabits the icy waters of the Canadian High Arctic, Greenland, and Russia. The narwhal is definitively a carnivore, centered on hunting and consuming other marine life in its specialized, frigid environment.
Biological Classification and Carnivory
A carnivore receives its energy and nutrients from a diet consisting primarily of animal tissue. The narwhal fits this definition as a member of the suborder Odontoceti, the toothed whales. Its scientific name is Monodon monoceros, which translates to “single-tooth single-horn.” This classification places it in the same group as dolphins and porpoises, all of which are predators.
As a toothed whale, the narwhal is adapted to a predatory role in the marine food web, despite having very few teeth other than the tusk. It occupies a high trophic level in the Arctic ecosystem. The reliance on a diet exclusively of animal protein confirms its status as a carnivore.
Primary Arctic Prey
The narwhal’s diet is selective, focusing on species that provide the high-fat content necessary for survival in freezing waters. Stomach content analysis reveals that the primary food source is the Greenland halibut, which can be 35 to 55 centimeters long. Arctic cod and polar cod are also major components of the narwhal’s meals, providing a reliable source of protein and fat.
The diet also includes the Boreo-Atlantic armhook squid, which is consumed when other prey is scarce. Various shrimp and smaller crustaceans supplement this core diet. Narwhals consume more food in the winter months, shifting to deep-water prey like demersal flatfish when ice cover is thickest.
Deep-Sea Foraging Strategies
Narwhals are known for their deep-diving capabilities, which are necessary to access their preferred prey. They routinely dive to depths exceeding 800 meters multiple times a day, with some dives recorded as deep as 1,500 meters. These deep excursions allow them to reach populations of Greenland halibut and squid residing near the seabed.
Hunting in the dark, high-pressure environment is guided by echolocation, a biological sonar system. The narwhal emits specialized clicks that bounce off objects, allowing it to navigate and precisely locate prey beneath the sea ice and in the deepest waters. Physiological adaptations, such as a high concentration of myoglobin in the muscles, allow them to store oxygen and remain underwater for up to 25 minutes per dive.
The tusk, an elongated upper-left canine tooth, is directly involved in their carnivorous lifestyle. Recent drone footage has shown narwhals using their tusks to tap and stun small Arctic cod, making the fish easier to capture and swallow whole. The tusk may also act as a sensory organ, detecting changes in water temperature and salinity, which assists in locating prey concentrations.